RV162 (Astrometric/Geodetic VLBA-162) 2023 NOV 28 17:30 UTC DOY 332 Notes prepared by David Gordon (USNO) (david.gordon126.civ@us.navy.mil) Special notes for this session: =============================== This session will use the RDBE/DDC/Mark6 system at the VLBA sites, as in previous RV sessions. The X-band frequencies are: 8365.75, 8445.75, 8805.75 and 8925.75 MHz, and spans 560 MHz. The S-band frequencies are: 2212.75, 2242.75, 2282.75 and 2372.75 MHz. The first three S-band channels are in the 2200-2300 MHz range to avoid RFI in Australia. The ending in .75 MHz is necessary at the VLBA stations. Therefore it will not be possible to monitor phase cals using the 10 kHz filters. RV162 will record 8 16-MHz bandwidth channels using 2-bit sampling. The bit rate will be 512 Mbits/sec. The data will be correlated at the VLBA using the VLBA DiFX software correlator. There are 5 non-VLBA stations scheduled - HARTRAO, HOBART26, NYALE13S, ONSALA60 and WETTZELL. These non-VLBA stations should see the "Special operations notes for non-VLBA stations" section below for special instructions. The session begins at 17:30 UTC on DOY 332 for all stations except WETTZELL. First souce is 0235+164 at HARTRAO, NYALE13S and ONSALA60. First source is 3C274 at BR-VLBA, FD-VLBA, HN-VLBA, HOBART26, KP-VLBA, LA-VLBA, MK-VLBA, NL-VLBA, OV-VLBA, PIETOWN and SC-VLBA. First source for WETTZELL is 1327+504 at 18:45:56 UTC after the INT-1 session. To facilitate fringe-finding, there are some long scans on fairly strong sources with many antennas during the schedule. All stations please try to be onsource and recording data for these scans. These scans are: Source Start DURATIONS name yyddd-hhmmss Br Fd Hh Hn Ho Kp La Mk Nl Ns On Ov Pt Sc Wz 3C274 23332-173000| 335 317 315 335 312 323 302 328 320 319 300 | 1803+784 23332-185437| 300 300 313 300 300 300 303 422 392 300 300 318 422| 0235+164 23332-232801| 300 370 300 366 370 369 321 347 370 365 361| We are again using the 'Fill' scheduling option. 'Fill' is run after a schedule is finished in the normal manner. It increases the scan times at stations, when possible, based on how much idle time each station has before its next scan. We used a 'FILL_OFF' margin of 5 seconds. Using 'Fill' on the original schedule, the average observing time increases from 49% to 59%, the average idle time decreases from 20% to 11% and the average scan time increases from 102 seconds to 117 seconds. The observing time increases most at the faster antennas and least at the slower antennas. Purpose ======= This is the sixth of six coordinated astrometric/geodetic sessions in 2023 that use the full 10-station VLBA plus several geodetic stations capable of recording VLBA modes. This year's series is a continuation of the highly successful RDV series begun in 1997. These are now being run under the USNO's VLBA time allocation. Schedule information ==================== This is a new schedule generated by David Gordon at USNO using sked. Schedule file name: rv162.skd. At the IVS Data Center (https://cddis.nasa.gov/archive/vlbi/ivsdata/aux/2023/rv162/ Sked file: rv162.skd Text file: rv162.txt At the VLBA/NRAO: Sked file: rv162.skd Vex file: rv162.vex Text file: rv162.txt Summary file: rv162.sksum This session uses the VLBA stations and 5 IVS stations. The IVS stations are: HARTRAO, HOBART26, NYALE13S, ONSALA60 and WETTZELL. Below is the sked summary. Key: Br=BR-VLBA Fd=FD-VLBA Hh=HARTRAO Hn=HN-VLBA Ho=HOBART26 Kp=KP-VLBA La=LA-VLBA Mk=MK-VLBA Nl=NL-VLBA Ns=NYALE13S On=ONSALA60 Ov=OV-VLBA Pt=PIETOWN Sc=SC-VLBA Wz=WETTZELL Br Fd Hh Hn Ho Kp La Mk Nl Ns On Ov Pt Sc Wz Avg % obs. time: 61 62 47 60 47 62 63 54 62 57 64 61 62 57 64 59 % cal. time: 6 6 3 5 3 6 6 5 6 4 5 6 6 5 5 5 % slew time: 26 26 45 26 34 26 25 26 25 3 23 26 25 27 11 25 % idle time: 6 5 4 8 15 6 6 13 7 35 6 7 6 10 20 11 total # scans: 481 498 264 465 282 498 490 427 478 364 414 491 490 462 402 433 # scans/hour : 20 21 11 19 12 21 20 18 20 15 17 20 20 19 17 18 Avg scan (sec): 109 107 153 112 145 107 111 110 111 134 135 108 110 107 138 119 # data tracks: 16 16 16 16 16 16 16 16 16 16 16 16 16 16 16 # Mk5 tracks: 16 16 16 16 16 16 16 16 16 16 16 16 16 16 16 