Preparing Schedules for LBA observations
For most LBA experiments, you just need to run either
slogit.lbacd.v3.sh (in the observer home directory on newsmerd) to download and correctly drudg an experiment. The script will parse the VEX file for frequency and mode information, drudg accordingly and then add some extra procedures to automatically set up LOs (via the
sched_initi procedure which is called on the start of the schedule). This works quite reliably, about the only thing to watch for is that often in the
sched_initi procedure the script seems to select
sy=/home/oper/rr.sh & for dual polariation experiments. Check on the LBA wiki and if it is a dual pol experiment, change this line to be
For LBA experiments on Katherine and Yarragdee run
slogit.lbayg.sh (again in the observer home directory on newsmerd).
older info below
First you need to collect the latest vex files from the ATNF ftp servers. The easiest way of doing this is using the
slogit.lba.sh script on newsmerd (for hobart experiments) and
slogit.lbacd.sh on newsmerd (for Ceduna experiments). Log in to newsmerd as observer and run
After that, just follow the prompts and it will download the vex files, transfer them to hobart, drudg it and put the snp and prc files in the correct locations. The only tricky part is when it will prompt you for a systemp procedure. A number of readymade ones are available and are listed below. The number is the frequency (for VSOP mode) and are dual-pol unless otherwise indicated. The CAL values were confirmed in the previous LBA session. The
systempho.prc file has dummy values of 1000 Jy per CAL inserted in the systemp procedure but is otherwise complete. Use this if you need to measure the CAL height before the run.
If the slogit.lba.sh script fails OR if the experiment has some unusual configuration (such as Mark5A recording), then you will have to do the process by hand. First, move to the
/usr2/sched/ directory on hobart and then connect to the ATNF ftp server by
If you have an ATNF account, use that to log in or just use anonymous. Go to the experiment directory and download the skd file by
Replace v252, v252i with the appropriate experiment codes. The fringe-check schedules are located in
/pub/people/vlbi/fringe-checks/vc071/ (for vc071).
Once the files are downloaded, exit ftp. Next run
drudg v252i.vex on hobart and select the station code that you’re preparing (ho or cd). For disk-based experiments, you will need to reset the equipment as it expects the S2 recorders by default. For Ceduna, enter
11 <Ret> 1 1 1 1 <Ret> to select no rack, no recorder. For Hobart, enter
11 <Ret> 7 1 1 1 <Ret> to select mk4 rack, no recorder. For a Mk5A experiment, use
11 <Ret> 7 10 1 1. Next, make the .prc files with
12 <Ret> . Make the .snp file with
3 <Ret> and print a copy with
5 <Ret> . If you need to process another .skd file, select
8 <Ret> , enter the experiment code and repeat the process. Otherwise, quit drudg with
0 <Ret> .
All that needs to be done now is to move the .prc files to /usr2/proc, and to complete them with the systemp, preob, midod and postob routines. The easiest way of doing this is to go to /usr2/proc and append
systempho.prc onto the end of the files and edit the cal values. You can do this with the command
cat systempho.prc >> v252iho.prc
The added section should look like the example below. A word of warning, do not try to copy & paste these from the wiki! The wiki formatting causes all kinds of quiet errors in the procedures.
define systemp 08331095950x
“tsys1 are sefd (i.e. in jy) for recorded channels 1
sy=/usr2/st/bin/tsys -f 1000,1000 -s -i 0 -n 2
define sefd 000000000000
define midob 08331100004x
sy=run setcl adapt &
define preob 08331095950x
define postob 08331105500x
define systemp 08221005950x
sy=/usr2/st/bin/tsys -f 105,122 -s -n 2 -i 2 rakbus
define preob 08221005950
define midob 08221010004
define postob 08221010940
define ready 00000000000x
You’ll need to replace the values after
sy=/usr2/st/bin/tsys -f with the CAL values (in Jy) for the first and second channels into the frequency translator. By default, these have been set to 1000. If the experiment is single-polarization at Hobart, it’s easiest to just add the same value twice. At Ceduna, only include one value and change
-n 2 to
-n 1. Make sure that the first channel is connected to the first programmable attenuator and SLD.
If you need to control the SMLs within the schedule (e.g. for V255 or V490 experiments) then the bbcv255.prc (and bbccdv255.prc for Ceduna) show how this can be done. Append these to the end of the experiment .prc file and edit the LO settings as is appropriate for your experiment.
cat bbcv255.prc >> v252iho.prc