990729 report
Pointing with the new Telecope Control Software
SUMMARY
Tracking of Jupiter was done using the new TCS, and at this level
seems to have done so successfully.
Jupiter is not an ideal pointing source, being so large, so the
results probably only show that the TCS is performing well.
The offset between the Jupiter data and the one very low elevation
point on the much smaller Venus
indicates a systematic error in the Jupiter data from the expected
collimations, which detracts further from its usefulness for this
purpose. Anyhow, allowing all of the 7 parameters of the telecope model
to vary in order to minimize the residuals
produces the 'fit' below :
The azimuth residuals are now nicely randomized, although the same
cannot be said for the elevation residuals, probably indicating
that
the data are unsuited for the purposes of updating the model.
The suggested changes to the model are shown below, although
the large change in parameter #6 - the elevation zero-point - is
just a reflection of the systematic elevation error on Jupiter
mentioned above :
PT990729C.DAT
model # 490
RXB
No. of points = 101
N OLD FIXED=1 + + NEW
1 11.2 0 0.0 -2.5 8.7
2 17.8 0 0.0 -1.1 16.7
3 50.9 0 0.0 7.7 58.6
4 158.8 0 0.0 1.8 160.6
5 229 55 26.1 0 0.0 11.3 229 55 37.4
6 351 19 21.5 0 0.0 -21.5 351 18 59.9
7 -13.1 0 0.0 10.6 -2.5
8 0.0 1 0.0 0.0 0.0
9 0.0 1 0.0 0.0 0.0
daz = 0.0 +- 1.6 del = 0.0 +- 2.1 vec = 2.2 +- 1.4
The offset in elevation between Jupiter and Venus persists,
but this exercise may still suggest that the
model may need improvement and that a more appropriate dataset be
obtained for that purpose soon.
Primarily, there is no evidence
that the TCS is handling the pointing or track models in any way
incorrectly.
Iain Coulson
29 July 1999
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