next up previous contents
Next: Conclusions Up: No Title Previous: Implications for the

The September Dataset

The Point-Wise data OUTCW1, OUTCCW1 and CW25 are sufficiently similar that the mean of the two CW runs (OUTCW1 and CW25) were used to create CW940925 (see above) that represents our most reliable CW data and our confidence that it reflects the CCW data bar random errors.

This dataset has been used to create the track model MODEL1-940925 which has been used since that date. This model is shown in Fig.7. As reported on 941018 the performance of this model, and the accompanying 7-parameter antenna model, has been confused because of problems caused by the September heavy engineering. However, it has become apparent that the elevation pointing (from all-sky data) has improved considerably, from rms errors of about 2.0" to about 1.4". This is probably because the TMU-Y axis measures the elevation pointing correction directly and is now simply doing it better than previously. The lack of associated and clear improvement in the azimuth pointing is perhaps because the theory of conversion from A-frame inclinometry to yaw is flawed (see above). Early tracking experiments (on Saturn, from (az,el) = (163,58) to (180,59), passing over 4 track joints) gave rms errors of (0.3", 0.3") (16 points logged) - which is the encoder resolution limit !!



Iain Coulson
Thu Mar 13 13:57:23 HST 1997