The Arecibo Legacy Fast ALFA (ALFALFA) Survey

A2669 Observing Checklist (for ALFALFA LBW Observations)

WARNING: Version date: Mar 2012

Checklist date:	08 Mar 2012
CIMA version :	"A `smart' version of CIMA (3.1.08 2010-02-01 17:44 "Smart")"

Before observing, be sure to study the background document.

This is a short checklist of the things to do when observing with LBW as part of the ALFALFA followup observations.
Remote observers: see the LBW remote observing checklist (Note: instructions are almost the same as for A2010/ALFA except of course when it comes to the specifics).
It is always a good idea to check with recent observers about their experiences.

Important differences between ALFALFA followup observing with LBW and A2010 drift scan observing with ALFA

New for March 2012: The mode for high velocity sources is slightly modified; you don't need to do anything different but be sure to load up the proper configuration file for your night. See the A2010 schedule page.
We use the same user account (to login, etc), but the observing program name is different. In spring 2012, the observing program is called "A2669". You can navigate, as user a2010, to the observing file directory by typing "a2669obs" in any window.
We use LBW not ALFA. Therefore, there are no waterfall plots, no `quicklook', no FITS files, etc, and the frequency range covered by the bandpass will shift around depending on the observing mode and the heliocentric velocity of the target source.
We use the "interim correlator" not the WAPPs as the spectrometer. The bandwidth is also narrower, and may shift around. We actually record four sets of spectra one of each of the four correlator "boards". Under most conditions, we will actually use only the first two boards; the others are recorded to monitor RFI and to look for sources where a detection is not confirmed. Read about the Spring 2012 observing modes.
We use different software routines to monitor the data. You'll have to follow the instructions; see below!
The observing program consist of a series of 3-minute ON-OFF "pairs", one for each galaxy followed automatically by a CalON/CalOFF sequence which takes 20 seconds; observing each target "pair" takes about 8 minutes plus slew time. Then it's time to look at the resulting spectrum to see if there is a galaxy lurking there!
During each observing block, the observing sequence will be executed by running a command file called "a2669_YYMMDD.cmd", found in the observing directory "/share/obs4/usr/a2669".
Your job includes (a) watching that the telescope does what it is supposed to; (b) making sure the timing of the observations stays roughly on schedule; and (c) making a quick check of the result for each galaxy to see if there is a detection; hence you will have to keep track of what is going on!
The good news is that the observing sequence is executed using a command file. Once you set up the receiver and the correlator and start to run the command file, the observing sequence will run automatically, moving from source to source and running the ON-OFF sequence for each one smoothly (but again, you need to pay attention!).
We do not run TOGS; there is no commensal observing, and so (we presume), no need for a cell phone.

Startup:

Log into OBSERVER2: dtusr (once the previous observer is done). Password is taped to computer (or get it from the operator in advance).
Start CIMA on-line GUI:
- Type cima --X in an available window. Select the desired version of CIMA; this is currently "The 'smart' version of CIMA (3.1.08 2010-02-01 17:44 "Smart")"
- Project Number: a2669 (note: even if you type "A", CIMA will change it to "a" when you click "Line")
- Observer: your name (for entry into operator's log book)
- select Line and Accept
Several other windows will also open: the CIMA log display window and the CIMA observation status window. Leave them open through the night.
The Receiver selection menu will open. Choose Receiver: L-Band Wide and Accept.
Make sure that L-wide shows up in the aostatus monitor. Leave the default options as is:
- Make quick Tsys measurement: No
- Rotate receiver into position: Yes
- Retrack source if selected: Yes
Utilities->Load configuration file
Load the appropriate a2669 configuration file: (There will be more than one; check which one you are supposed to use for the current session).
- Low velocity mode: select a2669_lowvel.conf
- High velocity mode: select a2669_highvelres.conf (New: Mar 12)
They should appear as follows:

Then click Load and apply.
Be patient while the configuration file is applied....

If you cannot find the configuration file (or if only the a2010 files are present), then you entered the wrong project number into the CIMA opening window. You will have to exit CIMA and enter a2669
The CIMA observing menu should pop up; this particular window can also be found via the Observing modes->Spectral line observing button.
This should be set up automatically by the configuration file, so that these items should always be set as follows:

Low velocity mode
High velocity mode

When you have checked things, you can Close this window.
Double check that the receiver IF/LO frequencies have been properly set in the Set-up->Receiver IF/LO selection menu.
This should be set up automatically by the configuration file but you need to know what correlator board configuration you are using, so it's a good idea to check.
There will be one setting per observing session, and two basic settings depending on the frequency range we are using. We normally concentrate on the first two correlator boads (1 and 2); the second set are used for monitoring purposes or to achieve higher resolution according to the observing mode. The first mode, used for the lowest velocity sources (cz < 2000 km/s), uses a fixed 25 MHz bandpass ("topocentric" with no velocity specified) centered at 1420 MHz; the source then will move around in the bandpass, depending on its actual cz. The second mode, dubbed "high velocity", moves the bandpass around according to the velocity of the source. Please be sure you know which one you are using.

