https://sbnwiki.astro.umd.edu/wiki/index.php?title=Quick_Introduction_to_the_Geometry_Dictionary&feed=atom&action=historyQuick Introduction to the Geometry Dictionary - Revision history2024-03-28T12:38:38ZRevision history for this page on the wikiMediaWiki 1.34.1https://sbnwiki.astro.umd.edu/wiki/index.php?title=Quick_Introduction_to_the_Geometry_Dictionary&diff=2776&oldid=prevRaugh: /* */2019-04-22T17:14:27Z<p></p>
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<tr><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>The Geometry dictionary is a discipline dictionary. As such, its classes are included in the ''&lt;Discipline_Area&gt;'' of your label. In general, you will only have one ''&lt;geom:Geometry&gt;'' class in your label, but it may contain subclasses which are repeated for different targets. For very complex cases, you may also have more than one ''&lt;geom:Geometry&gt;'' class in the ''&lt;Discipline_Area&gt;''.</div></td><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>The Geometry dictionary is a discipline dictionary. As such, its classes are included in the ''&lt;Discipline_Area&gt;'' of your label. In general, you will only have one ''&lt;geom:Geometry&gt;'' class in your label, but it may contain subclasses which are repeated for different targets. For very complex cases, you may also have more than one ''&lt;geom:Geometry&gt;'' class in the ''&lt;Discipline_Area&gt;''.</div></td></tr>
<tr><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"></td><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"></td></tr>
<tr><td class='diff-marker'>−</td><td style="color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #ffe49c; vertical-align: top; white-space: pre-wrap;"><div>:''(For this and the rest of this discussion, I'm going to <del class="diffchange diffchange-inline">ellide </del>the "geom:" prefix in the interest of clarity for explanations, but bear in mind that all the attributes and classes described below ''must'' be placed in the Geometry namespace in PDS4 labels. If that sounds like gibberish to you, see the [[Using Local Dictionaries]] page on this wiki.)''</div></td><td class='diff-marker'>+</td><td style="color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #a3d3ff; vertical-align: top; white-space: pre-wrap;"><div>:''(For this and the rest of this discussion, I'm going to <ins class="diffchange diffchange-inline">elide </ins>the "geom:" prefix in the interest of clarity for explanations, but bear in mind that all the attributes and classes described below ''must'' be placed in the Geometry namespace in PDS4 labels. If that sounds like gibberish to you, see the [[Using Local Dictionaries]] page on this wiki.)''</div></td></tr>
<tr><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"></td><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"></td></tr>
<tr><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>The ''Geometry'' class has five major subclasses:</div></td><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>The ''Geometry'' class has five major subclasses:</div></td></tr>
</table>Raughhttps://sbnwiki.astro.umd.edu/wiki/index.php?title=Quick_Introduction_to_the_Geometry_Dictionary&diff=1955&oldid=prevRaugh: /* */ Update for 1.3.1.02016-08-01T11:40:06Z<p><span dir="auto"><span class="autocomment">: </span> Update for 1.3.1.0</span></p>
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<tr><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>:''(For this and the rest of this discussion, I'm going to ellide the "geom:" prefix in the interest of clarity for explanations, but bear in mind that all the attributes and classes described below ''must'' be placed in the Geometry namespace in PDS4 labels. If that sounds like gibberish to you, see the [[Using Local Dictionaries]] page on this wiki.)''</div></td><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>:''(For this and the rest of this discussion, I'm going to ellide the "geom:" prefix in the interest of clarity for explanations, but bear in mind that all the attributes and classes described below ''must'' be placed in the Geometry namespace in PDS4 labels. If that sounds like gibberish to you, see the [[Using Local Dictionaries]] page on this wiki.)''</div></td></tr>
<tr><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"></td><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"></td></tr>
<tr><td class='diff-marker'>−</td><td style="color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #ffe49c; vertical-align: top; white-space: pre-wrap;"><div>The ''Geometry'' class has <del class="diffchange diffchange-inline">four </del>major subclasses:</div></td><td class='diff-marker'>+</td><td style="color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #a3d3ff; vertical-align: top; white-space: pre-wrap;"><div>The ''Geometry'' class has <ins class="diffchange diffchange-inline">five </ins>major subclasses:</div></td></tr>
<tr><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"></td><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"></td></tr>
<tr><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>#'''&lt;SPICE_Kernel_Files&gt;''': Include this class (once only) to list the SPICE kernels, if any, used to calculate the geometry in the other classes. </div></td><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>#'''&lt;SPICE_Kernel_Files&gt;''': Include this class (once only) to list the SPICE kernels, if any, used to calculate the geometry in the other classes. </div></td></tr>
<tr><td colspan="2"> </td><td class='diff-marker'>+</td><td style="color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #a3d3ff; vertical-align: top; white-space: pre-wrap;"><div><ins style="font-weight: bold; text-decoration: none;">#'''&lt;Expanded_Geometry&gt;''': Use this class to link the observational data to detailed geometry values in a separate data object in this product, or a separate data product. This may be (and usually should be) used in addition to providing median values or ranges in other Geometry classes.</ins></div></td></tr>
<tr><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>#'''&lt;Image_Display_Geometry&gt;''': This class is used to define how the corresponding image should be drawn on a display so that clock angles and directions like North can be correctly interpreted. It contains a required class specifically to define display direction, and optional classes to define image orientation (north/east or RA/Dec), a target, a central body, various clock angles for directions of interest, and a quaternion to define rotation from one frame to another. This class contains orientation values that are useful for ground-based data as well as spacecraft, so if you're dealing with ground-based images, this is where you'll find your applicable values. The class is matched to an Image object in your label using the ''&lt;local_identifier&gt;'' attribute of the image class, which you may omit if there is no ambiguity.</div></td><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>#'''&lt;Image_Display_Geometry&gt;''': This class is used to define how the corresponding image should be drawn on a display so that clock angles and directions like North can be correctly interpreted. It contains a required class specifically to define display direction, and optional classes to define image orientation (north/east or RA/Dec), a target, a central body, various clock angles for directions of interest, and a quaternion to define rotation from one frame to another. This class contains orientation values that are useful for ground-based data as well as spacecraft, so if you're dealing with ground-based images, this is where you'll find your applicable values. The class is matched to an Image object in your label using the ''&lt;local_identifier&gt;'' attribute of the image class, which you may omit if there is no ambiguity.</div></td></tr>
