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Data have been taken in several modes :
- clockwise (CW) ,
- counter-clockwise (CCW),
- point-wise (P) at 1degree resolution,
- continuously (C) at 0.2degree resolution,
- point-wise with varying resolution
- around the full azimuth range (F), usually between azimuths 4degree and
440degree
- across smaller azmiuth ranges
The version of plain_telescope.dat used in each instance needs appropriate
maximum antenna and carousel speeds : 0.6degree/sec (normal speed) for the
point-wise data, 0.2degree/sec for the continuous data. Continuous data are
taken with a sample_rate of 1 Hz, giving one record per 0.2degree.
The P-oint-wise data need little preprocessing before being run through INCRED2
apart from reordering the CCW data to a CW format. This is most easily done
using the VMS SORT command, and re-editing the file to restore the two
header lines to the top of the file.
The C-ontinuous data suffer occasional asynchronicity, i.e. where
consecutive entries do not have azimuths that differ by the expected resolution.
This is due, presumably, to variable rotation speeds of the antenna due to
variable rotational resistance. These asynchronicities reveal themselves
particularly during the INCRED2 option to create the difference or mean of
two such files. A little considered editing may be needed to restore these files
to a perfectly ordered sequence.
Iain Coulson
Thu Mar 13 13:57:23 HST 1997