You should only observe without the Gui if you truly necessary. The gui exists to make both your life, and the life of you Friend of the Telescope (and most liekly the life of Phil Perrilat) much easier, as well as insuring that your observations go smoothly. Please use it.
A. Gui-Free Observing: Spectral-Line Checklist
If you were to observe for proposal number a9999, upon arrival at the Observatory you will be provided with:
To PREPARE to take data execute 1-13 in sequence:
1) login to "observer" as dtusr .. ask the operator for the password
2) observer% datataking cor .. in the right-hand window
- vw% gousr .. move to /share/obs4/usr subdirectory
- vw% cd a9999 .. move on to your program subdirectory
3) vw% source a9999.su .. source your program's setup file
4) *vw% pnt tur q .. check turret position for your Rx
5) *vw% trkinit lb (or lbw or ..) .. initiate pointing model for your Rx
6) *vw% pnt mode stow 4 .. stow the carriage house
7) *vw% adjpwrif1 .. adjust upstairs IF/LO power levels
8) *vw% if1mp .. check upstairs power levels (-40db)
9) *vw% coradjpwr .. adjust correlator pwr levels (3-13db)
10) vw% qdata .. is current online data file empty?
- vw% mvdata junk .. if not, save its content to junk
11) observer% gousr;cd a9999 .. to "observer" directory in l.h. window
12) observer% monpnt .. start pointing monitor in l.h. window
13) observer% analyz .. start ANALYZ [-u a9999 -l 8192 -n 200]
14) check that the receiver bandpass looks OK on the spectrum analyzer
---> To move to your source and start taking data with the correlator,
type something like:
15) vw% dosrc IRC+10420
---> AFTER your observing run finishes execute:--
16) vw% mvdata a9999 .. to move your data into off-line storage
17) vw% exit .. to terminate the correlator program
Starred items (5-9) may be accomplished by making them entries in your setup file.
To CHECK data on-line, you will type into ANALYZ something after the fashion:-
corget .. to load and display a single scan of data
do .. to process data, such as an ON-OFF pair
ss1;pv .. move to the first sbc, & plot v's velocity
sh1;pv .. shift to next sbc, & plot v's velocity
The following sections explain these items, and provide information on
some of the many options available.
B. Gui-Free Observing: Introduction
Your proposal is given a project number on receipt by the Observatory. For purposes of illustration let this be a9999
Upon arrival at the Observatory you will be provided with:
BEFORE you get to the telescope you need:
---> src.list
---> a9999.su
that customizes the system environment for your project, and
in particular points to YOUR source list, log-file, procedures file,
and correlator setup file. In addition it invokes your receiver,
invokes the IF/LO setup, and sets the frequencies you want to observe in
each of the four independent sub-correlators. It may also place frontend
filters into your signal path, and change the default size of the gain cal.
---> adammcp.????.0
or
---> a9999.proc
which looks up the position and velocity of the target in your source list,
and executes your choice of pointing patterns, datataking, and cal sequences
vw% dosrc IRC+10420 ;move to and take data on the named
target from your source list
C. Gui-Free Observing: Preparation of Observing Files
C.1. The Source List File The source list file can be prepared ahead of time with any text editor. Its format is illustrated by the following example, in which # precedes a comment, and spaces separate items:-
################################################################### # Dated 13 February 1999 # #For BW 7 (=0.7825 MHz) on this group # # IRAS RA(1950) DEC(1950) vel(LSR ) 18455+0448 184533.9 044806 b 34.1 #Ben's 1612 MHz variable 18560+0638 185603.8 063848 b 19.8 #OH39.7+1.5 #high latitude sources with no prior mainline observation #FOR a search BW 5 (= 3.125 MHz) on these # 12363+1404 123620.4 140443 b 0.0 13014+0720 130124.2 072012 b 0.0 #last of LRS 2n sources 13054+2353 130528.0 235330 b 0.0 #continuum calibration source (epoch 2000) J1600+042 160002.5 041258 j 0.0 # ###################################################################where,
, 
),
are supported.) Required.