<tr><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>#'''&lt;Geometry_Orbiter&gt;''': This is where you'll find distances, positions, velocities, illumination angles, surface coordinates, and pixel dimensions for observations made by both orbiting and flyby spacecraft. This is itself a large class, and will be described in a little more detail below.</div></td><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>#'''&lt;Geometry_Orbiter&gt;''': This is where you'll find distances, positions, velocities, illumination angles, surface coordinates, and pixel dimensions for observations made by both orbiting and flyby spacecraft. This is itself a large class, and will be described in a little more detail below.</div></td></tr>
</table>Raughhttps://sbnwiki.astro.umd.edu/wiki/index.php?title=Quick_Introduction_to_the_Geometry_Dictionary&diff=1939&oldid=prevRaugh: /* Terminology and Concepts */ Added "observer", additional "target" usage2016-06-29T16:26:39Z<p><span dir="auto"><span class="autocomment">Terminology and Concepts: </span> Added "observer", additional "target" usage</span></p>
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<tr><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>;Object</div></td><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>;Object</div></td></tr>
<tr><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>:In the Geometry Dictionary, the word "object" is used strictly to refer to the digital data object in the data file(s) referenced by the label. It will ''not'' be used to refer to physical objects like planets, comets, rings, dust, spacecraft, instruments, or any other thing that might be found in the field of view or involved in actually recording the observation. So if you are writing a label for an image of Titan, "object" will always mean the image, not Titan.</div></td><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>:In the Geometry Dictionary, the word "object" is used strictly to refer to the digital data object in the data file(s) referenced by the label. It will ''not'' be used to refer to physical objects like planets, comets, rings, dust, spacecraft, instruments, or any other thing that might be found in the field of view or involved in actually recording the observation. So if you are writing a label for an image of Titan, "object" will always mean the image, not Titan.</div></td></tr>
<tr><td colspan="2"> </td><td class='diff-marker'>+</td><td style="color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #a3d3ff; vertical-align: top; white-space: pre-wrap;"><div><ins style="font-weight: bold; text-decoration: none;">;Observer</ins></div></td></tr>
<tr><td colspan="2"> </td><td class='diff-marker'>+</td><td style="color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #a3d3ff; vertical-align: top; white-space: pre-wrap;"><div><ins style="font-weight: bold; text-decoration: none;">:The designation of ''observer'' is used in the Geometry dictionary as a general way of identifying the origin of a vector or other quantity with a sense of direction. So, for example, in the vector class ''&lt;Vector_Cartesian_Position_Sun_to_Spacecraft&gt;'', which defines a position vector from the center of the Sun to the center of the spacecraft, the Sun is in the ''observer'' role and the spacecraft is in the ''target'' role.</ins></div></td></tr>
<tr><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>;Positive Pole</div></td><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>;Positive Pole</div></td></tr>
<tr><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>:This term is used to indicate the direction of positive angular momentum (according to the "right-hand rule") for a body that is rotating. The positive pole may or may not be considered the "north" pole, depending on a number of things including the overall rotational state of the body. Typically, asteroids and comets will be described in terms of their "positive" poles, while larger planets and their satellites will be described in terms of their "north" poles.</div></td><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>:This term is used to indicate the direction of positive angular momentum (according to the "right-hand rule") for a body that is rotating. The positive pole may or may not be considered the "north" pole, depending on a number of things including the overall rotational state of the body. Typically, asteroids and comets will be described in terms of their "positive" poles, while larger planets and their satellites will be described in terms of their "north" poles.</div></td></tr>
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<tr><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>:"SPICE" is an acronym representing a system of data files (called "kernels") and the associated software toolkit that supports them. SPICE is widely used by missions and end-users to calculate observational geometry for spacecraft data, and is very useful for ground-based observers as well. When you see this acronym used in a class or attribute name it indicates that the associated concepts are mapped directly from the SPICE toolkit and documentation. See the NAIF website for details: http://naif.jpl.nasa.gov/naif. In particular, the ''*_spice_name'' attributes should contain the NAIF-issued SPICE identifier for the thing (spacecraft, instrument, reference frame, etc.) being referenced, if any/known.</div></td><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>:"SPICE" is an acronym representing a system of data files (called "kernels") and the associated software toolkit that supports them. SPICE is widely used by missions and end-users to calculate observational geometry for spacecraft data, and is very useful for ground-based observers as well. When you see this acronym used in a class or attribute name it indicates that the associated concepts are mapped directly from the SPICE toolkit and documentation. See the NAIF website for details: http://naif.jpl.nasa.gov/naif. In particular, the ''*_spice_name'' attributes should contain the NAIF-issued SPICE identifier for the thing (spacecraft, instrument, reference frame, etc.) being referenced, if any/known.</div></td></tr>
<tr><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>;Target</div></td><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>;Target</div></td></tr>
<tr><td class='diff-marker'>−</td><td style="color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #ffe49c; vertical-align: top; white-space: pre-wrap;"><div>:The term ''target'' is used in this dictionary to refer to the thing of interest in the enclosing geometry class. It may or may not be the same thing named in the ''&lt;Target_Identification&gt;'' area elsewhere in your label. In fact, if you have multiple things of interest in your field of view, you may well have distinct ''&lt;Geometry&gt;'' classes in your label, each one of which provides geometry for one specific thing of interest ("target"). So ''target'' will be defined locally in your Geometry classes and subclasses. The ''&lt;Geometry_Target_Identification&gt;'' class is used throughout the Geometry dictionary structures to identify a thing of interest as the local ''target'' of reference.</div></td><td class='diff-marker'>+</td><td style="color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #a3d3ff; vertical-align: top; white-space: pre-wrap;"><div>:The term ''target'' is used in this dictionary <ins class="diffchange diffchange-inline">primarily </ins>to refer to the thing of interest in the enclosing geometry class. It may or may not be the same thing named in the ''&lt;Target_Identification&gt;'' area elsewhere in your label. In fact, if you have multiple things of interest in your field of view, you may well have distinct ''&lt;Geometry&gt;'' classes in your label, each one of which provides geometry for one specific thing of interest ("target"). So ''target'' will be defined locally in your Geometry classes and subclasses. The ''&lt;Geometry_Target_Identification&gt;'' class is used throughout the Geometry dictionary structures to identify a thing of interest as the local ''target'' of reference<ins class="diffchange diffchange-inline">.</ins></div></td></tr>
