Bright Earth Occultation Test for the ACA, 2002-August-20

Individual ACA Image Slot Analysis Details

Separate data for the occultation entry for each used ACA image slot are shown below. Stars were tracked by the ACA in image slots 0 and 2. Monitor windows were used in image slots 4, 5, 6 and 7.

The plots show the time histories of the median or average pixel value and Earth limb angle for each image slot, and the variation of the median or average pixel value with Earth limb angle. In addition, for each of the tracked stars, the time histories of the Y and Z centroid angles and the star magnitude calculated by the ACA are plotted.

For the stars:

The blue lines show when the ACA reports that it is tracking an image.
The red lines show when the ACA set the high background global status bit.
The green lines show when the ACA set any of the image status bits for that image slot, indicating saturated pixels etc.

It can be seen that the ACA showed tracking of the stars, with no global or image status bits set, for Earth limb angles greater than about 7 degrees. The ACA-calculated centroids and magnitudes were also stable at angles larger than 7 degrees. Each of the tracked stars was fainter than magnitude 10.5.

Last modified: 2002-August-30