RV158 (Astrometric/Geodetic VLBA-158) 2023 APR 25 17:30 UTC DOY 115 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. RV158 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 8 non-VLBA stations scheduled - HARTRAO, HOBART26, NYALE13S, NYALES20, ONSALA60, SESHAN25, WETTZELL and YARRA12M. These non-VLBA stations should see the "Special operations notes for non-VLBA stations" section below for special instructions. To facilitate fringe-finding, there are some long scans on fairly strong sources with many antennas near the beginning and end of 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 Ny Ns On Ov Pt Sc Sh Wz Yg 3C418 23115-173000| 300 352 329 354 300 334 338 343 351 480 354 300 332 304 480 | 1751+288 23115-173632| 303 440 300 348 432 440 300 300 440| 0403-132 23115-173808| 319 331 331 322 327 328 300 | 1803+784 23116-164911| 300 300 316 304 300 300 305 308 319 425 301 300 313 425 413 | 1751+288 23116-165511| 323 300 480 323 334 480 322 334| 0403-132 23116-165700| 387 300 373 388 383 388 372 387 | 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 47% to 61%, the average idle time decreases from 25% to 11% and the average scan time increases from 103 seconds to 129 seconds. The observing time increases most at the faster antennas and least at the slower antennas. Purpose ======= This is the second 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: rv158.skd. At the IVS Data Center (https://cddis.nasa.gov/archive/vlbi/ivsdata/aux/2023/rv158/ Sked file: rv158.skd Text file: rv158.txt At the VLBA/NRAO: Sked file: rv158.skd Vex file: rv158.vex Text file: rv158.txt Summary file: rv158.sksum This session uses the VLBA stations and 8 IVS stations. The IVS stations are: HARTRAO, HOBART26, NYALES20, NYALE13S, ONSALA60, SESHAN25, WETTZELL and YARRA12M. 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 Ny=NYALES20 Ns=NYALE13S On=ONSALA60 Ov=OV-VLBA Pt=PIETOWN Sc=SC-VLBA Sh=SESHAN25 Wz=WETTZELL Yg=YARRA12M Br Fd Hh Hn Ho Kp La Mk Nl Ny Ns On Ov Pt Sc Sh Wz Yg Avg % obs. time: 62 62 50 62 58 62 62 58 61 69 67 67 62 62 59 51 64 70 61 % cal. time: 5 5 3 5 3 5 5 4 5 4 3 4 5 5 5 3 4 3 4 % slew time: 25 26 41 25 32 26 26 23 26 17 2 18 26 27 25 29 9 9 23 % idle time: 7 5 5 7 6 6 5 14 7 9 27 10 6 5 11 16 22 16 11 total # scans: 424 459 239 415 271 460 460 375 441 341 270 324 451 465 407 285 340 277 372 # scans/hour : 18 19 10 17 11 19 19 16 18 14 11 14 19 19 17 12 14 12 16 Avg scan (sec): 127 116 181 129 186 116 117 133 120 174 214 178 118 114 124 154 163 220 148 # data tracks: 16 16 16 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 16 16 16 Total TB(M5): 3.45 3.42 2.76 3.44 3.22 3.41 3.43 3.19 0.00 3.79 3.70 3.68 0.00 3.41 3.24 2.81 3.54 3.89 3.02 # OF OBSERVATIONS BY BASELINE | Br Fd Hh Hn Ho Kp La Mk Nl Ny Ns On Ov Pt Sc Sh Wz Yg Total ---------------------------------------------------------------------------------------------------- Br| 330 2 261 20 342 347 264 306 133 108 77 372 342 219 62 78 15 3278 Fd| 16 289 8 426 438 255 371 104 86 69 382 443 298 44 77 6 3642 Hh| 32 152 8 11 0 21 21 12 69 4 11 35 82 84 163 723 Hn| 1 270 285 161 342 160 124 128 248 283 339 37 142 0 3102 Ho| 13 9 69 1 20 12 13 16 9 1 166 19 258 787 Kp| 425 276 347 103 82 65 405 437 276 48 70 9 3602 La| 258 373 109 90 