The ``observer'' workstation in the control room is used to connect to the vxWorks system and can also be used to monitor data using ANALYZ.
On arrival in the Control Room, introduce yourself to the telescope operator, and tell him which receiver you require. He will ensure that the turret in the Gregorian enclosure is rotated to place that receiver at the focus. Once in place, request the operator to turn off the video and the turret drive, as these are known sources of RFI in the Gregorian enclosure.
The numbered items in the sequence below need to be executed in order, though some of them may be placed in the general setup file to speed operations along:
Lines with vw% are entered in the right-hand (vxWorks) datataking
window. Lines with observer% are entered in the left-hand (Unix)
window. (checklist details are on the following pages)
*** Don't invoke any of these commands until the operator has told you
that you have control of the telescope.
1. login to "observer" as dtusr .. ask the operator for the passwd.
2. observer% datataking cor .. in the right-hand window
- vw% gousr .. move to /share/obs4/usr directory
- vw% cd a9999 .. move to the proposal subdirectory
3. vw% source a9999.su .. execute the general setupfile
4.*vw% pnt tur q .. check that turret is in position
5.*vw% trkinit lb(or lbw or...) .. to start the L-narrow pointing model
6.*vw% pnt mode stow 4 .. send carriage house to stow position
7.*vw% adjpwrif1 .. adjust upstairs IF/LO power levels
8.*vw% if1mp .. check upstairs power levels
9.*vw% coradjpwr .. adjust correlator power levels
10. vw% qdata .. check the online data file is empty
. vw% mvdata junk .. if not, move any the old file to junk
11. observer% gousr;cd a9999 .. in l.h. window, move to subdirectory
12. observer% monpnt .. start a pointing monitor there
13. observer% analyz .. start ANALYZ with register length
8192 and about 200 sto/rcl registers.
14. check on the spectrum analyzer that the bandpass looks ok.
* Items may be placed within the general setup file. If so, the starred
commands do no need to be re-typed.
If your source has appreciable power (>20K, or 2Jy at L-band)
you should execute steps 7-9 again when ON source. This is NOT
necessary for weak sources.
15. At this point in the sequence you are ready to track sources and
take data, e.g.
vw% dosrc IRC+10420
---> AFTER observing be sure to execute:
vw% mvdata a9999 .. save the data to off-line storage
vw% exit .. terminate the correlator program
The command "mvdata" saves and renames the on-line data file (corfile)
to corfile.ddmonyy.a9999.n, where n increments by one each time you use
mvdata in a single 24 hour day.
DETAILED NOTES ON THE SEQUENCE of steps 1 - 14
--------------
1. Login to the ``observer'' Workstation
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observer% datataking corThis executes a script that outputs the following:
spawn rsh cor mcpProg vw% source $baseTcl/Setups/setups.cor vw% init vw% setup vw% io tapeIo Off discIo Off vw% tape stat mcpTapeCmd: err 0xd0003 .... ignore this error, there is no tape.... vw% online.. exit cmd to quit. vw%The
vw% prompt comes from vxWorks.
vw% source a9999.su ;#when in subdirectory a9999
vw%source /share/obs4/usr/a9999/a9999.su ;#otherwise
pnt tur q queries the turret position and then returns
the time, position (deg) and status of the turret to the monitor screen
(cf Section 1.6.4 for the various receiver positions)
trkint lb instructs the pointing program to use the
Narrow-band L-band pointing model and to start tracking the
current azimuth, zenith angle. Replace ``lb'' with the code
appropriate to your receiver - (cf Section 1.6.4)
pnt mode stow 4. Do not execute this command until the
operator has told you that you have control of the telescope.
adjpwrif1 adjusts the upstairs
attenuators to give -40db within 1 or 2 db (if it can).
if1mp returns the power levels read by the power meter at
the input to the fiber optic transmitter. This level should be between
-50 and -20 db (typically -40 db). The two number returned are for
polA and polB, e.g.
vw% if1mp
-40.70 -41.07
coradjpwr adjusts the correlator attenuators to give an optimal
power level for the requested sampling mode. These attenuators have a
range of 0-15 db.
vw% coradjpwr
sbc pwrRatio attn (range 0-15)
1 1.08 8
2 1.00 5
3 1.07 8
4 1.12 4
5 1.00 7
6 0.93 3
7 1.00 8
8 1.01 3
The pwrRatio is the measured/optimum power level (linear scale), and
should be of order unity. The sub-correlator order (sbc) is board 1,
board 2, board 3, etc.. If you are using both polarizations on a
correlator board then sbc 1 = polA brd1, sbc 2 = polB brd1, sbc 3 =
polA brd2, etc.
