CASSIOPE SPACECRAFT (Swarm-E)
PROCESSED DATA HANDBOOK
FAI Lv1 HDF5
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:
| Attribute | Type | Definition |
| Attitude Determination Mode | String | Mode 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-point | Temperature of the CCD in degrees Celsius |
| Camera Mode | String | Mode 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 Source | String | “NIR (650-1100 nm)” or “Visible (630nm)” |
| DN to Rayleigh Conversion Factor (R/DN/s) | Float | Determined from ground calibration, with assumptions (section 2a of the FAI Characterization Report) |
| Exposure Time (s) | Float | Camera exposure time in seconds |
| Magnetic Latitude (°) | Float | Spacecraft position in degrees |
| Magnetic Local Time | Float | Spacecraft position’s corrected geomagnetic coordinates in hours |
| Magnetic Longitude (°) | Float | Spacecraft position in degrees |
| Pitch (°) | Float | S/C attitude in degrees. See Coordinate Systems. |
| Roll (°) | Float | S/C attitude in degrees. See Coordinate Systems. |
| Yaw (°) | Float | S/C attitude in degrees. See Coordinate Systems. |
| S/C Altitude (km) | Float | Kilometers |
| S/C GSM X Position (km) | Float | Kilometers |
| S/C GSM Y Position (km) | Float | Kilometers |
| S/C GSM Z Position (km) | Float | Kilometers |
| S/C Latitude (°) | Float | Geographic latitude in degrees |
| S/C Longitude (°) | Float | Geographic longitude in degrees |
| Source File Name | String | Raw data file name HDF is created from |
| UTC | String | Universal Time |
| Version | String | e.g. 5b |