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Determine Pointing Offsets


This process can now be achieved under computer control (either by the controller or observer).

  1. Ask the controller to give control of the telescope to arthur, if it is not already.
  2. Stop any current integration.
  3. If you wish the controller to run offset scans, he should start the PSRCONTROL program in the usual way for timing, then select OFFSETS from the main menu.
  4. If you wish to run the program yourself, log in to ARTHUR as PULSAR (or a pulsar group account) and type OFFSET1. The procedure is now the same for observer or controller.
  5. Configure the scan routine from the OFFSET startup menu. In general the default values are recommended and you should only need to select a source).
  6. The program will make two scans along the initial scan axis, measuring signal levels (on both polarisations summed) through the Pulsar timing hardware (filter bank and DDU)
  7. A gaussian is fit to the scans and the axis offset is set to the value found.
  8. two furthur scans are made and fitted along the other axis.
  9. Offset values are given and can be noted down as the program progresses, but more accurate values can be obtained after the scans are finished, by running PLOTOFFSET 1. This process incorporates some spike rejection, and produces a graphics output for posterity.
  10. File the offset graph in the Pulsar calibration folder, note the values in the log book and update the default parameter file using MENU

Jon Bell
Sun Aug 17 17:32:08 BST 1997
Mod: Oct 21 1999 cajordan