Owen's Notes

Remote Login (23 March 2020)

The computers can be accessed remotely using SSH and VNC. Since I use Linux (Ubuntu) these instruction are for that OS.

To VNC into Helios using

Update Antenna Pointing (17 March 2020)

Access the Pipeline Computer.

From the terminal, start ipython:

ipython --pylab

Import the calibration and Time libraries:

import calibration as cal

from util import Time

Load up the solar pointing scans for a given date and time.

x,y,qual=cal.solpntanal(Time('2020-03-17 18:30'))

The above command will load the scans from the 17 March 2020 18:30 UT.

To view the beam widths as a function of frequency for each antenna and polarisation:

cal.sp_bsize(x,y)

An example of the X-beam widths for each antenna

An example of the Y-beam widths for each antenna

To obtain the pointing offsets:

xoff,yoff,dx,dy=cal.sp_offsets(x,y)

This will display the offsets for each antenna and feed. Ideally the offsets should be at zero. If particular antennas significantly deviate from zero then a correction can be made.

For example, the following command will adjust the pointing offsets for antennas 6 to 8, 10 and 13:

cal.offsets2ants(Time('2020-03-17 18:30'),xoff,yoff,antst='ant6 ant7 ant8 ant10 ant13')

The newer antennas with the alt-az drives that have had tracking updated will need to be rebooted. From the Schedule Window issue the commands:

reboot 1 ant6-8

tracktable sun_tab.radec 1 ant6-8

track ant6-8

The antenna pointing adjustment is typically performed once per month.

Helios Displays

The Schedule window show the currently running schedule as shown below.

The left side of the window shows each of the scripts that is to be run. The orange bar shows the task that is currently being run.

The right side of the window shows each command that is to be run in the current script.

At the bottom of the window are a series of buttons. The STOP button will stop at the current script. Once stopped, the remaining buttons will become active.