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operations:documentation.test_antenna
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operations:documentation.test_antenna [2012/12/03 22:22] Jim Lovell [Antenna pointing check] |
operations:documentation.test_antenna [2016/07/04 16:05] (current) Jesse Swan |
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| ===== Antenna Controller Clock ===== | ===== Antenna Controller Clock ===== | ||
| - | The antenna Controller (in the pedestal) gets its time from the NTP server on the local GPS CNS-II clock. If it doesn't know the time, it can't point the antenna. Check the System Monitor display and make sure "Controller clock" is OK. If not, there's a problem. Check the HMI interface on time[hb|ke|yg] and look for the "Current time" section half-way down the right-hand side. MJD should be correct and the seconds should be ticking over. You should also see CLOVK INITIALIZED and SNTP SERVER OK with green backgrounds. If this doesn't look right, consult the On Call person. | + | The antenna Controller (in the pedestal) gets its time from the NTP server on the local GPS CNS-II clock. If it doesn't know the time, it can't point the antenna. Check the System Monitor display and make sure "Controller clock" is OK. If not, there's a problem. Check the HMI interface on time[hb|ke|yg] and look for the "Current time" section half-way down the right-hand side. MJD should be correct and the seconds should be ticking over. You should also see CLOCK INITIALIZED and SNTP SERVER OK with green backgrounds. If this doesn't look right, consult the On Call person. |
| ===== Antenna in Remote ===== | ===== Antenna in Remote ===== | ||
| - | Check the System Monitor that the Drive control is in "Remote". If it isn't you won't be able to move the antenna. Cann the local support person at the site for assistance. | + | Check the System Monitor that the Drive control is in "Remote". If it isn't you won't be able to move the antenna. Call the local support person at the site for assistance. |
| ===== Antenna pointing check ===== | ===== Antenna pointing check ===== | ||
| Line 35: | Line 35: | ||
| initp | initp | ||
| </code> | </code> | ||
| - | Then choose a source from /usr2/proc/point.prc (e.g. 1618m49, hydra, virgoa, etc). Sources to choose from: | + | Then choose a source from /usr2/proc/point.prc (e.g. 1618m49, hydra, virgoa, etc). (The [[operations:documentation:monan|monan]] display can be started if you want to check the sidereal time.) Sources to choose from: |
| <code> | <code> | ||
| Source RA Dec | Source RA Dec | ||
| Line 54: | Line 54: | ||
| fivept | fivept | ||
| </code> | </code> | ||
| - | Look for first number in latfit (El), xoffset (cross-el) | + | Be prepared to wait for 5 to 10 minutes for a result. Fivept does step-by-step offsets (9 points each) in Elevation, the Azimuth. It will probably try again if it fails the first time. When finished, look for the third and fourth numbers xoffset. These are the pointing offsets in degrees. For a more detailed description of ''fivept'' see [[operations:documentation:fivept_output|Fivept Output: What does it mean?]] but briefly, you should see something like this: |
| - | Total pointing offsets should generally be less than ~0.02 degrees. Total pointing offsets greater than 0.04 are considered to be critical and require immediate investigation. Pointing offsets less than this should be dealt with as soon as possible after the observation. | + | <code> |
| + | Az El Lon_offs Lat_offs | ||
| + | 2013.043.22:40:13.21#fivpt#xoffset 210.7833 5.4745 -0.00319 0.02518 0.01481 0.00850 1 1 | ||
| + | </code> | ||
| - | A SEFD check can be made using the new pointing offsets with a <code>onoff</code> | + | Where ''Az'' and ''El'' are the antenna Azimuth and Elevation that the fit was done, ''Lon_offset'' is the cross-El pointing offset in deg and ''Lat_offs'' is the Elevation pointing offset in deg. |
| - | Zero offsets with <code>azeloof=0d,0d</code> | + | Total pointing offsets should generally be less than ~0.02 degrees. Offsets greater than 0.04 are considered to be critical and require immediate investigation. Pointing offsets less than this should be dealt with as soon as possible after the observation. //To fix offsets between ~0.02 and 0.04 run the fivept command again after setting the AZ and EL offsets to zero (see a few steps below).// |