Low velocity mode

High velocity mode

When you have checked things, you can Dismiss this window.
- If anything needs to be changed, make sure you have the correct configuration file.
- If this does not help, change the settings manually, then click Apply followed by Accept.
If necessary, double check the Backend control menu
This should be set up automatically by the configuration file, so that these items should always be set as follows:

Low velocity mode

High velocity mode

When you have checked things, you can Dismiss this window.

Double check that the right catalog is loaded in the Set-up->Pointing control menu
This should be set up automatically by the configuration file, so that these items should always be set as follows:

Low velocity mode

High velocity mode

Source: variable (The command file will set the source.)
Catalog: a2669_lowv.cat
Epoch: Equatorial - J2000
Velocity: 0
Frame: Topocentric
Type: velocity(optical)
Offset info: Hide all
System: Main
Az range: Use closest in 0-630 degrees
Track tol: 10 arcseconds

Source: variable (The command file will set the source.)
Catalog: a2669_highv.cat
Epoch: Equatorial - J2000
Velocity: depends on the source
Frame: Heliocentric [Note: At startup this may be initially set to Topocentric. After running command file, recheck and confirm that it has switched to Heliocentric.]
Type: velocity(optical)
Offset info: Hide all
System: Main
Az range: Use closest in 0-630 degrees
Track tol: 10 arcseconds

The Source entry is irrelevant; it will likely be set to the last source from the previous observation.
When you have checked things, you can Dismiss this window.

And, now, you are READY TO GO!
- Click on Command file observing
- Click on Load
- Highlight the correct command file: a2669_YYMMDD.cmd and click Accept
- Click on Run and cross your fingers....

While Observing:

As soon as you start observe, run some immediate quick checks.

Check that the telescope is actually at the correct declination
1. Check the declination displayed in the CIMA observation status window Always check this!
2: Check the "Rslt" line in the monpnt window (the upper right window on the screen below the frequency band monitor). Dec value should stay within a few arcseconds of the drift value. Always check this!

Check the receiver is centered at the right frequency via the "Observer's On-line IF/LO Graphical Display" (the "rxview" command if you are running remotely). NEED TO ADD SCREENSHOTS FOR MAR12 HERE
First line: L-band wide center frequency = 1420.0 MHz (or something else for high velocity mode
2nd line: Receiver filters: 1320 hipass should show 1320 to 1788 MHz
3rd line: IF path: 750 narrowband 60 MHz centered on the center frequency (above)
Bottom table: IF band setup
Note: we use only the first 4 IFs; the other four are not set by us
This table is for low velocity mode

Low velocity mode	High velocity mode
	The above won't be right for highvelres mode... but until we do it, we cannot make a screenshot!