<tr><td colspan="2"> </td><td class='diff-marker'>+</td><td style="color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #a3d3ff; vertical-align: top; white-space: pre-wrap;"><div> </div></td></tr>
<tr><td colspan="2"> </td><td class='diff-marker'>+</td><td style="color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #a3d3ff; vertical-align: top; white-space: pre-wrap;"><div><ins class="diffchange diffchange-inline">:"''Target''" is also employed in a much broader sense when generic classes are used to define vectors that are outside of the specific classes provided in this dictionary. In these cases ''observer'' indicates the origin or starting point, while ''target'' indicates the destination or ending point. Context should make the distinction in meaning clear</ins>.</div></td></tr>
<tr><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"></td><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"></td></tr>
<tr><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>= Label Structures =</div></td><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>= Label Structures =</div></td></tr>
</table>Raughhttps://sbnwiki.astro.umd.edu/wiki/index.php?title=Quick_Introduction_to_the_Geometry_Dictionary&diff=1936&oldid=prevRaugh: /* */2016-06-29T15:45:27Z<p></p>
<table class="diff diff-contentalign-left" data-mw="interface">
<col class="diff-marker" />
<col class="diff-content" />
<col class="diff-marker" />
<col class="diff-content" />
<tr class="diff-title" lang="en">
<td colspan="2" style="background-color: #fff; color: #222; text-align: center;">← Older revision</td>
<td colspan="2" style="background-color: #fff; color: #222; text-align: center;">Revision as of 15:45, 29 June 2016</td>
</tr><tr><td colspan="2" class="diff-lineno" id="mw-diff-left-l38" >Line 38:</td>
<td colspan="2" class="diff-lineno">Line 38:</td></tr>
<tr><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>The ''Geometry'' class has four major subclasses:</div></td><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>The ''Geometry'' class has four major subclasses:</div></td></tr>
<tr><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"></td><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"></td></tr>
<tr><td class='diff-marker'>−</td><td style="color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #ffe49c; vertical-align: top; white-space: pre-wrap;"><div>#'''&lt;SPICE_Kernel_Files&gt;''': Include this class (once only) to list the SPICE kernels used to calculate the geometry in the other classes<del class="diffchange diffchange-inline">, if any</del>. </div></td><td class='diff-marker'>+</td><td style="color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #a3d3ff; vertical-align: top; white-space: pre-wrap;"><div>#'''&lt;SPICE_Kernel_Files&gt;''': Include this class (once only) to list the SPICE kernels<ins class="diffchange diffchange-inline">, if any, </ins>used to calculate the geometry in the other classes. </div></td></tr>
<tr><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>#'''&lt;Image_Display_Geometry&gt;''': This class is used to define how the corresponding image should be drawn on a display so that clock angles and directions like North can be correctly interpreted. It contains a required class specifically to define display direction, and optional classes to define image orientation (north/east or RA/Dec), a target, a central body, various clock angles for directions of interest, and a quaternion to define rotation from one frame to another. This class contains orientation values that are useful for ground-based data as well as spacecraft, so if you're dealing with ground-based images, this is where you'll find your applicable values. The class is matched to an Image object in your label using the ''&lt;local_identifier&gt;'' attribute of the image class, which you may omit if there is no ambiguity.</div></td><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>#'''&lt;Image_Display_Geometry&gt;''': This class is used to define how the corresponding image should be drawn on a display so that clock angles and directions like North can be correctly interpreted. It contains a required class specifically to define display direction, and optional classes to define image orientation (north/east or RA/Dec), a target, a central body, various clock angles for directions of interest, and a quaternion to define rotation from one frame to another. This class contains orientation values that are useful for ground-based data as well as spacecraft, so if you're dealing with ground-based images, this is where you'll find your applicable values. The class is matched to an Image object in your label using the ''&lt;local_identifier&gt;'' attribute of the image class, which you may omit if there is no ambiguity.</div></td></tr>
<tr><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>#'''&lt;Geometry_Orbiter&gt;''': This is where you'll find distances, positions, velocities, illumination angles, surface coordinates, and pixel dimensions for observations made by both orbiting and flyby spacecraft. This is itself a large class, and will be described in a little more detail below.</div></td><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>#'''&lt;Geometry_Orbiter&gt;''': This is where you'll find distances, positions, velocities, illumination angles, surface coordinates, and pixel dimensions for observations made by both orbiting and flyby spacecraft. This is itself a large class, and will be described in a little more detail below.</div></td></tr>
</table>Raughhttps://sbnwiki.astro.umd.edu/wiki/index.php?title=Quick_Introduction_to_the_Geometry_Dictionary&diff=1935&oldid=prevRaugh: /* */2016-06-29T15:44:43Z<p></p>
<table class="diff diff-contentalign-left" data-mw="interface">
<col class="diff-marker" />
<col class="diff-content" />
<col class="diff-marker" />
<col class="diff-content" />
<tr class="diff-title" lang="en">
<td colspan="2" style="background-color: #fff; color: #222; text-align: center;">← Older revision</td>
<td colspan="2" style="background-color: #fff; color: #222; text-align: center;">Revision as of 15:44, 29 June 2016</td>
</tr><tr><td colspan="2" class="diff-lineno" id="mw-diff-left-l38" >Line 38:</td>
<td colspan="2" class="diff-lineno">Line 38:</td></tr>
<tr><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>The ''Geometry'' class has four major subclasses:</div></td><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>The ''Geometry'' class has four major subclasses:</div></td></tr>
<tr><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"></td><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"></td></tr>
<tr><td class='diff-marker'>−</td><td style="color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #ffe49c; vertical-align: top; white-space: pre-wrap;"><div>#'''&lt;SPICE_Kernel_Files&gt;''': Include this class (once only) to list the SPICE kernels used to calculate the geometry in the other classes. </div></td><td class='diff-marker'>+</td><td style="color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #a3d3ff; vertical-align: top; white-space: pre-wrap;"><div>#'''&lt;SPICE_Kernel_Files&gt;''': Include this class (once only) to list the SPICE kernels used to calculate the geometry in the other classes<ins class="diffchange diffchange-inline">, if any</ins>. </div></td></tr>
