We have compiled statistics on guide star tracking success covering
the period Jan-2001 through May-2003. The key results are:
- Only 0.45% (39 of 8623) of the unique guide stars were tracked for less
than 95% of the Kalman filter dwell time. We use this criterion
to define a "successfully tracked" guide star
- 19 of these 33 were not acquired at all, while the rest
were tracked between 1% - 95% of the time
- A fraction 0.62% (5 of 799) of stars with COLOR=1.500 were not successfully
tracked
- Nearly 50% (8 of 17) of stars with no color information
(COLOR=0.700) were not successfully tracked
- Three science observations (obsids 2882, 3062, 3018) had only
three tracked guide stars for a significant fraction of the
observation. All three obsids had hand-edited (SFE) star
catalogs with 5 commanded guide stars
- The magnitude distribution of failed guide stars is consistent
with the distribution of successfully tracked stars (see plot
below)
- With the exception of the special cases COLOR=0.700 and
COLOR=1.500, the color distribution of failed guide stars is
roughly consistent with the distribution of successfully tracked
stars (see plot below)
|
