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Settle_time and Sample_time

The Point-Wise method of taking data requires specifying two times; viz, the settle_time - the time in seconds between the antenna reaching the demand position and the start of integration - and the sample_time - the time in seconds spent sampling the inclinometers. The tests below were made at (az,el) = (270,89.9) with various combinations of settle-time and sample_time, and the data analysed for means and standard deviations in each inclinometry output channel (in mV) :

  Dataset   settle  sample   Ch     1       2       4       5       7       8
             time    time      
            (secs)   (secs)       TMUX    TMUY     LX      LY      RX      RY

  S270_4_1     4      1           60.5  -230.5    37.7   -52.6   106.9  -318.9
                             +-    3.0    19.8     0.6     0.6     1.2     1.1

  S270_4_2     4      2           63.5  -250.6    34.1   -53.8   108.9  -319.4
                                   0.5     1.8     0.8     0.8     0.8     0.7

  S270_4_3     4      3           62.5  -247.4    31.0   -54.5   110.1  -319.7
                                   0.8     0.8     1.2     0.3     0.4     0.4

  S270_3_1     3      1           61.1  -248.9    29.5   -55.6   111.5  -320.6
                                   0.6     2.8     0.8     0.9     0.9     1.1

  S270_3_2     3      2           60.9  -253.2    28.7   -54.7   113.7  -320.4
                                   0.6     1.4     0.7     0.5     1.1     0.6

  S270_3_3     3      3           59.2  -254.4    27.4   -54.7   117.4  -320.7
                                   0.4     1.0     0.6     0.9     0.6     0.5
These data suggest settle_time = 4 and sample_time = 2 as optimal values.

Illustrative Point-Wise datasets : OUTCW1, OUTCCW1, (940923), and CW25 (940925).





Iain Coulson
Thu Mar 13 13:57:23 HST 1997