73 389 452 290 45 80 7 3681 Mk| 204 86 70 41 291 263 153 86 39 63 2579 Nl| 130 105 93 323 371 332 36 107 0 3462 Ny| 227 206 108 108 124 93 209 26 1967 Ns| 186 89 88 96 68 156 17 1616 On| 62 72 124 74 270 27 1649 Ov| 393 235 62 62 12 3453 Pt| 292 46 78 7 3695 Sc| 23 139 0 2976 Sh| 83 166 1221 Wz| 32 1725 Yg| 808 Number of 2-station scans: 0 Number of 3-station scans: 324 Number of 4-station scans: 217 Number of 5-station scans: 95 Number of 6-station scans: 63 Number of 7-station scans: 90 Number of 8-station scans: 70 Number of 9-station scans: 63 Number of 10-station scans: 109 Number of 11-station scans: 30 Number of 12-station scans: 22 Number of 13-station scans: 14 Number of 14-station scans: 17 Number of 15-station scans: 10 Number of 16-station scans: 0 Number of 17-station scans: 0 Number of 18-station scans: 0 Total number of scans: 1124 Total number of obs: 21983 INTENSIVE BREAKS ================ WETTZELL will drop out from ~18:15-19:45 on DOY 115 to observe the one-hour UT1 Intensive session. And there may also be a USNO/VLBA Intensive at about the same time, in which case HN-VLBA and MK-VLBA and maybe more VLBA stations will drop out for ~1.5 hours. SOURCE SELECTION ================ There are a total of 84 sources in this session: 63 are from the geodetic source list; 13 are weak sources being re-observed or observed for the first time i an IVS session; and 8 are far south sources with few observations being observed to reduce their position uncertainties. 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 | YARRA12M Chan Sky Tracks LO IF BBC | LO IF BBC BBC# 1 X 8365.75 2, 4, 6, 8 7600 B 765.75| 7600.0 A1 765.75 3 2 X 8445.75 10,12,14,16 7600 B 845.75| 7600.0 A1 845.75 4 3 X 8805.75 18,20,22,24 9600 D 794.25| 7600.0 B4 1205.75 5 4 X 8925.75 26,28,30,32 9600 D 674.25| 7600.0 B4 1325.75 6 5 S 2212.75 3, 5, 7, 9 3100 A 887.25| 1900.0 C2 312.75 9 6 S 2242.75 11,13,15,17 3100 A 857.25| 1900.0 C2 342.75 10 7 S 2282.75 19,21,23,25 3100 A 817.25| 1900.0 D2 382.75 13 8 S 2372.75 27,29,31,33 3100 A 727.25| 1900.0 D2 472.75 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 | NYALES20 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 C1 262.75 13 8 S 2372.75 27,29,31,33 3100 A 727.25| 2020.0 C1 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 VLBA | SESHAN25 Chan Sky Tracks LO IF BBC | LO IF BBC BBC# 1 X 8365.75 2, 4, 6, 8 7600 B 765.75| 8100.0 A 265.75 3 2 X 8445.75 10,12,14,16 7600 B 845.75| 8100.0 A 345.75 4 3 X 8805.75 18,20,22,24 9600 D 794.25| 8100.0 B 705.75 5 4 X 8925.75 26,28,30,32 9600 D 674.25| 8100.0 B 825.75 6 5 S 2212.75 3, 5, 7, 9 3100 A 887.25| 2000.0 C 212.75 9 6 S 2242.75 11,13,15,17 3100 A 857.25| 2000.0 C 242.75 10 7 S 2282.75 19,21,23,25 3100 A 817.25| 2000.0 D 282.75 13 8 S 2372.75 27,29,31,33 3100 A 727.25| 2000.0 D 372.75 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. SESHAN25 The logs from SESHAN25 indicate that the station uses a VLBA5 rack, but we are not sure that is correct, please let us know. BBCs 3 & 4 are used at X-band with IF A, input NOR. BBCs 5 & 6 are used at X-band with IF B, input NOR. BBCs 9 & 10 are used for S-band with IF C, input NOR. BBCs 13 & 14 are used at S-band with IF D, input NOR. 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.