Handling Beamformed Observations

Scheduling Observations

Observations are typically scheduled using the quicksched.py script found here. This is a python3.6 script that takes in a file with schedule entries in a specified format, and then produces two files to observe the specified sources with the HBAs in mode 5 from subbands 12 to 499. 

By default, the script wakes up 3 minutes forbefore the first (and any STOPSTART) observations to configure the telescope into software level 3. Ensure you consider this time when scheduling observations.

Each entry roughly follows the format

YYYY-MM-DDTHH:MM - YYYY-MM-DDTHH:MM :<TAB>SourceName [RightAscentionRadians, DeclinationRadians, 'COORDINATEBASIS']

These can be chained together to form a schedule that looks like this.

2021-09-20T19:30 - 2021-09-20T20:29 :	J1931+4229 [5.110297162889553, 5.110297162889553, 'J2000']
2021-09-20T20:30 - 2021-09-20T20:49 :	B1951+32_PSR [5.20531221260202, 0.5738302241353217, 'J2000']

In the case that other observations are scheduled using other software and you need to leave a gap, you can add STOPSTART to the end of the line after the gap takes place. Whenever this keyword is detected, the station shuts down after the previous observation, then starts up 3 minutes before the given scheduled observation is meant to begin. As an example, thiese observations will run from 19:27 - 20:29, shut down for an hour, then run again from 21:33 - 21:59 before returning the station to software level 0.

2021-09-20T19:30 - 2021-09-20T19:59 :	J1931+4229 [5.110297162889553, 5.110297162889553, 'J2000']
2021-09-20T20:00 - 2021-09-20T20:29 :	B1951+32_PSR [5.20531221260202, 0.5738302241353217, 'J2000']
2021-09-20T21:33 - 2021-09-20T21:59 :	J1931+4229 [5.110297162889553, 5.110297162889553, 'J2000'] STOPSTART

After running python quicksched.py my_schedule.txt, two files will be created in your directory with the prefixes lcu_script_YYYYMMDD.sh and ucc_script_YYYYMMDD.sh, which will be used to perform and record the observation.

Running Observations

Configuring the LCU 

In order to perform your observation, you will need to transfer the lcu_script_YYYYMMDD.sh script to the LCU. In the case that handover has already been performed, you can simply transfer the script to the station (preferably a sub-directory in ~/local_scripts/) and run it in a screen as a normal bash script.

lcu ~/local_scripts/dmckenna $ screen -S dmckennaObs
lcu ~/local_scripts/dmckenna $ bash lcu_script_YYYYMMDD.sh
< Control a, b to exit > 

Scheduling before local mode

However if we do not yet have the station and the observation will start before you are available for the day, there is a script on the LGC at ~/David/transfer.sh that can take an input and transfer it to the station, then launch a screen and execute the script unattended.

The transfer.sh script depends on the sleepuntil.sh script located in the same folder, if you make a copy of transfer.sh to modify the target directory, be sure to copy sleepuntil.sh to the same folder to ensure it can run.

The transfer.sh script takes 3 inputs: the path of the script to transfer, the date to transfer (as YYYYMMDD) and the time to start trying to transfer (HHMMSS). As an example, to transfer a script for handover occurring at 2022-02-02T08:00:00 the following command could be used to start trying to transfer file 30 minutes prior to handover. In the case that we receive the station early, this will allow for the file to be transferred and station to be configured as soon as possible.

ilofar@LGC ~/David $ tmux new -s transferLCuScript
< enter tmux shell>
ilofar@LGC ~/David $ bash transfer.sh 20220202 073000
< Control d, b to exit >

Recording on UCC1

Given ucc1 should always be available, the script can be transferred to the recording drive and executed as needed. We currently perform all recording on the ucc1_recording2 drive which can be easily accessed via the cdr2 alias on the obs account. After that, you can get the required scripts in the scripts folder, and make a sub-directory for the given source category and perform the observation.

# Connect to ucc1
ilofar@LGC ~ $ ucc1
# Navigate to the recording directory
obs@ucc1 ~ $ cdr2
# Make your recording folder
obs@ucc1 /mnt/ucc1_recording2/data $ mkdir rrats/2022_02_02
# Copy the recording scripts to the folder
obs@ucc1 /mnt/ucc1_recording2/data $ cp ./scripts/* ./rrats/2022_02_02/
# Enter the folder
obs@ucc1 /mnt/ucc1_recording2/data $ cd rrats/2022_02_02
# Add your ucc_script_YYYYMMDD.sh script to the folder via rsync, scp, nano + copypaste, etc

# Open a new tmux shell 
obs@ucc1 /mnt/ucc1_recording2/data/rrats/2022_02_02 $ tmux new -s recording
<attach to tmux shell>
# Run the observing script
obs@ucc1 /mnt/ucc1_recording2/data/rrats/2022_02_02 $ bash ucc_script_YYYYMMDD.sh
# Close the tmux shell after all observation have been completed.

Processing Observations (TODO)