March 29, 2021




An FAI Lv1 HDF5 file is generated for each FAI image and are zipped together into one zip file for each turn-on session.

The FAI Level 1 HDF5 files contain four objects:

  • A list of operational attributes
  • The FAI image data, in Rayleighs
  • Projected latitude for each corner of each CCD pixel
  • Projected longitude for each corner of each CCD pixel

The file object attributes are listed in the chart below.  In-depth details regarding FAI can be found in reference R1, FAI Characterization Report.

FAI HDF5 Level 1 Operational Attributes:

Attitude Determination ModeStringMode values: 0=”No Solution”, 1=”Coarse Sun Sensors and Magnetometers”, 2=”Coarsely-splined star sensors”, 3=”Moderately-splined star sensors”, or 4=”Finely-splined star sensors”
CCD Temperature (°C)64-bit Floating-pointTemperature of the CCD in degrees Celsius
Camera ModeStringMode values:
7 = Ramp data (no image data, 256×256 pixels, for test purposes only)
5 = High resolution + overscan pixels (264×320 pixels), for test purposes only
4 = High resolution (256 x 280 pixels)
3 = Medium resolution (128 x 140 pixels)
2 = Low resolution (64×70 pixels)
Camera SourceString“NIR (650-1100 nm)” or “Visible (630 nm)”
DN to Rayleigh Conversion Factor (R/DN/s)FloatDetermined from ground calibration, with assumptions (section 2a of the FAI Characterization Report)
Exposure Time (s)FloatCamera exposure time in seconds
Image Projection AvailableBooleanImage projected latitude and longitude arrays are available
Magnetic Latitude (°)FloatSpacecraft position in degrees
Magnetic Local TimeFloatSpacecraft position’s corrected geomagnetic coordinates in hours
Magnetic Longitude (°)FloatSpacecraft position in degrees
Pitch (°)FloatS/C attitude in degrees. See Coordinate Systems.
Roll (°)FloatS/C attitude in degrees. See Coordinate Systems.
Yaw (°)FloatS/C attitude in degrees. See Coordinate Systems.
S/C Altitude (km)FloatKilometers
S/C GEO X Position (km)FloatKilometers
S/C GEO Y Position (km)FloatKilometers
S/C GEO Z Position (km)FloatKilometers
S/C GSM X Position (km)FloatKilometers
S/C GSM Y Position (km)FloatKilometers
S/C GSM Z Position (km)FloatKilometers
S/C Latitude (°)FloatGeographic latitude in degrees
S/C Longitude (°)FloatGeographic longitude in degrees
Source File NameStringRaw data file name HDF is created from
UTCStringUniversal Time
VersionStringe.g. 5b