<tr><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>#'''&lt;Image_Display_Geometry&gt;''': This class is used to define how the corresponding image should be drawn on a display so that clock angles and directions like North can be correctly interpreted. It contains a required class specifically to define display direction, and optional classes to define image orientation (north/east or RA/Dec), a target, a central body, various clock angles for directions of interest, and a quaternion to define rotation from one frame to another. This class contains orientation values that are useful for ground-based data as well as spacecraft, so if you're dealing with ground-based images, this is where you'll find your applicable values. The class is matched to an Image object in your label using the ''&lt;local_identifier&gt;'' attribute of the image class, which you may omit if there is no ambiguity.</div></td><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>#'''&lt;Image_Display_Geometry&gt;''': This class is used to define how the corresponding image should be drawn on a display so that clock angles and directions like North can be correctly interpreted. It contains a required class specifically to define display direction, and optional classes to define image orientation (north/east or RA/Dec), a target, a central body, various clock angles for directions of interest, and a quaternion to define rotation from one frame to another. This class contains orientation values that are useful for ground-based data as well as spacecraft, so if you're dealing with ground-based images, this is where you'll find your applicable values. The class is matched to an Image object in your label using the ''&lt;local_identifier&gt;'' attribute of the image class, which you may omit if there is no ambiguity.</div></td></tr>
<tr><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>#'''&lt;Geometry_Orbiter&gt;''': This is where you'll find distances, positions, velocities, illumination angles, surface coordinates, and pixel dimensions for observations made by both orbiting and flyby spacecraft. This is itself a large class, and will be described in a little more detail below.</div></td><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>#'''&lt;Geometry_Orbiter&gt;''': This is where you'll find distances, positions, velocities, illumination angles, surface coordinates, and pixel dimensions for observations made by both orbiting and flyby spacecraft. This is itself a large class, and will be described in a little more detail below.</div></td></tr>
</table>Raughhttps://sbnwiki.astro.umd.edu/wiki/index.php?title=Quick_Introduction_to_the_Geometry_Dictionary&diff=1934&oldid=prevRaugh: /* */2016-06-29T15:42:46Z<p></p>
<table class="diff diff-contentalign-left" data-mw="interface">
<col class="diff-marker" />
<col class="diff-content" />
<col class="diff-marker" />
<col class="diff-content" />
<tr class="diff-title" lang="en">
<td colspan="2" style="background-color: #fff; color: #222; text-align: center;">← Older revision</td>
<td colspan="2" style="background-color: #fff; color: #222; text-align: center;">Revision as of 15:42, 29 June 2016</td>
</tr><tr><td colspan="2" class="diff-lineno" id="mw-diff-left-l38" >Line 38:</td>
<td colspan="2" class="diff-lineno">Line 38:</td></tr>
<tr><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>The ''Geometry'' class has four major subclasses:</div></td><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>The ''Geometry'' class has four major subclasses:</div></td></tr>
<tr><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"></td><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"></td></tr>
<tr><td class='diff-marker'>−</td><td style="color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #ffe49c; vertical-align: top; white-space: pre-wrap;"><div>#'''&lt;SPICE_Kernel_Files&gt;''': Include this class (once only) to list the SPICE kernels used to calculate the geometry in the other classes<del class="diffchange diffchange-inline">. If the NAIF toolkit was not used to calculate geometry, the class will be absent</del>. </div></td><td class='diff-marker'>+</td><td style="color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #a3d3ff; vertical-align: top; white-space: pre-wrap;"><div>#'''&lt;SPICE_Kernel_Files&gt;''': Include this class (once only) to list the SPICE kernels used to calculate the geometry in the other classes. </div></td></tr>
<tr><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>#'''&lt;Image_Display_Geometry&gt;''': This class is used to define how the corresponding image should be drawn on a display so that clock angles and directions like North can be correctly interpreted. It contains a required class specifically to define display direction, and optional classes to define image orientation (north/east or RA/Dec), a target, a central body, various clock angles for directions of interest, and a quaternion to define rotation from one frame to another. This class contains orientation values that are useful for ground-based data as well as spacecraft, so if you're dealing with ground-based images, this is where you'll find your applicable values. The class is matched to an Image object in your label using the ''&lt;local_identifier&gt;'' attribute of the image class, which you may omit if there is no ambiguity.</div></td><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>#'''&lt;Image_Display_Geometry&gt;''': This class is used to define how the corresponding image should be drawn on a display so that clock angles and directions like North can be correctly interpreted. It contains a required class specifically to define display direction, and optional classes to define image orientation (north/east or RA/Dec), a target, a central body, various clock angles for directions of interest, and a quaternion to define rotation from one frame to another. This class contains orientation values that are useful for ground-based data as well as spacecraft, so if you're dealing with ground-based images, this is where you'll find your applicable values. The class is matched to an Image object in your label using the ''&lt;local_identifier&gt;'' attribute of the image class, which you may omit if there is no ambiguity.</div></td></tr>
<tr><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>#'''&lt;Geometry_Orbiter&gt;''': This is where you'll find distances, positions, velocities, illumination angles, surface coordinates, and pixel dimensions for observations made by both orbiting and flyby spacecraft. This is itself a large class, and will be described in a little more detail below.</div></td><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>#'''&lt;Geometry_Orbiter&gt;''': This is where you'll find distances, positions, velocities, illumination angles, surface coordinates, and pixel dimensions for observations made by both orbiting and flyby spacecraft. This is itself a large class, and will be described in a little more detail below.</div></td></tr>
</table>Raughhttps://sbnwiki.astro.umd.edu/wiki/index.php?title=Quick_Introduction_to_the_Geometry_Dictionary&diff=1933&oldid=prevRaugh at 13:41, 29 June 20162016-06-29T13:41:48Z<p></p>
<table class="diff diff-contentalign-left" data-mw="interface">
<col class="diff-marker" />
<col class="diff-content" />
<col class="diff-marker" />
<col class="diff-content" />
<tr class="diff-title" lang="en">
<td colspan="2" style="background-color: #fff; color: #222; text-align: center;">← Older revision</td>
<td colspan="2" style="background-color: #fff; color: #222; text-align: center;">Revision as of 13:41, 29 June 2016</td>
</tr><tr><td colspan="2" class="diff-lineno" id="mw-diff-left-l11" >Line 11:</td>
<td colspan="2" class="diff-lineno">Line 11:</td></tr>
<tr><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>;Coordinate System ''vs'' Reference Frame</div></td><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>;Coordinate System ''vs'' Reference Frame</div></td></tr>
