SUMMARY
Following on from the c.b. loading & inclinometry tests a full circle inclinometry run was completed and a new track model installed. It is little changed from the previous model. Subsequent pointing allowed a new pointing model to be installed also.

   Datasets     HST start      mean leg temperatures   Humidity
                               start   middle   end       %
   inc990308      09:55         1.3     2.1     2.6      25
   inc990312      15:40         4.1     5.1     5.7      22

The difference between the model derived from the new data and the model of 990308 is shown below :

The agreement is good, and the rms scatters in the (F1,F2,F3) differences are fairly small, at (0.59", 0.20", 0.34").
The symmetry remains good (see the plot ), reflecting in part the 'good' new loading .
The new track model was installed at 19:00 HST and pointing with SCUBA done during 1st shift. The weather was poor (tau_cso = 0.20 to 0.22, seeing typically 0.5", worsening to 0.8" at midnight), so it was struggle getting enough decent data. After a few hours we had these 31 data :

There is a clear trend of daz with elevation, indicative of an error in the azimuth encoder zero-point, which could understandably have been affected by the c.b. load adjustments today. The data above elevation 30 degrees (N=26) have rms scatters in (daz,del) of (2.7",1.8"). Running just these through the FIT7 program, to optimize the 7 parameters of the telescope model, gave changes to the previous (old) model given in column 5 below :

 N           OLD    FIXED=1      +          +            NEW

 1           9.5       0        0.0       -0.3           9.2
 2          17.7       0        0.0        0.4          18.1
 3          68.7       0        0.0       -2.8          65.9
 4         171.0       0        0.0        2.0         173.0
 5   319 35 51.2       0        0.0      -13.3   319 35 38.0
 6   351 19 14.6       0        0.0        5.3   351 19 19.9
 7         -12.3       0        0.0        0.4         -11.9

- with the largest change being, as expected, in the azimuth encoder zero-point (parameter #5). This new model was installed, and these data are plotted below as if taken with this new model :

The expected performance, given by the rms scatter in (daz,del), is then (1.2",1.8").

Note :
The 'old' model here was not the one created on 990306, but the one previous to that. The 990306 model was dropped shortly after installation because of (undue) fear that it was causing pointing problems.