Unit Classes Standard Values

The PDS4 master schema defines a set of unit classes - related units of measure - to be used for defining label attributes in all dictionaries. Following is a list of these unit classes and the standard values allowed for attributes with that unit type. Case, spacing, and abbreviation all count when it comes to matching values.

Acceleration

• cm/s**2
• km/s**2
• m/s**2

Amount of Substance

• mol

Angle

• arcmin
• arcsec
• deg
• hr
• mrad
• rad

Angular Velocity

• deg/day
• deg/s
• rad/s

Area

• m**2

Frame Rate

• frame/s

Frequency

• Hz

Length

• AU
• Angstrom
• cm
• km
• m
• micrometer
• mm
• nm

Map Scale

• km/pixel
• m/pixel
• mm/pixel
• pixel/deg

Mass

• g
• kg

Miscellaneous Units

• DN
• electron/DN
• pixel

Optical Path Length

• airmass

Pressure

• Pa
• bar
• hPa
• mbar

Radiance

• W*m**-2*sr**-1

Rates

• counts/bin
• kilobits/s

Solid Angle

• sr

Spectral Irradiance

• SFU
• W*m**-2*Hz**-1
• W*m**-1*nm**-1
• W*m**-3
• uW*cm**-2*um**-1

Spectral Radiance

• W*m**-2*sr**-1*Hz**-1
• W*m**-1*sr**-1*nm**-1
• W*m**-3*sr**-1
• uW*cm**-2*sr**-1*um**-1

Storage

• byte

Temperature

• K
• degC

Time

• day
• hr
• julian day
• microseconds
• min
• ms
• s
• yr

Velocity

• cm/s
• km/s
• m/s

Voltage

• V
• mV

Volume

• L
• m**3

Wavenumber

• cm**-1
• m**-1
• nm**-1