! Example sched input file for VLBA observations at 3mm. ! WARNING - this file uses a setup appropriate for MARK5A ! recordings which is very low bit rate compared to what ! is now normal. The RDBE_DDC can do it, but you probably ! want more bandwidth. eg3mmb.key and eg3mm_rd2.key show ! 2 Gbps setups with the DDC and PFB. ! This example differs from the other 3mm examples mainly ! because it explicitly sets the reference pointing scans ! rather than using the automatic insertion of such scans. ! It also uses a setup similar to that used for the ! observing setup for the pointing scans rather than using ! one of the usual pointing setups used in the other examples. ! That may have once been a good idea, but is no longer ! really needed. ! Original 2000aug08 Craig Walker and Vivek Dhawan ! Modified 10oct2000 RCW for better reference pointing. ! Modified for RDBE Mar. 24, 2014. RCW. ! ========================================================== ! ================= Cover Information ==================== ! ========================================================== version = 1 expt = '3mm observing' expcode = eg3mma piname = 'Craig Walker' address1 = 'National Radio Astronomy Observatory' address2 = 'P. O. Box O' address3 = 'Socorro, New Mexico, 87801' address4 = ' U.S.A. ' phone = '505 835 7247 ' obsphone = '505 835 7247 ' email = cwalker@nrao.edu fax = '505 835 7027 ' obsmode = '6cm 128-4-2 ' obstype = VLBA note1 = 'Will use reference pointing.' ! ========================================================== ! ============== Correlator Information ================== ! ========================================================== correl = Socorro coravg = 1.0 corchan = 64 cornant = 4 corpol = on corwtfn = uniform corsrcs = standard cortape = DAT corship1 = 'Craig Walker' corship2 = 'P. O. Box O' corship3 = 'Socorro NM 87801' ! ========================================================== ! ================== Program control ===================== ! ========================================================== ! Normally SCHED will not overwrite preexisting files. ! If you want this protection, comment this following line. overwrit ! ========================================================== ! ======= Standard Source and Station Catalogs ============ ! ========================================================== stafile = $SCHED/catalogs/stations_RDBE.dat srcfile = $SCHED/catalogs/sources.vlba freqfile = $SCHED/catalogs/freq_RDBE.dat ! ========================================================== ! ===== Line rest frequencies at 7mm, 3mm and 1.3cm. ===== ! ========================================================== lineinit / lineset='SiO431' restfreq=43122.027, 43122.027 / lineset='SiO862' restfreq=86243.4, 86243.4 / lineset ='H2O' restfreq=22235.08, 22235.08 / endlines / ! ========================================================== ! ================== Source Catalog ===================== ! ========================================================== ! Note that pointing sources can be found in ! $SCHED/sources.pointing. ! The following file is used for the fringe finders. srcfile = $SCHED/catalogs/sources.vlba ! This example uses P-AHSco as a pointing reference source near SgrA ! for observations of SgrA. The reference source is an SiO maser. ! P-RPeg is a maser pointing reference near the fringe finder 3C454.3. ! Note names or calcode may be used to distinguish pointing sources ! The maser sources can be found in $SCHED/catalogs/sources.pointing ! The maser velocity is set for the first channel pair. Other ! channels have offset velocities set to spread the frequencies srccat / source='SgrA' RA=17:45:40.0399 DEC=-29:00:28.137 equinox='J2000' remarks='Galactic center' / source='P-AHSco' RA=17:11:16.98 DEC=-32:19:31.2 equinox=j2000 vel=-7, -7, 100, 100, 200, 200, 300, 300 remarks='sest. many spectra on SEST home page.' / source='P-RPeg' RA=23:06:39.157 DEC=10:32:36.07 equinox=j2000 vel=20., 20., 100, 100, 200, 200, 300, 300 remarks='Baudry + sest' / endcat / ! ========================================================== ! ======================= Setup file ===================== ! ========================================================== ! Note that it is no longer necessary to have the pointing ! setup be similar to the observing setup as long as the ! pointing setup has FORMAT = NONE. Then the formatter is ! not reconfigured. Setup pt7mm.set could be used, although ! a setup similar to the observing setup (without FORMAT=NONE) ! is used in this schedule, which is also ok. ! Strong SiO masers will be used for most of the pointing. setini = v3mm-256-8-2.set / nchan = 8 bits = 2 bbfilter = 8.0 freqref = 86244.25 freqoff = -11.50,-11.50,-3.50,-3.50,4.50,4.50,12.50,12.50 netside = U, U, U, U, U, U, U, U pol = dual / endset / ! ========================================================== ! ================= Initial Scan Information ============= ! ========================================================== year = 2000 month = 7 day = 5 start = 02:03:00 STATIONS = VLBA_FD, VLBA_PT, VLBA_KP, VLBA_LA ! ========================================================== ! =============== A Note on Reference Pointing =========== ! ========================================================== ! Sched now always puts any reference pointing inside the ! scan where it is requested. The VLBA on-line system will not ! begin the pointing sequence until the antenna is on source, ! but if it has to wait more than about 40 seconds, it will ! give up. Therefore, when explicitly specifying reference ! pointing scans, it is good to use dwell, or at least specify ! a gap long enough for the antenna to reach the source. The ! pointing scan should have about 60 seconds of on-source ! time to do the pointing. ! ! This example shows full explicit insertion of reference pointing ! scans. See the other eg3mm examples for use of the automatic ! insertion of scans, or at least automatic conversion of specified ! scans to pointing. ! ========================================================== ! ======================== The Scans ===================== ! ========================================================== ! ! Note that this schedules GAP and DUR. That will not ! be optimal for most cases. Consider using DWELL. pcal=OFF ! No useful PCAL is available at 3 mm. ! Start with a fringe finding scan on 3C273 with reference ! pointing on itself at 7mm (might need to use a line source). ! See the SGRA loop below for details of what each scan is doing. ! BW=0 invokes the setup file bandwidth. Would be needed later in ! schedule, but not strictly necessary here. ! Note if more than one BW is ever set explicitly to a non-zero ! value, those same channels must be set explicitly again next ! time there is a change. It is probably best to either only ! every give one value, or always specify all channels explicitly. source='3C273' setup='$SCHED/setups/v7mm-256-8-2.set' norecord gap=03:00 bw=0 ! Get to source and do pointing peak=1 dur=0:02:00 / setup='v3mm-256-8-2.set' nopeak gap=0 ! Set to 3mm and turn off pointing. record dur=0:10:00 / ! Fringe finding scan. ! Now get to the vicinity of the main program source with a dummy ! (norecord and nopeak) scan. This could be done with a gap in ! the first scan, below, but then that can could not be in the loop. source=SgrA norecord gap=0 dur=0:4:00 / ! MAIN OBSERVING: 3 scans in a loop. ! A: First is for reference pointing. No tape recording. ! Assume slew less than 40 sec and allow time for slew and pointing ! Use a 7mm setup like the 3mm setup to allow step B. ! Otherwise could use the simple peaking setup. ! B: Second helps confirm pointing from an autocorrelation. ! This is not required, but it could be useful to assist calibration. ! If the maser source has a 3mm line, consider looking at that. ! C: Third is the VLBI observing scan. ! BEGIN LOOP group=3 repeat=25 ! Loop through following 3 scans 25 times. ! A: Reference pointing. ! It used to be possible to drop the bandwidth but keep the rest ! of the setup. But the DiFX (and RDBE?) cannot oversample, so ! use a setup with 2 MHz channels. Also use only 4 channels. setup='$SCHED/setups/v7mm-32-4-2.set' source='P-AHSco' ! A nearby strong line source doppler ! Shift frequency for doppler offsets. bw=2 ! Use narrow band so power dominated by line. linena='SiO431' ! Use the 7mm SiO line norecord ! Don't record VLBI data during this scan. peak=1 ! Peak up on this source using channel 1 dur=0:02:00 gap=0 / ! Slew to source and peak up. Assumes short slew. ! B: Get autocorrelation on line source. ! Still do the doppler calculation. Note LO's will change because ! of changed bandwidth. Can check frequencies in sch files. setup='$SCHED/setups/v7mm-256-8-2.set' record ! Record VLBI data during this scan nopeak ! Don't peak. Use preceeding results. Those ! results will be used until the next peak=n scan bw=8 ! Use the same bandwidth as on target. ! Line will be resolved in spectra. Could use bw=0 gap=0:00:00 dur=0:01:00 / ! One minute scan. No slew time. ! C: Now record data on target (continuum in this example) setup='v3mm-256-8-2.set' source=SgrA bw=8 nodop ! No doppler calculations gap=0:0:00 dur=0:10:00 / ! 10 minute recording scan. ! END LOOP ! Fringe finding scan on 3C454.3 with peakup on P-RPeg after slewing ! to P-RPeg. The scan sequence is the same as above with a slew ! scan, a peak scan, a scan to get autocorrelation data, and the ! main observing scan on the 3C454.3. The input is compressed by ! not repeating inputs when not needed and by omitting comments. setup='$SCHED/setups/v7mm-32-4-2.set' norecord source='P-RPeg' doppler bw=2 linename='SiO431' gap=3:00 dur=2:00 peak=1 / setup='$SCHED/setups/v7mm-256-8-2.set' record bw=8 dur=1:00 nopeak gap=0 / bw=8 setup='v3mm-256-8-2.set' source='3C454.3' nodop dur=10:00 /