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Astrid Scheduling Blocks for PTCS

The scheduling blocks (SBs) are located in /home/groups/ptcs/obs/turtle. In some SBs there is a slight disconnect between the old dictionaries (sources.py) and the new catalog format. In these cases (e.g., GainCurve?.sb) the source must be in both sources.py and the catalog. Also, the configuration is usually hardwired within each SB (e.g., Configure(xband)).

• PointingRunV2.sb: All sky pointing run.

Upon execution the SB will determine the current (Az,El) position and find the nearest pointing source with AutoPeakFocus2?. The SB will step in elevation and then in azimuth. The exact (Az,El) location of the calibrator search is slightly adjusted by a random number generator. N.B., if nPeak is set to a large number (>100) it takes very long to validate. So typically you can set nPeak to 25 and submit several SBs to the queue. The sky coverage can be effected by these SB transitions since the history of the (Az,El) direction is lost from one SB to another. Therefore, in V2 we have added code that will store this history in an ascii file (azElDirection.txt). This file contains two integers that specify the direction of the step (azStep for Az and elStep for El) as 1 (increasing) or -1 (decreasing). N.B., during validation, and therefore when a SB is saved to the database, the file azElDirection.txt can be altered.. It is usually best to keep doConfig = True when leaving the script with the operator. If they have to exit Astrid for some reason then they have to configure at least once. The configuration now is much faster and little time will be lost.

• OffsetPointingRun.sb: Offset pointing run.

This SB performs a Peak/Focus using AutoPeakFocus2? for a Condon double or triplet and repeats this cycle nPeak times.

• HalfPower.sb: Half-power tracking.

This SB will perform a NOD using the current LPCs. The procedure would be to set doConfig, doPeakFocus, and doNodTrack all equal to True which will peak up and then track this center position. Then set doConfig and doPeakFocus to False. Modify the LPCs to offset to the desired half-power point and run the SB again. In the future we could use some of the code in Subreflector.py to make this more automatic.

• GainCurve.sb:

Performs a series of Peak/Focus/Nod/OOF measurements on a source list and surface model list. That is, it iterates over a source list and for each source it iterates over a list of surface models. This SB uses PeakNSurface?.py which is based on AutoPeakFocus2?. The different surface models are located in: /home/groups/ptcs/surfmodels.

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• TestSubLPCs.sb:

This was written to test if the pointing errors measured during the day were due to subreflector motion. The SB will perform Peak/Focus/Nod/OOF measurements with LPCs or with these LPCs taken out and put into the subreflector (LFCs). N.B., Validation offline could cause changes in the real system. Comment lines with SubLPC?() and ZeroSubLPCs?() which use the Grail Client in the file Subreflector.py

-- DanaBalser - 25 Mar 2006

• Drift.sb: Drift scans

This SB moves the telescope ahead of a specified position, holds this position and waits for the Earth to rotate the beam past the source. It was meant to be used on sources near the north pole to check to see if the pointing hysteresis problem was related to a timing problem. It was tested once and seemed to work fine.

• moonscans.sb: Moon scans at Q-band

This SB was used to make 4-degree and 8-degree wide scans across the Moon with the DCR and the Q-band receiver.

• Doubles.sb: Observe Condon doubles (pairs of quasars with small separation)

There are 7 pairs of doubles that are within about 2 degrees of one another, as well as 3 triples. This SB observes one member of the pair using a standard Peak scan, and then the other member with modified Peak scan (Peak2) in which the scan length can be different between the forward and backward scans. This was to try to test for correlated vibrational effects in pointing scans.

• Circle2.py: Drives the telescope in a small circle about a source

This SB is used to test the telescope performance in following a circle. If the radius is set to the beam radius, then the receiver total power can be used to determine how closely the beam is following the projected path (assuming a non-elliptical beam). Located in /home/groups/ptcs/obs/servo

-- ToddHunter - 20 Aug 2007