| The above tables identify key operations during each day of the month and contain:
|
- Day of the month and day of the year.
|
- The primary scan mode for each day.
- Cross Track - elevation scan plane normal to the orbit plane
- Along Track - Azimuth plane coincident with orbit plane during elevation scanning.
- Unrestricted Biaxial - Azimuth plane rotates back and forth through 180 degrees during elevation scanning
- Restricted Biaxial - Azimuth plane rotation restricted when solar beta angle less than 20 degrees.
The beta
angle threshold was increased to 22 degrees May 13, 2005.
|
- Beta Angle - the angle between Sun vector and orbit plane calculated at noon Universal Time [UT].
Values are positive when Sun is on left side of orbit, looking down range.
Terra spacecraft is in Sun-synchronous orbit.
Predicted range of beta angle values is 11 to 28 degrees.
|
- Calibration time in hours, and minutes, UT.
- Internal calibrations with the blackbody and shortwave sources.
- Solar calibrations with the Mirror Attenuator Mosaic at either sunrise or sunset.
|
- Special operations such as ground overflight campaigns.
|