<tr><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>:In the geometry dictionary, these two terms are distinct, and they are used here the same way they are used in the documentation for the NAIF SPICE toolkit (the software most missions and PDS nodes are using to calculate geometric values for PDS4 labels). A ''Reference Frame'' is defined by three orthogonal axes and an orientation in space; a ''Coordinate System'' is the result of fixing a ''Reference Frame'' to a specific origin. So (loosely speaking), "celestial coordinates" is a ''reference frame'', "celestial coordinates centered on the Sun" is a ''coordinate system''.</div></td><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>:In the geometry dictionary, these two terms are distinct, and they are used here the same way they are used in the documentation for the NAIF SPICE toolkit (the software most missions and PDS nodes are using to calculate geometric values for PDS4 labels). A ''Reference Frame'' is defined by three orthogonal axes and an orientation in space; a ''Coordinate System'' is the result of fixing a ''Reference Frame'' to a specific origin. So (loosely speaking), "celestial coordinates" is a ''reference frame'', "celestial coordinates centered on the Sun" is a ''coordinate system''.</div></td></tr>
<tr><td colspan="2"> </td><td class='diff-marker'>+</td><td style="color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #a3d3ff; vertical-align: top; white-space: pre-wrap;"><div><ins style="font-weight: bold; text-decoration: none;">;Coordinate System ''vs'' Coordinate Space</ins></div></td></tr>
<tr><td colspan="2"> </td><td class='diff-marker'>+</td><td style="color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #a3d3ff; vertical-align: top; white-space: pre-wrap;"><div><ins style="font-weight: bold; text-decoration: none;">:For data obtained by orbiter or flyby spacecraft, labels will generally only need to refer to one or two reference frames, and one or two coordinate systems. But for landed missions, and in particular rovers, the the situation is much more complicated, as coordinate systems are needed to describe in detail the location and orientation of individual pieces of hardware (sampling arms, drills, etc.) that move, as well as the lander/rover itself. New coordinate systems are defined pretty much at every stop, with each of these bootstrapping off of the previously defined coordinate system. Typically, an index is used to identify the individual coordinate system steps in these sequences. The term ''coordinate space'' is used in classes that refer to these indexed sequences of coordinate systems.</ins></div></td></tr>
<tr><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>;North Pole</div></td><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>;North Pole</div></td></tr>
<tr><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>:For solar system objects, the IAU defines the "north" pole of a planet as the pole that is on the same side of the invariant plane of the solar system as the Earth's north pole. For larger planets and satellites, the poles are commonly referred to as "north" and "south" and you will see classes with "north pole" in their name or description. Only use these classes for things that have a well-defined "north". For small bodies, which tend to tumble and have complicated rotational states, "north" is not an applicable concept. For these cases, use classes with the "positive pole" notation, instead.</div></td><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>:For solar system objects, the IAU defines the "north" pole of a planet as the pole that is on the same side of the invariant plane of the solar system as the Earth's north pole. For larger planets and satellites, the poles are commonly referred to as "north" and "south" and you will see classes with "north pole" in their name or description. Only use these classes for things that have a well-defined "north". For small bodies, which tend to tumble and have complicated rotational states, "north" is not an applicable concept. For these cases, use classes with the "positive pole" notation, instead.</div></td></tr>
<tr><td colspan="2" class="diff-lineno" id="mw-diff-left-l39" >Line 39:</td>
<td colspan="2" class="diff-lineno">Line 41:</td></tr>
<tr><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>#'''&lt;Image_Display_Geometry&gt;''': This class is used to define how the corresponding image should be drawn on a display so that clock angles and directions like North can be correctly interpreted. It contains a required class specifically to define display direction, and optional classes to define image orientation (north/east or RA/Dec), a target, a central body, various clock angles for directions of interest, and a quaternion to define rotation from one frame to another. This class contains orientation values that are useful for ground-based data as well as spacecraft, so if you're dealing with ground-based images, this is where you'll find your applicable values. The class is matched to an Image object in your label using the ''&lt;local_identifier&gt;'' attribute of the image class, which you may omit if there is no ambiguity.</div></td><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>#'''&lt;Image_Display_Geometry&gt;''': This class is used to define how the corresponding image should be drawn on a display so that clock angles and directions like North can be correctly interpreted. It contains a required class specifically to define display direction, and optional classes to define image orientation (north/east or RA/Dec), a target, a central body, various clock angles for directions of interest, and a quaternion to define rotation from one frame to another. This class contains orientation values that are useful for ground-based data as well as spacecraft, so if you're dealing with ground-based images, this is where you'll find your applicable values. The class is matched to an Image object in your label using the ''&lt;local_identifier&gt;'' attribute of the image class, which you may omit if there is no ambiguity.</div></td></tr>
<tr><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>#'''&lt;Geometry_Orbiter&gt;''': This is where you'll find distances, positions, velocities, illumination angles, surface coordinates, and pixel dimensions for observations made by both orbiting and flyby spacecraft. This is itself a large class, and will be described in a little more detail below.</div></td><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>#'''&lt;Geometry_Orbiter&gt;''': This is where you'll find distances, positions, velocities, illumination angles, surface coordinates, and pixel dimensions for observations made by both orbiting and flyby spacecraft. This is itself a large class, and will be described in a little more detail below.</div></td></tr>
<tr><td class='diff-marker'>−</td><td style="color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #ffe49c; vertical-align: top; white-space: pre-wrap;"><div>#'''&lt;Geometry_Lander&gt;''': This <del class="diffchange diffchange-inline">is </del>the <del class="diffchange diffchange-inline">class that provides details of individuals motions </del>and orientations for static and articulating hardware used in making observations and measurements on the surface of something other than Earth. <del class="diffchange diffchange-inline"> </del>This section of the Geometry Dictionary is still in development. If you need it, contact your PDS consultant for the information.</div></td><td class='diff-marker'>+</td><td style="color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #a3d3ff; vertical-align: top; white-space: pre-wrap;"><div>#'''&lt;Geometry_Lander&gt;''': This <ins class="diffchange diffchange-inline">class will be a container for all geometric information relating to landed spacecraft, including rovers. It will document </ins>the <ins class="diffchange diffchange-inline">incremental coordinate systems (described as ''coordinate spaces'') for rovers, </ins>and <ins class="diffchange diffchange-inline">the relative </ins>orientations for static and articulating hardware used in making observations and measurements on the surface of something other than Earth. <ins class="diffchange diffchange-inline">'''N.B.:''' </ins>This section of the Geometry Dictionary is still in development. If you need it, contact your PDS consultant for the <ins class="diffchange diffchange-inline">latest </ins>information.</div></td></tr>