Total TB(M5): 3.36 3.41 2.58 3.32 2.61 3.42 3.47 3.01 3.41 3.13 3.57 3.38 3.45 3.16 3.56 3.26 # OF OBSERVATIONS BY BASELINE | Br Fd Hh Hn Ho Kp La Mk Nl Ns On Ov Pt Sc Wz Total ------------------------------------------------------------------------------------- Br| 350 2 285 13 357 369 284 340 136 71 388 368 230 64 3257 Fd| 5 301 13 445 462 241 388 90 59 387 460 319 54 3574 Hh| 10 204 1 4 0 6 13 43 0 5 19 68 380 Hn| 2 286 302 166 369 136 104 264 299 361 93 2978 Ho| 18 14 75 9 1 9 20 14 4 25 421 Kp| 450 266 376 85 52 418 456 280 46 3536 La| 244 400 90 61 402 478 304 56 3636 Mk| 204 87 33 307 250 145 24 2326 Nl| 110 74 341 392 340 64 3413 Ns| 233 93 85 95 171 1425 On| 45 57 90 326 1257 Ov| 403 238 44 3350 Pt| 298 52 3617 Sc| 91 2814 Wz| 1178 Number of 2-station scans: 604 Number of 3-station scans: 221 Number of 4-station scans: 81 Number of 5-station scans: 43 Number of 6-station scans: 57 Number of 7-station scans: 82 Number of 8-station scans: 71 Number of 9-station scans: 90 Number of 10-station scans: 116 Number of 11-station scans: 37 Number of 12-station scans: 12 Number of 13-station scans: 7 Number of 14-station scans: 0 Number of 15-station scans: 0 Total number of scans: 1421 Total number of obs: 18581 INTENSIVE BREAKS ================ WETTZELL will be observing the INT-1 session I23332 at the start of RV162 and will join in at ~18:45 UTC. There may also be a USNO/VLBA Intensive also at or near the start of RV162, in which case HN-VLBA and MK-VLBA would miss ~1.5 hours. SOURCE SELECTION ================ There are a total of 80 sources in this session: 60 are from the geodetic source list, 14 are sparsely observed sources being observed only on the VLBA baselines and 6 are sparsely observed far-south sources being observed only on the HARTRAO-HOBART26 baseline. SCHEDULING ALGORITHMS ===================== This schedule uses the "SRCEVN SQRT" mode of Sked. In the absence of any constraints, Sked will preferentially observe strong sources that have high visibility. This mode attempts to smooth out the number of observations per source. RECORDING MODE and FREQUENCIES ============================== The data will be recorded using the following setup: 8 channels, each 16 Mhz bandwidth 1:2 fan-out 32 MHz sample rate 2-bit sampling This recording mode is a modified version of 512-16(RDV). S-band frequencies were modified for the RFI situation in Australia. There is no correlator speed-up factor. The frequency sequence covers 560 MHz at X-band and 160 MHz at S-band using 4 channels in each band. At the VLBA, the X-band uses two LO's in order to fit into the VLBA 512 MHz passband. At the Mark4 stations, the X-band uses both the high and low parts of the geodetic receivers. Because only 8 channels are available when observing with the VLBA/RDBE/DDC systems, a wider spanned bandwidth is not advisable. The following tables list the setup for the VLBA stations and the geodetic stations with DBBC, Mark IV, Mark 5, and VLBA5 back ends. VLBA | HARTRAO Chan Sky Tracks LO IF BBC | LO IF BBC BBC# 1 X 8365.75 2, 4, 6, 8 7600 B 765.75| 8080.0 A1 285.75 3 2 X 8445.75 10,12,14,16 7600 B 845.75| 8080.0 A1 365.75 4 3 X 8805.75 18,20,22,24 9600 D 794.25| 8080.0 B2 725.75 5 4 X 8925.75 26,28,30,32 9600 D 674.25| 8080.0 B2 845.75 6 5 S 2212.75 3, 5, 7, 9 3100 A 887.25| 2020.0 C1 192.75 9 6 S 2242.75 11,13,15,17 3100 A 857.25| 2020.0 C1 222.75 10 7 S 2282.75 19,21,23,25 3100 A 817.25| 2020.0 C1 262.75 13 8 S 2372.75 27,29,31,33 3100 A 727.25| 2020.0 C1 352.75 14 VLBA | ONSALA60, WETTZELL Chan Sky Tracks LO IF BBC | LO IF BBC BBC# 1 X 8365.75 2, 4, 6, 8 7600 B 765.75| 8080.0 A1 285.75 3 2 X 8445.75 10,12,14,16 7600 B 845.75| 8080.0 A1 365.75 4 3 X 8805.75 18,20,22,24 9600 D 794.25| 8080.0 B1 725.75 5 4 X 8925.75 26,28,30,32 9600 D 674.25| 8080.0 B1 845.75 6 5 S 2212.75 3, 5, 7, 9 3100 A 887.25| 2020.0 C1 192.75 9 6 S 2242.75 11,13,15,17 3100 A 857.25| 2020.0 C1 222.75 10 7 S 2282.75 19,21,23,25 3100 A 817.25| 2020.0 D1 262.75 13 8 S 2372.75 27,29,31,33 3100 A 727.25| 2020.0 D1 352.75 14 VLBA | NYALES13S Chan Sky Tracks LO IF BBC | LO IF BBC BBC# 1 X 8365.75 2, 4, 6, 8 7600 B 765.75| 8080.0 A1 285.75 3 2 X 8445.75 10,12,14,16 7600 