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10. Check for any Old Data Files
--------------
qdata queries the size of the current data file. If it is not 0,
you should execute:-
vw%mvdata junk
this renames the current file to corfile.ddmmmyy.junk.n .. Whoever
it belonged to can then worry about where it went. If you don't do this,
you overwrite whatever was in that file (ok for you but it
may upset some forgetful people).
--------------
11. In the Left-hand Solaris Window move to the proposal Sub-Directory
--------------
gousr is an alias that changes directory to
/share/obs4/usr and then prints out its subdirectories. You
need to cd to your proposal subdirectory. ANALYZ will run from
there. (eg: gousr; cd a9999).
--------------
12. Start the Pointing Monitor on ``observer''
--------------
The pointing monitor should be started from the left-hand window:-
observer%monpnt
--------------
If you prepared ANALYZ ahead of time, following section II.5, simply start ANALYZ;
observer%analyz -u a9999
To start ANALYZ for the first time in this location follow the
instructions found in the Spectral Line User's manual.
(For an alternate set of commands and libraries see Appendix A.6.)
--------------
14. Check on the Spectrum Analyzer that the Bandpass looks OK.
--------------
Plug the spectrum analyzer cable into rack 4 IF output (3rd chassis from the top). on the spectrum analyzer:
freq
750
MHz
.. then
span
500
MHz
You will see a flipped spectrum. For the L-band narrow system,
there is a sharp cutoff at 1370 MHz (if the waveguide filter is
installed). Move the cable to rack 6 IF output (polB) and check
that it looks the same. Appendix ??? has a description of the
downstairs racks.
--------------
15. Taking Data:
--------------
You can check the if1 setup parameters, including cal size and lbfb setting,
vw% if1
You can examine the frequency settings, etc via
vw% if2
You can check that the correlator has the values you requested:-
vw% cor
If the correlator returns attenuation values too close to the
extremes, you can override the initial values, and set in NdB
at if2, via
vw% adjpwrif2 -e N
You can check that the disk is turned on for writing
data by issuing
vw% io
Should it not be on, issue ``disc on'' to remedy. This has been
known to occur if step 13 was executed out of sequence. The
disc can be off, even though the correlator is running.
If you wish to send give the telescope coordinates which are not in your src.list file, you can type
set ra hhmmss.s set dec hhmmss
To read a source from your source list, type
srcget [src name]
To send the telescope to the current coordinates, type
pnt tr $ra $dec [for J2000 coordinates] pnt tr $ra $dec -cb [for B1950 coordinates]
To stop the telescope from slewing, use
pnt tr hold
To send the telescope to the coordinates, type
pnt tr send
Finally, to stop a procedure (when all else fails), hit control-c.
There are a number of standard datataking routines, depending on what you want to do: (onoffcb, onoffcj, dopairb, dopairj, hexmap2b, etc.) These will usually be customized inside your procedure file into two or three generally executed procedures, such as ``dosrc'' and ``go'':-
dosrc IRC+10420 n ;select the source from your source-list file
;executing the pointing pattern and data
;acquisition sequence n times
It is also simple to execute a file of observing procedures, by
entering the sequence to be followed into a file, say a9999.cmd, and
then sourcing it:-
vw% source a9999.cmd
An example of file (a9999.cmd) of sequential actions is;
#################################################################### #Begin with a strong source to confirm setup # dosrc IRC+10420 1 1 # #Now proceed to pull a weak source out of the noise by 5 onoff pairs # dosrc 18095+2704 5 # #now onto a second source # dosrc 19386+0155 5 # #fin ####################################################################