<tr><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"></td><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"></td></tr>
<tr><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>== The <Geometry_Orbiter> Subclass ==</div></td><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>== The <Geometry_Orbiter> Subclass ==</div></td></tr>
</table>Raughhttps://sbnwiki.astro.umd.edu/wiki/index.php?title=Quick_Introduction_to_the_Geometry_Dictionary&diff=1932&oldid=prevRaugh at 13:01, 29 June 20162016-06-29T13:01:17Z<p></p>
<table class="diff diff-contentalign-left" data-mw="interface">
<col class="diff-marker" />
<col class="diff-content" />
<col class="diff-marker" />
<col class="diff-content" />
<tr class="diff-title" lang="en">
<td colspan="2" style="background-color: #fff; color: #222; text-align: center;">← Older revision</td>
<td colspan="2" style="background-color: #fff; color: #222; text-align: center;">Revision as of 13:01, 29 June 2016</td>
</tr><tr><td colspan="2" class="diff-lineno" id="mw-diff-left-l8" >Line 8:</td>
<td colspan="2" class="diff-lineno">Line 8:</td></tr>
<tr><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>:Sometimes the field of view contains one thing that is orbiting around another thing. When the smaller thing is the target of interest, ''Central Body'' is the term used to refer to the larger thing that the target is orbiting.</div></td><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>:Sometimes the field of view contains one thing that is orbiting around another thing. When the smaller thing is the target of interest, ''Central Body'' is the term used to refer to the larger thing that the target is orbiting.</div></td></tr>
<tr><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>;Clock Angle</div></td><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>;Clock Angle</div></td></tr>
<tr><td class='diff-marker'>−</td><td style="color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #ffe49c; vertical-align: top; white-space: pre-wrap;"><div>:Clock angles are a way of specifying the direction of something, like North or the Sun, from the center of an image. They are measured clockwise from "up" - a vertical running from the middle of the image to the center of the top edge. In order to correctly interpret a clock angle, you ''must'' be displaying the image correctly. "Correctly", in the PDS case, means according to the explicit display directions included in the ''&lt;geom:Image_Display_Geometry&gt;'' class.</div></td><td class='diff-marker'>+</td><td style="color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #a3d3ff; vertical-align: top; white-space: pre-wrap;"><div>:Clock angles are a way of specifying the direction of something, like North or the Sun, from the center of an image. They are measured clockwise from "up" - a vertical <ins class="diffchange diffchange-inline">line </ins>running from the middle of the image to the center of the top edge. In order to correctly interpret a clock angle, you ''must'' be displaying the image correctly. "Correctly", in the PDS case, means according to the explicit display directions included in the ''&lt;geom:Image_Display_Geometry&gt;'' class.</div></td></tr>
<tr><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>;Coordinate System ''vs'' Reference Frame</div></td><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>;Coordinate System ''vs'' Reference Frame</div></td></tr>
<tr><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>:In the geometry dictionary, these two terms are distinct, and they are used here the same way they are used in the documentation for the NAIF SPICE toolkit (the software most missions and PDS nodes are using to calculate geometric values for PDS4 labels). A ''Reference Frame'' is defined by three orthogonal axes and an orientation in space; a ''Coordinate System'' is the result of fixing a ''Reference Frame'' to a specific origin. So (loosely speaking), "celestial coordinates" is a ''reference frame'', "celestial coordinates centered on the Sun" is a ''coordinate system''.</div></td><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>:In the geometry dictionary, these two terms are distinct, and they are used here the same way they are used in the documentation for the NAIF SPICE toolkit (the software most missions and PDS nodes are using to calculate geometric values for PDS4 labels). A ''Reference Frame'' is defined by three orthogonal axes and an orientation in space; a ''Coordinate System'' is the result of fixing a ''Reference Frame'' to a specific origin. So (loosely speaking), "celestial coordinates" is a ''reference frame'', "celestial coordinates centered on the Sun" is a ''coordinate system''.</div></td></tr>
<tr><td colspan="2" class="diff-lineno" id="mw-diff-left-l20" >Line 20:</td>
<td colspan="2" class="diff-lineno">Line 20:</td></tr>
<tr><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>:Certain geometric quantities recur in data from widely varying sources, and are of particular interest to users, researchers, and analysts. In order to make those data quickly recognizable to both humans and programs, many classes and attributes are defined with "specific" names - names that indicate the observer and/or target. For example, ''&lt;spacecraft_target_center_distance&gt;'' is the attribute that contains the scalar distance between the spacecraft and the center of the target. "Generic" classes, on the other hand, allow a data preparer to define distances between arbitrary points, but require an explicit specification of start and end point. You should use the defined specific classes and attributes wherever they are applicable to support correlative studies across data sources, and use the generic classes only when there is no specific alternative.</div></td><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>:Certain geometric quantities recur in data from widely varying sources, and are of particular interest to users, researchers, and analysts. In order to make those data quickly recognizable to both humans and programs, many classes and attributes are defined with "specific" names - names that indicate the observer and/or target. For example, ''&lt;spacecraft_target_center_distance&gt;'' is the attribute that contains the scalar distance between the spacecraft and the center of the target. "Generic" classes, on the other hand, allow a data preparer to define distances between arbitrary points, but require an explicit specification of start and end point. You should use the defined specific classes and attributes wherever they are applicable to support correlative studies across data sources, and use the generic classes only when there is no specific alternative.</div></td></tr>
<tr><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>;SPICE</div></td><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>;SPICE</div></td></tr>
