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 (630nm)”
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
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 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