The general set-up file, (e.g. a9999.su), will have a general structure similar to the following example, which is a suitable template for editing to your needs This file can execute ``always-to-be-executed'' setup commands for your project:-
####################################################################### #Setup for observing 4 OH lines at bw 7 with wide-band L-band Rx (== 5) # #Section A: attach requisite files, set your observing (rest) frequencies # set proj a9999 ;#set your project id gousr cd $proj ;#ensure you are in your subdirectory logOpen "$proj.log" ;#open a log file for your session srcfile src.list ;#attach your source list for the session set corfile a9999.corsu ;#identify your correlator setup file (a.k.a. a9999.corsu) source $proj.proc ;#attach your procedures file to the session # set rfcfr 1660.0 ;#identify the central frequency of first IF set sbfrq1 1612.2310 ;#set central frequency of first sub-correlator set sbfrq2 1665.4018 ;#ditto for subcorrelator 2 set sbfrq3 1667.3590 ;#ditto for sbc 3 set sbfrq4 1720.5300 ;#ditto for sbc 4 # # #Section B: initiate telescope control, Rx, & signal path components # setupall lbw $rfcfr ;#setup the telescope, turret, and iflo lbfb 4 ;#set L-band filter for OH lines [optional!] setcal hcal ;#change default gain cal to large [optional] # #Section C: Sub-band and Doppler frequency setup for the IF/LO system # dopsetfrq $rfcfr $sbfrq1 $sbfrq2 $sbfrq3 $sbfrq4 dopsetsball ;#to request doppler freq. shifts for all sbc dopsetvel 0.0 lsr ;#defines lsr as velocity coordinate system dopsetdoit ;#sets synthesiser vals (to measure power levs) # #Section D: adjust IF/LO power levels and then configure the correlator # corsetup $corfile ;#configure the correlator # coradjpwr ;#adjust power levels to the subcorrelators adjpwrif1 adjpwrif1 ;#adjust power level into fiber-optic cable if1mp ;#measure its power level # # END of file ;#subsequent commands can be interactive # requests #######################################################################The general setup file has 4 sections (A-D) which contain most proposal specific and computer settable instructions for your operations (the procedure file has NOW hopefully been stripped of specific proposal file names, frequencies, etc., to stand on its own as a set of general operational control sequences).
setupall ``name''where ``name'' identifies the receiver you wish to use. Table 2 lists these for the currently available receivers. Each receiver has a unique position on a turret, which on rotation brings it to the focus of the tertiary. And each has an associated telescope pointing model. Calling setupall insures all the corect parameters are set.
See Table 1 in the Spectral Line User's Manual for frequency ranges, measured sensitivity (K/Jy) and system temperature of each receiver.
If you are using the L-band wide receiver, you may need a filter in the signal path to block very strong RFI from your bandpass. Note that more than one filter can be used, but you should be sure NOT to use ovserlapping filters as this will cause a ripple in your bandpass.
Filters are invoked via the command ``lbfb 
'', where the
number is given in the table below.
You may wish to check the recent RFI environment around your target frequency. The results of observatory monitoring are available in the white ``RFI'' notebook in the control room. You can also quickly observe the L-band by using the X111 procedures which the telescope operator has available. (see the RFI Manual).
The default gain calibration for the L-band systems is a high (30% of Tsys) noise-diode ``cal''. To select the low cal, which has an intensity of a few percent of Tsys, include the line
setcal hcalOther options are:
| ``setcal'' code | Description |
| lcal | low ncorrelated cal. diodes A,B straight through |
| hcal | high uncorrelated cal. diodes A,B straight through |
| lxcal | low uncorrelated cal. diodes A,B with crossover |
| hxcal | high uncorrelated cal. diodes A,B with crossover |
| l90cal | low correlated cal with 90 deg phase shift. diode B |
| h90cal | high correlated cal with 90 deg phase shift. diode B |
| lcorcal | low correlated cal with 0 deg phase shift. diode A |
| hcorcal | high correlated cal with 0 deg phase shift. diode A |
The polarization state of the signal available from the wide-band L-band system is set by the hardwired inclusion or exclusion of a hybrid after the cryogenic stage. When this is electrically switchable, a9999.su should assert the polarization required. At present you need to consult the operator as to which polarization is in effect, and see that it is consistent with what YOU require. Switching the hybrid in/out is a one-hour task for the receiver engineer - best arranged with notice of requirement, by your telescope friend.
Section C of a9999.su arranges the observing frequencies for the (4) sbc and whether these are all to be individually doppler adjusted (appropriate for observing differing spectral lines), or whether the frequencies are to be set as offsets from a single line (as with redshifted HI searches).
For redshifted HI searches replace ``dopsetsball'' with ``dopsetrfonly'', ``dopsetfrq'' with ``dopsetoff'', and edit out ``lsr''.
Section D of a9999.su executes the automated adjustment of signal power levels. The results of this need to be checked.