<tr><td class='diff-marker'>−</td><td style="color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #ffe49c; vertical-align: top; white-space: pre-wrap;"><div>:<del class="diffchange diffchange-inline">This </del>is an acronym <del class="diffchange diffchange-inline">that has come to be </del>the <del class="diffchange diffchange-inline">primary identifier for a </del>toolkit that is widely used by missions and end-users to calculate observational geometry for spacecraft data, and is very useful for ground-based observers as well. When you see this acronym used in a class or attribute name it indicates that the associated concepts are mapped directly from the SPICE toolkit and documentation. See the NAIF website for details: http://naif.jpl.nasa.gov/naif. In particular, the ''*_spice_name'' attributes should contain the NAIF-issued SPICE identifier for the thing (spacecraft, instrument, reference frame, etc.) being referenced, if any/known.</div></td><td class='diff-marker'>+</td><td style="color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #a3d3ff; vertical-align: top; white-space: pre-wrap;"><div>:<ins class="diffchange diffchange-inline">"SPICE" </ins>is an acronym <ins class="diffchange diffchange-inline">representing a system of data files (called "kernels") and </ins>the <ins class="diffchange diffchange-inline">associated software </ins>toolkit that <ins class="diffchange diffchange-inline">supports them. SPICE </ins>is widely used by missions and end-users to calculate observational geometry for spacecraft data, and is very useful for ground-based observers as well. When you see this acronym used in a class or attribute name it indicates that the associated concepts are mapped directly from the SPICE toolkit and documentation. See the NAIF website for details: http://naif.jpl.nasa.gov/naif. In particular, the ''*_spice_name'' attributes should contain the NAIF-issued SPICE identifier for the thing (spacecraft, instrument, reference frame, etc.) being referenced, if any/known.</div></td></tr>
<tr><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>;Target</div></td><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>;Target</div></td></tr>
<tr><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>:The term ''target'' is used in this dictionary to refer to the thing of interest in the enclosing geometry class. It may or may not be the same thing named in the ''&lt;Target_Identification&gt;'' area elsewhere in your label. In fact, if you have multiple things of interest in your field of view, you may well have distinct ''&lt;Geometry&gt;'' classes in your label, each one of which provides geometry for one specific thing of interest ("target"). So ''target'' will be defined locally in your Geometry classes and subclasses. The ''&lt;Geometry_Target_Identification&gt;'' class is used throughout the Geometry dictionary structures to identify a thing of interest as the local ''target'' of reference.</div></td><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>:The term ''target'' is used in this dictionary to refer to the thing of interest in the enclosing geometry class. It may or may not be the same thing named in the ''&lt;Target_Identification&gt;'' area elsewhere in your label. In fact, if you have multiple things of interest in your field of view, you may well have distinct ''&lt;Geometry&gt;'' classes in your label, each one of which provides geometry for one specific thing of interest ("target"). So ''target'' will be defined locally in your Geometry classes and subclasses. The ''&lt;Geometry_Target_Identification&gt;'' class is used throughout the Geometry dictionary structures to identify a thing of interest as the local ''target'' of reference.</div></td></tr>
<tr><td colspan="2" class="diff-lineno" id="mw-diff-left-l37" >Line 37:</td>
<td colspan="2" class="diff-lineno">Line 37:</td></tr>
<tr><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"></td><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"></td></tr>
<tr><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>#'''&lt;SPICE_Kernel_Files&gt;''': Include this class (once only) to list the SPICE kernels used to calculate the geometry in the other classes. If the NAIF toolkit was not used to calculate geometry, the class will be absent. </div></td><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>#'''&lt;SPICE_Kernel_Files&gt;''': Include this class (once only) to list the SPICE kernels used to calculate the geometry in the other classes. If the NAIF toolkit was not used to calculate geometry, the class will be absent. </div></td></tr>
<tr><td class='diff-marker'>−</td><td style="color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #ffe49c; vertical-align: top; white-space: pre-wrap;"><div>#'''&lt;Image_Display_Geometry&gt;''': This class is used to define how the corresponding image should be drawn on a display so that clock angles and directions like North can be correctly interpreted. It contains a required class specifically to define display direction, and optional classes to define image orientation (north/east or RA/Dec), a target, a central body, various clock angles for directions of interest, and a <del class="diffchange diffchange-inline">quarternion </del>to define rotation from one frame to another. This class contains orientation values that are useful for ground-based data as well as spacecraft, so if you're dealing with ground-based images, this is where you'll find your applicable values. The class is matched to an Image object in your label using the ''&lt;local_identifier&gt;'' attribute of the image class, which you may omit if there is no ambiguity.</div></td><td class='diff-marker'>+</td><td style="color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #a3d3ff; vertical-align: top; white-space: pre-wrap;"><div>#'''&lt;Image_Display_Geometry&gt;''': This class is used to define how the corresponding image should be drawn on a display so that clock angles and directions like North can be correctly interpreted. It contains a required class specifically to define display direction, and optional classes to define image orientation (north/east or RA/Dec), a target, a central body, various clock angles for directions of interest, and a <ins class="diffchange diffchange-inline">quaternion </ins>to define rotation from one frame to another. This class contains orientation values that are useful for ground-based data as well as spacecraft, so if you're dealing with ground-based images, this is where you'll find your applicable values. The class is matched to an Image object in your label using the ''&lt;local_identifier&gt;'' attribute of the image class, which you may omit if there is no ambiguity.</div></td></tr>
<tr><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>#'''&lt;Geometry_Orbiter&gt;''': This is where you'll find distances, positions, velocities, illumination angles, surface coordinates, and pixel dimensions for observations made by both orbiting and flyby spacecraft. This is itself a large class, and will be described in a little more detail below.</div></td><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>#'''&lt;Geometry_Orbiter&gt;''': This is where you'll find distances, positions, velocities, illumination angles, surface coordinates, and pixel dimensions for observations made by both orbiting and flyby spacecraft. This is itself a large class, and will be described in a little more detail below.</div></td></tr>
<tr><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>#'''&lt;Geometry_Lander&gt;''': This is the class that provides details of individuals motions and orientations for static and articulating hardware used in making observations and measurements on the surface of something other than Earth. This section of the Geometry Dictionary is still in development. If you need it, contact your PDS consultant for the information.</div></td><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>#'''&lt;Geometry_Lander&gt;''': This is the class that provides details of individuals motions and orientations for static and articulating hardware used in making observations and measurements on the surface of something other than Earth. This section of the Geometry Dictionary is still in development. If you need it, contact your PDS consultant for the information.</div></td></tr>
