Difference between revisions of "PDS4 Binary Data Type Definitions"

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Definitions for ASCII string representations are on the [[PDS4 ASCII Data Type Definitions]] page.
 
Definitions for ASCII string representations are on the [[PDS4 ASCII Data Type Definitions]] page.
  
'''Last update:''' ''2014-07-17, A.C.Raugh'', Master Schema version 1.2.0.1
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'''Last update:''' ''2015-05-18, A.C.Raugh'', Master Schema version 1.4.0.0 (no changes)
  
 
== Binary Representations ==
 
== Binary Representations ==

Revision as of 13:40, 18 May 2015

Following is a glossary of data type definitions for values in data objects stored in binary (i.e., hardware) formats, extracted from the PDS4 information model and related documents.

Definitions for ASCII string representations are on the PDS4 ASCII Data Type Definitions page.

Last update: 2015-05-18, A.C.Raugh, Master Schema version 1.4.0.0 (no changes)

Binary Representations

ComplexLSB16

This data type consists of a pair of consecutive floating point values of type IEEE754LSBDouble, the sequentially first representing the real part of a complex value and the second representing the imaginary part.


ComplexLSB8

This data type consists of a pair of consecutive floating point values of type IEEE754LSBSingle, the sequentially first representing the real part of a complex value and the second representing the imaginary part.


ComplexMSB16

This data type consists of a pair of consecutive floating point values of type IEEE754MSBDouble, the sequentially first representing the real part of a complex value and the second representing the imaginary part.

ComplexMSB8

This data type consists of a pair of consecutive floating point values of type IEEE754MSBSingle, the sequentially first representing the real part of a complex value and the second representing the imaginary part.


IEEE754LSBDouble

This data type consists of 8 bytes defining a double-precision floating point value as described in the IEEE 754 standard for hardware representation. It is stored so that the least significant byte - the byte containing the lowest-order bits of the mantissa, is sequentially first in storage.


IEEE754LSBSingle

This data type consists of 4 bytes defining a single-precision floating point value as described in the IEEE 754 standard for hardware representation. It is stored so that the least significant byte - the byte containing the lowest-order bits of the mantissa, is sequentially first in storage.

IEEE754MSBDouble

This data type consists of 8 bytes defining a double-precision floating point value as described in the IEEE 754 standard for hardware representation. It is stored so that the most significant byte - the byte containing the bits of the exponent, is sequentially first in storage.


IEEE754MSBSingle

This data type consists of 4 bytes defining a single-precision floating point value as described in the IEEE 754 standard for hardware representation. It is stored so that the most significant byte - the byte containing the bits of the exponent, is sequentially first in storage.


SignedBitString

This data type is a string of bits, not necessarily falling on byte boundaries, in which the first bit indicates a sign.
Usage Note: This storage format is poorly defined. SBN strongly recommends that you do not use this data type.


SignedByte

This data type is a small, two's-complement integer in the range -128 to 127, stored in a single byte.
Usage Note: Any field in a binary table with this data type must have a <field_length> of one byte, but schema validation does not check this as of this writing.


SignedLSB2

This data type is a signed, two-byte, two's-complement integer stored so that the lower-order byte is sequentially first in storage.


SignedLSB4

This data type is a signed, four-byte, two's-complement integer stored so that the lowest-order byte is sequentially first in storage.


SignedLSB8

This data type is a signed, eight-byte, two's-complement integer stored so that the lowest-order byte is sequentially first in storage.
Usage Note: This is not a widely-supported data type. SBN recommends you avoid using it.


SignedMSB2

This data type is a signed, two-byte, two's-complement integer stored so that the higher-order byte is sequentially first in storage.


SignedMSB4

This data type is a signed, four-byte, two's-complement integer stored so that the highest-order byte is sequentially first in storage.


SignedMSB8

This data type is a signed, eight-byte, two's-complement integer stored so that the highest-order byte is sequentially first in storage.
Usage Note: This is not a widely-supported data type. SBN recommends you avoid using it.


UnsignedBitString

This data type indicates a string of bits, not necessarily aligned on a byte boundary, which does not include sign information. Note that it does not imply that the bits are to be interpreted as numeric.
Usage Note: This data type is not well defined. SBN strongly recommends that you do not use this data type.


UnsignedByte

This data type indicates a single byte which contains a small integer in the range 0 to 255.
Usage Note: Any field in a binary table with this data type must have a <field_length> of one byte, but schema validation does not check this as of this writing.

UnsignedLSB2

This data type is an unsigned, two-byte integer stored so that the lower-order byte is sequentially first in storage.


UnsignedLSB4

This data type is an unsigned, four-byte integer stored so that the lowest-order byte is sequentially first in storage.


UnsignedLSB8

This data type is an unsigned, eight-byte integer stored so that the lowest-order byte is sequentially first in storage.
Usage Note: This is not a widely-supported data type. SBN recommends you avoid using it.


UnignedMSB2

This data type is an unsigned, two-byte integer stored so that the higher-order byte is sequentially first in storage.


UnsignedMSB4

This data type is an unsigned, four-byte integer stored so that the highest-order byte is sequentially first in storage.


UnsignedMSB8

This data type is an unsigned, eight-byte integer stored so that the highest-order byte is sequentially first in storage.
Usage Note: This is not a widely-supported data type. SBN recommends you avoid using it.