New Conventional Inclinometry - including doors open -vs- doors closed

SUMMARY
During poor weather, conventional nighttime inclinometry was obtained, and a new track model installed for the first time since 981117. CW runs with the dome doors closed are little different from data taken with the doors open.

   Datasets          HST start      mean leg temperatures   Humidity
                                    start   middle   end       %
   inc990107  (open)   21:15         4.5     4.1     3.7      60
   inc990108 (closed)  00:20         3.4     3.1     3.1      65

The differences between the models derived from these new data and between the models of 990107 and 981117 are shown below :

The data show a couple of electronic spikes (located within the 990107 data) which were removed before the creation of the track model. There is otherwise good agreement between data taken with the doors open and closed : rms scatters in the (F1,F2,F3) differences of (0.25",0.23",0.52"). Between the models of 990107 and 981117 the differences are somewhat worse at (1.0",0.4",0.6"), but not bad in the context of recent problems. A small amplitude ripple is present in the latter plot that is suggestive of a change in the ripple characteristics of one of the wheels. This is analysed further below.

L-R symmetry
The 990107 data are used to update the symmetry measures, reverting to using RY as a reference :

'Good' symmetry persists. The plot of these symmetry data is updated.

The data are also used to update the plot showing the amplitude and phase of the ripples in the right and left A-frame inclinometry data. A substantial reduction in the ripple from the right side is evident, as was suggested by the inspection above.

Conclusions

• A new track model was installed on 990108. It appears little different from that in use these past 7+ weeks.
• The state of the dome doors seems unimportant to the inclinometry measures of the track.