</table>Raughhttps://sbnwiki.astro.umd.edu/wiki/index.php?title=Quick_Introduction_to_the_Geometry_Dictionary&diff=1923&oldid=prevRaugh: /* The Subclass */2016-06-28T18:44:47Z<p><span dir="auto"><span class="autocomment">The Subclass</span></span></p>
<table class="diff diff-contentalign-left" data-mw="interface">
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<td colspan="2" style="background-color: #fff; color: #222; text-align: center;">← Older revision</td>
<td colspan="2" style="background-color: #fff; color: #222; text-align: center;">Revision as of 18:44, 28 June 2016</td>
</tr><tr><td colspan="2" class="diff-lineno" id="mw-diff-left-l43" >Line 43:</td>
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<tr><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>== The <Geometry_Orbiter> Subclass ==</div></td><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>== The <Geometry_Orbiter> Subclass ==</div></td></tr>
<tr><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"></td><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"></td></tr>
<tr><td class='diff-marker'>−</td><td style="color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #ffe49c; vertical-align: top; white-space: pre-wrap;"><div>This class is repeatable, should you need to. If you have multiple targets about which to report geometry (say, multiple small moons in the same field of view), then you would have a separate ''Geometry_Orbiter'' class for each target. Note that you must have an enclosing ''Geometry'' <del class="diffchange diffchange-inline">in order </del>to <del class="diffchange diffchange-inline">use </del>this class.</div></td><td class='diff-marker'>+</td><td style="color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #a3d3ff; vertical-align: top; white-space: pre-wrap;"><div>This class is repeatable, should you need to. If you have multiple targets about which to report geometry (say, multiple small moons in the same field of view), then you would have a separate ''Geometry_Orbiter'' class for each target. Note that you must <ins class="diffchange diffchange-inline">always </ins>have an enclosing ''<ins class="diffchange diffchange-inline">&lt;</ins>Geometry<ins class="diffchange diffchange-inline">&gt;</ins>'' <ins class="diffchange diffchange-inline">class </ins>to <ins class="diffchange diffchange-inline">contain </ins>this class <ins class="diffchange diffchange-inline">and any siblings</ins>.</div></td></tr>
<tr><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"></td><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"></td></tr>
<tr><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>Every ''Geometry'' class starts with one or more reference times (either a single point in time or a start/stop pair - but you may include both). These indicate the point(s) in time for which the values in the class were calculated. Following that there is a set of classes, each of which is optional, but none of which can be repeated (add a new ''Geometry_Orbiter'' class if you need to).</div></td><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>Every ''Geometry'' class starts with one or more reference times (either a single point in time or a start/stop pair - but you may include both). These indicate the point(s) in time for which the values in the class were calculated. Following that there is a set of classes, each of which is optional, but none of which can be repeated (add a new ''Geometry_Orbiter'' class if you need to).</div></td></tr>
</table>Raughhttps://sbnwiki.astro.umd.edu/wiki/index.php?title=Quick_Introduction_to_the_Geometry_Dictionary&diff=1922&oldid=prevRaugh: /* */2016-06-28T18:43:09Z<p></p>
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<td colspan="2" style="background-color: #fff; color: #222; text-align: center;">← Older revision</td>
<td colspan="2" style="background-color: #fff; color: #222; text-align: center;">Revision as of 18:43, 28 June 2016</td>
</tr><tr><td colspan="2" class="diff-lineno" id="mw-diff-left-l30" >Line 30:</td>
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<tr><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>== <Geometry> ==</div></td><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>== <Geometry> ==</div></td></tr>
<tr><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"></td><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"></td></tr>
<tr><td class='diff-marker'>−</td><td style="color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #ffe49c; vertical-align: top; white-space: pre-wrap;"><div>The Geometry dictionary is a discipline dictionary. As such, its classes are included in the ''&lt;Discipline_Area&gt;'' of your label. <del class="diffchange diffchange-inline">For each set of geometric parameters you want to provide</del>, you will <del class="diffchange diffchange-inline">include </del>one ''&lt;geom:Geometry&gt;'' class in your label. (For this and the rest of this discussion, I'm going to <del class="diffchange diffchange-inline">assume you have defined </del>the "geom:" prefix and <del class="diffchange diffchange-inline">will </del>be <del class="diffchange diffchange-inline">using it to identify classes from </del>the Geometry <del class="diffchange diffchange-inline">Discipline Dictionary</del>. If that sounds like gibberish to you, see the [[Using Local Dictionaries]] page on this wiki.)</div></td><td class='diff-marker'>+</td><td style="color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #a3d3ff; vertical-align: top; white-space: pre-wrap;"><div>The Geometry dictionary is a discipline dictionary. As such, its classes are included in the ''&lt;Discipline_Area&gt;'' of your label. <ins class="diffchange diffchange-inline">In general</ins>, you will <ins class="diffchange diffchange-inline">only have </ins>one ''&lt;geom:Geometry&gt;'' class in your label<ins class="diffchange diffchange-inline">, but it may contain subclasses which are repeated for different targets</ins>. <ins class="diffchange diffchange-inline">For very complex cases, you may also have more than one ''&lt;geom:Geometry&gt;'' class in the ''&lt;Discipline_Area&gt;''.</ins></div></td></tr>
<tr><td colspan="2"> </td><td class='diff-marker'>+</td><td style="color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #a3d3ff; vertical-align: top; white-space: pre-wrap;"><div> </div></td></tr>
<tr><td colspan="2"> </td><td class='diff-marker'>+</td><td style="color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #a3d3ff; vertical-align: top; white-space: pre-wrap;"><div><ins class="diffchange diffchange-inline">:''</ins>(For this and the rest of this discussion, I'm going to <ins class="diffchange diffchange-inline">ellide </ins>the "geom:" prefix <ins class="diffchange diffchange-inline">in the interest of clarity for explanations, but bear in mind that all the attributes </ins>and <ins class="diffchange diffchange-inline">classes described below ''must'' </ins>be <ins class="diffchange diffchange-inline">placed in </ins>the Geometry <ins class="diffchange diffchange-inline">namespace in PDS4 labels</ins>. If that sounds like gibberish to you, see the [[Using Local Dictionaries]] page on this wiki.)<ins class="diffchange diffchange-inline">''</ins></div></td></tr>
<tr><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"></td><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"></td></tr>
<tr><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>The ''Geometry'' class has four major subclasses:</div></td><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>The ''Geometry'' class has four major subclasses:</div></td></tr>
</table>Raugh