Inclinometry was done as follows :

    Datasets  El Dirn     HST     mean leg temperatures   Humidity
                          start     start   middle   end       %
  ( 20030328  90  cw      22:50       6        5      4       85
    20030329  90  ccw     01:20       4        3      2       85 )
    20030405  90  cw      11:19      3.5      5.0    6.0      40

All data channels were OK : the spike at azimuth ~310 is ignored. The resulting CW model is compared with previous CW model -- the one taken on 29 Mar:

The new data are not significantly different from those of Mar 29. They are used to create a new track model.

• The differences in (F1,F2,F3) are described by the rms scatters of (0.23", 0.15", 0.38") c.f. (0.36", 0.39", 0.48"). previously.

• Updates have been made to the plots of symmetry and strain gauge data. All looks OK.

• The CW model was installed at 11:30 HST on 07 Apr 2003.

20030412
This model was merged with the mean (CW-CCW) file to create the JCMT's first hybrid model model using azimuths of 70 and 290 as the toggle points, in accordance with optimization described previously. There are still parts of the (az,el) domain in the north, where sources are moving clocwise, where this hybrid model is still formally inapplicable, and the aforementioned document illustrates those. However, even in those places the amplitude of the error is small, and the overall performance should be better than having an inappropriate (CW) track model in place for almost the entire northern sky.