C.3. The Correlator Set-Up File
This file provides the master control program (mcp) with the instructions to configure the correlator for your specific needs. Customizable options include the bandwidth of each sub correlator, the resolution of data from it, and its observing mode (i.e. nine-level, three-level and/or double-Nyquist sampled, etc.). Two ways of creating your correlator setup file are:
The correlator is composed of four independent boards, each a
full correlator in its own right. One board can observe both
polarizations, or just one of the two available from the chosen
receiver, at a bandwidth and resolution that is set
independently for each board. The signal may be three-level,
three-level interleaved, or nine-level sampled. At bandwidths
of 12.5 MHz or less, the signal to noise from three-level
spectra can be improved by oversampling (i.e. using
double-Nyquist sampling). The choice of any of these
configurations is set by the ``lagsam'' variable in
Table 5 , which is specified for each correlator
board as an argument to the cor_lagc command.
| ``lagsam'' | Configuration | MaxBW | sbc/Pol | Boards | Lags/sbc |
| per sbc | used | best resn at 1420 MHz | |||
| 0 | 9-level, A pol. | 25 MHz | 2 | 4 | 2048/(2.6 km/s) |
| 1 | 9-level, B pol. | 25 MHz | 2 | 4 | 2048/(2.6 km/s) |
| 2 | DON'T USE | - | - | - | - |
| 3 | DON'T USE | - | - | - | - |
| 4 | DON'T USE | - | - | - | - |
| 5 | 3-level A & B pol. | 25 MHz | 4 | 4 | 2048/(2.6 km/s) |
| 6 | 3-level interleav. A | 50 MHz | 2 | 4 | 4096/(2.6 km/s) |
| 7 | 3-level interleav. B | 50 MHz | 2 | 4 | 4096/(2.6 km/s) |
| 8 | 3-level interl. A & B | 50 MHz | 4 | 4 | 2048/(5.2 km/s) |
| 9 | 9-level A & B pol. | 25 MHz | 4 | 4 | 1024/(5.2 km/s) |
| 10 | 3-level polarization | 25 MHz | 4 | 4 | 2048/(2.6 km/s) |
9-level operation achieves 98% of the signal-to-noise of analog correlation whereas 3-level sampling achieves 81%. One advantage of 9-level sampling is to limit the effects of RFI (usually) to just a few channels.
The bw code number (cor_bwnum) corresponds to 50/2
MHz,
where n can take values from 1 to 9, which correspond to bandwidths
in the range 50 - 0.195 MHz. The frequency resolution is then the
bandwidth/(number of channels).
The correlator has many more adjustable parameters, such as its truncation to fewer boards, writing out the ACF, or the uncorrected ACF, rather than the FFT, changing the frequency of spectral dumps, and changing the integration time, to name a few.
####################################################################### #This correlator set-up file uses all four boards, with the following config: #Board 6: A polarization, 2048 channels, 12.5 MHz bandwidth #Board 7: B polarization, 2048 channels, 12.5 MHz bandwidth #Board 8: A polarization, 2048 channels, 6.25 MHz bandwidth #Board 9: B polarization, 2048 channels, 6.25 MHz bandwidth # set estart 1 set dumplength 50000000 set lagsam "0 1 0 1 " set lags "2048 2048 2048 2048 " set icyc 1 set bandwd "4 4 3 3 " set corbrds "6 7 8 9 " # mcp setup corProg@cor " cor_lagc $lagsam cor_dblnyquist f cor_bwnum $bandwd cor_lagspersbc $lags cor_extstart $estart cor_adjpwr FALSE cor_dmplen $dumplength cor_chiptestmode FALSE cor_dmpsperinteg $icyc cor_dataformat 3 3 3 3 cor_rdpowcntr TRUE cor_relbitshift 0 cor_rdtotcnts FALSE cor_enablanking FALSE cor_brdlist $corbrds" # #[CAUTION: if a file like this is edited, preserve the required " marks # on its first and last noncommented lines] #######################################################################
C.4. The ``Project Procedures File''
The Tcl-language observing procedures are usually placed in a procedure file named (say) a9999.proc. This file is identified to the system via the execution of
source a9999.procThe Project Procedures File should contain procedures
-->dosrc
-->onoffcb, onoffc (patterns where the
OFF retraces the path of the ON across the
dish exactly using respectively 1950 and 2000
epoch),
-->src,
--> calsrc
--> pnt8
-->map (whether the grid
is in RA-DEC, or -, or Az-El,
etc)
NOTE: At the present stage of operation, telescope users are strongly advised to consult their telescope friend well in advance of arrival, so that your pointing and data acquisition needs are well understood.
D. Gui-Free Observing: At The Telescope