Change to temp_slope

Recent pointing data has revealed a need to change the value of temp_slope , which relates the elevation residual, del , to the temperature difference between the front and back legs, (Tf-Tb) . SCUBA pointing data from the last 2 weeks have been analysed for the slope in their relationship :

    date/dataset   N_obs   slope  +-    range of (Tf-Tb) 

      971206        26     -4.6   1.3     -0.4 to 0.6  * 
          07        30     -4.5   0.9     -0.2    0.9  *     
          08        22     -5.3   1.1     -0.4    0.8  *
          09        23     -4.6   1.1     -0.3    0.8  *
          10        24    -11.6   1.8     -0.6    0.1
          11        14     -2.7   6.5     -0.2    0.1
          12        15     -4.6   1.7     -0.2    0.8  *
          13        20     -4.5   1.5     -0.4    0.4
          16        35     -2.6   1.1     -0.6    0.0
          17        49     -4.5   0.8     -0.4    0.7  *
          18        41     -7.9   1.0     -0.2    0.8  *
          19         9     -5.9   2.3     -0.2    0.6  *
          20        17     -3.0   1.7     -0.5    0.0
          21        13     -3.4   1.3     -0.2    0.5

The data yield odd or uncertain values when the range of temperatures covered is incomplete. The subset (*) comprising those datasets wherein (Tf-Tb) reaches 0.6 or more is shown below :

and the trend of del with (Tf-Tb) :

shows the necessity of changing the value of temp_slope , currently 3.5, by +5.1, to 8.6 ("/deg).

This has been been done, and should improve pointing during dusk and dawn.

Note also that this is a return to a value in concert with early FEA studies.