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operations:documentation.test_antenna

Antenna Checks

At this stage the antenna should still be in the stow position (Az = 1, El = 88).

Check antenna pad

Before moving the antenna, check that the area surrounding it is clear of obstructions. This is best done via the live web cameras so that you can be sure the image is current. The username is observer and the password is the usual one:

If you're not seeing a live image of the antenna or if you think there is obstructing it, DO NOT move it!

If you need to power cycle a web cam (to try and ressurect it), this can be done for Katherine and Yarragadee through their internet power switches (username is admin, password is the PCFS root password).

Click on the “Boot” radio button next to the device you want to power-cycle, which is “Camera”, and click on Apply. Be very careful that you boot the right device!

Generator Status

At Hobart and Katherine you can check the status of the backup generator via the System Monitor interface. The default mode is “In Auto, off” which means it's ready to turn on if there's a power failure but it's currently switched off. If it's in any other state, query it with the On Call person.

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 CLOCK INITIALIZED and SNTP SERVER OK with green backgrounds. If this doesn't look right, consult the On Call person.

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. Call the local support person at the site for assistance.

Antenna pointing check

In the field system:

proc=point
initp

Then choose a source from /usr2/proc/point.prc (e.g. 1618m49, hydra, virgoa, etc). (The monan display can be started if you want to check the sidereal time.) Sources to choose from:

Source     RA             Dec
pictora    05 19 49.7     -45 46 44
1921m293   19 24 51       -29 14 30
0857m43    08 59 27.1     -43 45 09
eso212     09 24 24.2     -51 59 29
1618m49    16 22 12       -50 05 51
0521m365   05 22 58       -36 27 31
virgoa      12 30 49.449    12 23 28.17

Just type in the name of the source you want. e.g.:

1921m293

When the antenna gets on source, start the pointing check:

fivept

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 Fivept Output: What does it mean? but briefly, you should see something like this:

                                    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 

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.

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).

A SEFD check can be made using the new pointing offsets with a

onoff

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.

Zero offsets with

azeloff=0d,0d

(make sure there is no space between the 0d and 0d)

And revert to the nominal DBBC Conditioning Module target power levels with a

proc=<experimentcode><station>
setupsx
/home/www/auscope/opswiki/data/pages/operations/documentation.test_antenna.txt · Last modified: 2016/07/04 16:05 by Jesse Swan