Nighttime inclinometry was taken during a night of particularly high tau_cso :

    Datasets        HST     mean leg temperatures   Humidity
                   start      start   middle   end       %
 ( 20000701   cw   11:30       8.0     9.0    10.0      30  )
   20000713_1 cw   20:35       9.8     9.0     8.2      70
   20000713_2 ccw  23:40       8.2     7.4     6.9      70
   20000713_3 cw   02:45       6.8     6.2     5.9      70 

The difference between the two new clockwise models and between the second new CW model and the previous model (of 2000 07 01 ) are shown below :

• The first CW dataset contains the obvious spike in the plot above left.

• The formal differences in (F1,F2,F3) in each case are described by the rms scatters of (0.26", 0.08", 0.24") and (0.52", 0.26", 0.41"), respectively, cf (0.47", 0.39", 0.35") previously.

• The new track model was installed at 11:00 HST on 2000 07 14.

• The symmetry remains good : see the plot, implying good structural stability.

• The difference between the CW (mean of 2) and CCW data is shown below :
  

  Apart from additional noise spikes - this time in the new CCW data - this plot is similar enough to the previous CW-CCW pair measured on 2000 05 26, with the F2 and F3 differences being very small, and F1 differing in a manner correlated with the track segments. Such differences as do exist are 1-2" waves on large azimuth scales, much as are seen in any inclinometry difference plots. It all reminds us, however, that the pointing (particularly the azimuth pointing, since F1 impacts azimuth only) will be limited in accuracy until a toggled or hybrid track model is installed.