| - | And revert to the nominal DBBC Conditioning Module target power levels with a <code>proc=<experimentcode><station> | + | A SEFD check can be made using the new pointing offsets with a <code>onoff</code> |
| - | setupsx</code> | + | |
| - | ==== Alternative Antenna pointing/SEFD check ==== | + | |
| - | At the moment the PCFS does a good job at pointing checks but not so good with SEFD (DBBC issues). Here's an alternative method that may produce more reliable SEFD estimates as it uses the broadband power meter. | + | Look at the column of SEFD values reported at the end of an onoff command. The "Center" column tells you the frequency they were observed at (in MHz). All values for S (~2100 to 2400 MHz) and X-bands (~8100 - 9100 MHz) should be 3500 to 4000 Jy. Note at the moment though that the reported values can be non-sensical. We think this is a bug in the software or in the limited resolution provided by the DBBC. //For now, don't worry about reporting SEFD values in the start messages.// |
| - | On the pcfs machine, run ''/usr2/oper/prePoint.sh''. This script will automatically select a source and carry out a series of three grid-pointings on the source and report back some information on the measured offset and source amplitude. If the source is recognised as a standard flux calibrator, it will also report back and estimated SEFD at X-band. It will then select another source and carry on until instructed to stop. | + | Zero offsets with <code>azeloff=0d,0d</code> |
| - | An example of the output of the script is included below. | + | (make sure there is no space between the 0d and 0d) |
| - | <file>oper@pcfshb:~$ ./prePoint.sh | + | And revert to the nominal DBBC Conditioning Module target power levels with a <code>proc=<experimentcode><station> |
| - | Please note that the first scan is usually unreliable... | + | setupsx</code> |
| - | Selected source is 0857-43 | + | |
| - | 0857-43 | + | |
| - | 2.54602558e+02 6.20529151e+01 -7.18278453e-03 -1.18138754e-02 5.71477606e-02 8.07570616e+00 | + | |
| - | 2.54504080e+02 6.18303305e+01 -1.71352319e-03 -1.01823932e-02 5.24651895e-02 8.09241828e+00 | + | |
| - | 2.54408601e+02 6.16153978e+01 -6.02304403e-03 -9.01833893e-03 5.38752057e-02 8.07611965e+00 | + | |
| - | Type a message & press enter to stop AutoPointing... | + | |
| - | Continuing... | + | |
| - | Selected source is 3C353 | + | |
| - | 3C353 - X-band | + | |
| - | 6.87293690e+01 2.27332023e+01 -2.35926560e-03 -2.64216019e-02 -5.39766563e+02 -1.36228380e+05 3360 | + | |
| - | 6.84840694e+01 2.29447284e+01 -1.24883255e-02 -4.65807716e-03 3.30921926e-02 8.45462290e+00 3403 | + | |
| - | 6.82383931e+01 2.31555810e+01 3.51911062e-03 -2.47805389e-02 3.26169632e-02 8.47415431e+00 3460 | + | |
| - | 3C353 - S-band | + | |
| - | 6.79819576e+01 2.33745982e+01 3.13166250e-02 -2.27306091e-02 -1.24692372e+01 -1.25976266e+03 4016 | + | |
| - | 6.77250691e+01 2.35929034e+01 -3.30836441e-02 -1.97442791e-02 2.18987395e-01 2.15648178e+01 3915 | + | |
| - | 6.74621249e+01 2.38152119e+01 -1.33919869e-02 -8.66837313e-02 2.09943492e-01 2.13562383e+01 4044 | + | |
| - | Type a message & press enter to stop AutoPointing... | + | |
| - | stop | + | |
| - | Continuing... | + | |
| - | oper@pcfshb:~$ | + | |
| - | </file> | + | |
| - | + | ||
| - | After each source title, the three outputs of each pointing observation are reported. The columns are Azimuth, Elevation, Azimuth offset, Elevation offset, source amplitude, Tsys. The units are degrees for azimuth and elevation and both the source amplitude & Tsys are reported in units of the CAL. Total pointing offsets should generally be less than ~0.02 degrees. Total pointing offsets greater than 0.04 are considered to be critical and require immediate investigation. Pointing offsets less than this should be dealt with as soon as possible after the observation. | + | |
| - | For sources which are recognised as calibrators (currently Virgo, Hydra, 3C348 & 3C353) there is a seventh column which reports the SEFD, estimated from the source amplitude. For these sources, there will be a second set of observations performed using the S-band system. The pointing offsets from these observations are best disregarded. | ||
/home/www/auscope/opswiki/data/attic/operations/documentation.test_antenna.1354573352.txt.gz · Last modified: 2012/12/03 22:22 (external edit)
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