B 845.75| 8080.0 A1 365.75 4 3 X 8805.75 18,20,22,24 9600 D 794.25| 8080.0 B1 725.75 5 4 X 8925.75 26,28,30,32 9600 D 674.25| 8080.0 B1 845.75 6 5 S 2212.75 3, 5, 7, 9 3100 A 887.25| 1700.0 C1 512.75 9 6 S 2242.75 11,13,15,17 3100 A 857.25| 1700.0 C1 542.75 10 7 S 2282.75 19,21,23,25 3100 A 817.25| 1700.0 D1 582.75 13 8 S 2372.75 27,29,31,33 3100 A 727.25| 1700.0 D1 672.75 14 Special operations for non-VLBA stations: ========================================= All non-VLBA stations: Please note that due to the frequency sequence, phase-cal will not be visible with a 10 kHz viewing filter in the USB channels. If you have another means to verify phase-cal, please use it. If you have a Mark IV Decoder, please contact Ed.Himwich@nasa.gov if you would like advice on how to set it up to check phase-cal for this frequency sequence. Please check the procedures created by drudg. The discussion below represents our best understanding of the station configuration. If you find an error, please correct it and let us know so we can correct the catalog. HARTRAO: This station uses a DBBC rack. BBCs 3 & 4 are used at X-band with IF A, input 1. BBCs 5 & 6 are used at X-band with IF B, input 2. BBCs 9, 10, 13 & 14 are used for S-band with IF C, input 1. WETTZELL: This station uses a DBBC rack. BBCs 3 & 4 are used at X-band with IF A, input 1. BBCs 5 & 6 are used at X-band with IF B, input 1. BBCs 9 & 10 are used for S-band with IF C, input 1. BBCs 13 & 14 are used for S-band with IF D, input 1. ONSALA60: This station uses a DBBC rack. BBCs 3 & 4 are used at X-band with IF A, input 1. BBCs 5 & 6 are used at X-band with IF B, input 1. BBCs 9 & 10 are used for S-band with IF C, input 1. BBCs 13 & 14 are used at S-band with IF D, input 1. NYALES13: This station uses a DBBC rack. BBCs 3 & 4 are used at X-band with IF A, input 1. BBCs 5 & 6 are used at X-band with IF B, input 1. BBCs 9 & 10 are used for S-band with IF C, input 1. BBCs 13 & 14 are used at S-band with IF D, input 1. For Mark IV racks, the IF3 command in the procedure IFDSX assumes that VC3 and VC10 will be patched to High. Please verify that the switches for your IF3 module are wired this way, and if they are not please edit the IF3 command to change the switches. The standard wiring is described in "help=if3". If you have questions about the wiring, please contact Brian Corey at Haystack. If you wish to record back-up channels, please add appropriate instances of bbcxx=..., vcxx=..., valo=..., va=..., vblo=.., and/or vb=... commands to the BBC/VC setup procedure. CHECKLIST for non-VLBA stations =============================== Please follow the checklist below to ensure you have done all the necessary steps for this session: 1. Make .prc file with DRUDG and check them out, or use the procedures from the last RV session. Check out parity check procedures. 2. Make the .snp file with DRUDG. 3. Set up your system to monitor the clocks with the "gps-fmout" or "fmout-gps" commands. If you have questions about this, please contact Ed Himwich as soon as possible. 4. Send a "ready" message an hour or so before the session to the ivs-ops mail list (ivs-ops@lists.nasa.gov). Copy analysts@nrao.edu and vlbiobs@nrao.edu on your ready message. 5. Send a "start" message soon after you have started recording. Copy analysts@nrao.edu and vlbiobs@nrao.edu on the message. 6. At the end of the session, send a "finish" message summarizing how the session was conducted. Copy analysts@nrao.edu and vlbiobs@nrao.edu on your message. 7. Transfer your log file to your normal IVS data center. Correlation =========== This session will be correlated at the NRAO/VLBA on the VLBA DiFX software correlator. The VLBA correlator can now only read Mark6 modules. The non-VLBA stations will need to E-transfer their data to Haystack, where it will be copied onto a Mark6 module and shipped to the VLBA in Socorro, New Mexico. These stations will need to coordinate this with Haystack Observatory (contact: Jason SooHoo at jsoohoo@haystack.mit.edu). The VLBA needs to process this session as soon as possible because of limited media. So please try to set up the E-transfer as soon as possible after the session ends.