How good are the aspect solutions believed to be?
The aspect solutions are screened to exclude intervals where RA/Dec errors are greater than 1", and if the attitude drifts from a nominal pointing by more than 15'. A systematic error of approximately 10" remains due to ground calibration procedures. A corrector lens was introduced to simulate orbit vacuum, and a mounting error of 10 microns can explain the residual 10" pointing error. Solutions are being worked on to improve the aspect.
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