Keep the log file - it is very important to keep an accurate log of what happens, even to note "an uneventful night". Note: log files will be generated in advance for each night's observing. Use the one appropriate for your run.
- To keep the log, ssh to another machine as a2010 and then type a2669obs to get to the A2669 observing directory.
- Find the log file a2669logYYMMDD in /share/obs4/usr/a2669/MONTH12 and edit it using you favorite text editor (vi or pico work well when remote observing; emacs is too slow, unless you use the '-nw' flag to open in a terminal.)
- Check that the setup is what is indicated in the log file, i.e. the CIMA version number and the configuration file.
- Keep track of the approximate LST start, the file number and the ON-source scan number for each pair.
- Check and note any rfi in the observing band. Be especially vigilant for new sources of RFI, and know the expected locations in the band of the "usual suspects". The FAA radar is usually at 1350 MHz (although they sometimes use 1330 MHz, out of our bandpass!). Strong RFI at 1367 and 1382 MHz is due to the Punta Salinas naval base radar, which should not be on during ALFALFA run (see this link.) . If you see this, ask the operator to call Punta Salinas immediately and tell them to turn off their equipment! See observational troubleshooting list for other observing issues.)
- After each pair, take a quick look at the resultant ON-OFF spectrum (see IDL instructions following).
Check the spectrum produced by each ON-OFF pair - Part of your job is to make a quick review of whether the source was detected, at what velocity and also to note the presence of any RFI, bad baselines etc.
Open an IDL session on fusion00 (or aolc1, ...) and run @corinit to compile the corfile utilities, and @lbwinit to compile the LBW observation checking program.
The correlator files are written to /share/olcor/corfile.DDmmmYY.a2669.N
- To check a particular corfile
  checklbw, file='/share/olcor/corfile.DDmmmYY.a2669.N' where N is the number at the end of the corfile
- To show both polarizations of the data:
  checklbw, file=/share/olcor/corfile.DDmmmYY.a2669.N', /pol
- To show spectral data from all four boards (Low velocity mode only)
  checklbw, file=/share/olcor/corfile.DDmmmYY.a2669.N', /all
- To change the number of channels used in smoothing to X (default is 3)
  checklbw, file=/share/olcor/corfile.DDmmmYY.a2669.N', smo=X
- To display the velocity scale in stead of the frequency scale in X
  checklbw, file=/share/olcor/corfile.DDmmmYY.a2669.N', /vel
- To change the yscale
  checklbw, file=/share/olcor/corfile.DDmmmYY.a2669.N', yrange=[-30,50]
When observing in high velocity mode, it is useful to plot boards 3 and 4 separately. To do this, run another idl session and do the following:
- openr, lun, '/share/olcor/corfile.23mar12.a2669.1', /get_lun Use the relevant corfile
- io=corposonoff(lun, b, /han, /scljy) Takes ON-OFF/OFF, scales in Jy; Keeps boards separate; Boards 1&2 are the boards we care about
- bavg=coravg(b, /pol) Averages the two polarizations; Boards 1&2 (separate polarizations) are combined into a single board
- corsmo, bavg, bsm, smo=3 Smooths via boxcar over 3 channels; maybe also want to try 9 channels
- corplot, bsm, brdlist=2, xtitle='Frequency (MHz)',ytitle='Flux (Jy)' Plots the smoothed spectrum; Plot the combined board 3&4 (brdlist=2)
- ver, y_low, y_high Optional: Sets the vertical scale between y_low and y_high. Then execute corplot again.
- close, lun & free_lun, lun Closes the corfile
Check here for a more thorough discussion of what is done in this script. Be sure to record in the log file all useful information about the resultant spectrum, e.g. presence of any RFI, bad baselines etc and whether (or not) the source is detected; if it is, record the approximate central channel and frequency/velocity of the HI line.

Finishing up:

If the command file finishes, then you are done. Usually we include a couple of extra sources at the end, to be done if there is time. If the time allocated for A2669 is up in less than 10 minutes, you should abort the command file.
Exit CIMA normally
Exit the observer2 machine
Exit data monitoring programs "nicely"
Exit IDL (if you were using it)
Exit out of the dataview machine
If remote observing, follow the procedures to close down the VNC connections when you are ready to do that..

After observing...

Here, we're assuming the date is 16 January 2012. Change as necessary.

Open a terminal on an Arecibo machine (i.e. remote.naic.edu):

Copy the log files (CIMA log and observer log) to the web area:
Adjust this as appropriate for your observing date
a2669obs (If this alias fails, then cd /share/obs4/usr/a2669/)
mv a2669.cimalog_20120324 mar12/a2669.cimalog.120324 notice the name format, please; adjust date for today.
mv a2669_120324.cmd mar12
cd mar12
cp a2669.cimalog.120324 /share/a2010/obslogs/mar12/ (Note that the directory is a2010, not a2669!)
cp a2669log120324 /share/a2010/obslogs/mar12/
Move the command file to the the directory with the log files.
This removes it from the list of command files to observe with.
mv a2669_120323.cmd mar12/ (but your date here...)
Determine which corfiles are good, that is, which correspond to completed observations. This includes both detections and non-detections.
This is used to determine which corfiles should be copied over to their final resting place at Cornell.
e.g. if the observations of objects 1-10 were fine, but something failed during 11 and the run was restarted and 45 total objects were observed:
1-10, 12-45
Update the log links file:
aweb (This alias points to /home/a2010/public_html/)
Open loglinks.htm and update the references to the log and CIMA files
Enter the list of corfiles that you made in the previous step.
Go to the loglinks page and check that your update worked.

This page maintained by the members of the Cornell ExtraGalactic Group and their friends, the other members of the ALFALFA observing team
Last modified: Sat Mar 24 16:02:27 2012 by martha