Since the last inclinometry, SCUBA2 (weighing ~4 tons) has been on and off the antenna. The new data reported here therefore measure the elasticity of the antenna and track to this cycling of load.

Inclinometry was performed as follows:

    Datasets  El  Dirn     HST     mean leg temperatures   Humidity
                          start     start   middle   end       %
  ( 20080328  89   cw     ~06:30     1.9      2.0     2.4      40 
    20080331  89  ccw     ~07:00     1.1      1.4     2.0      10 )
    20080412  89   cw     ~06:00     2.3      2.4     3.1      60
    20080412  89  ccw     ~09:00     3.1      4.1     5.0      45

Data is recorded from the 3 active inclinometers and one of the two strain gauge channels. The LT trace appears reasonably normal again.

• The differences between the (CW) model derived from these new data and the previous model of 28 Mar are shown below:
  
  Click for better image

• There are some features notably above the noise but of low amplitude. The features of wavelength ~9degrees seen the last two times are gone, and were probably therefore present only in the 20080209 data.

  The rms scatter in the differences in (F1,F2,F3) are (0.32", 0.30", 0.50") cf (0.50", 0.42", 0.75") previously.

• The CW-CCW data are of the 'small amplitude' variety, and were used to generate a hybrid track model which was installed at ~HST 15:30 on 12 April 2008.

  The symmetry and the strain gauge data are also OK - i.e. essentially as before the SCUBA-2 R&R.

  Pointing
  RxA pointing on subsequent nights is summarized below:

            UT       FE       No.     CA  +- dS       IE  +-  dZ
                                        (daz)           (del)
         20080412   RxA       18     +1.2 +- 2.3     -0.5 +- 3.0
         20080413   RxA       13     +0.2 +- 2.2     +1.4 +- 2.3
  

  revealing no change in performance in this regard either.