RV149 (Astrometric/Geodetic VLBA-149) 2021 SEP 08 18:00 UTC DOY 251 Notes prepared by David Gordon (GMU/USNO) and Ed Himwich (NVI/GSFC) 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 have been changed from the last few RV's to accommodate HOBART26. They are: 2212.75, 2242.75, 2282.75 and 2372.75 MHz. However HOBART26 will not be particpating this time and is being replaced by YARRA12M. 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. RV149 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 6 non-VLBA stations scheduled - HARTRAO, NYALE13S, ONSALA60, SESHAN25, WETTZELL and YARRA12M. The 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 Kp La Mk Nl Ns On Ov Pt Sc Sh Wz Yg Ny 1803+784 21251-180000| 304 300 404 300 300 317 412 434 364 302 300 412 434 396 420| 0606-223 21251-180747| 300 300 300 300 300 300 300 300 | 1334-127 21251-181418| 336 327 300 336 329 330 332 333 330 300 | 0458-020 21252-172208| 309 302 302 304 304 303 300 309 | 1334-127 21252-172904| 326 300 300 325 319 307 318 321 301 326 | 1053+704 21252-174549| 300 300 309 300 300 308 300 326 307 300 300 315 311 326 258| 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 62%, and the average idle time decreases from 22% to 12%. The observing time increases most at the faster antennas and least at the slower antennas. Purpose ======= This is the fifth of six coordinated astrometric/geodetic sessions in 2021 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. These sessions are being coordinated by the geodetic/astrometric VLBI programs of USNO, NASA and NRAO. They have been designed so that the same data set may be used by each agency for its particular goals. Schedule information ==================== This is a new schedule generated by David Gordon at USNO using sked. Schedule file name: rv149.skd At the IVS Data Center (ftp://cddisa.gsfc.nasa.gov/vlbi/ivsdata/aux/2021/rv149): Sked file: rv149.skd Text file: rv149.txt At the VLBA/NRAO: Sked file: rv149.skd Vex file: rv149.vex Text file: rv149.txt Summary file: rv149.sksum This session uses the VLBA stations and 6 IVS stations. The IVS stations are: HARTRAO, NYALE13S, ONSALA60, SESHAN25, WETTZELL and YARRA12M. (NYALES20 was tagged along but is not expected to participate.) Below is the sked summary. Key: Br=BR-VLBA Fd=FD-VLBA Hh=HARTRAO Hn=HN-VLBA 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 Kp La Mk Nl Ny Ns On Ov Pt Sc Sh Wz Yg Avg % obs. time: 52 54 44 48 55 53 47 51 33 52 54 52 54 48 43 45 42 49 % cal. time: 5 5 3 5 5 5 5 5 4 4 4 5 5 5 4 4 4 4 % slew time: 22 22 46 23 22 22 26 23 16 2 19 23 22 23 35 9 13 22 % idle time: 19 18 6 23 17 19 21 20 46 41 23 19 18 23 17 40 41 25 total # scans: 418 417 284 416 413 421 422 419 309 313 332 429 417 399 386 351 340 381 # scans/hour : 17 17 12 17 17 18 18 17 13 13 14 18 17 17 16 15 14 16 Avg scan (sec): 108 111 132 99 115 110 96 106 94 143 140 104 112 105 96 112 106 110 # data tracks: 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 Total TB(M5): 2.89 2.98 2.41 2.64 3.05 2.96 2.59 2.83 1.85 2.87 2.97 2.85 3.00 2.67 2.37 2.51 2.30 2.69 # OF OBSERVATIONS BY BASELINE | Br Fd Hh Hn Kp La Mk Nl Ny Ns On Ov Pt Sc Sh Wz Yg Total ----------------------------------------------------------------------------------------------- Br| 331 31 304 332 341 232 329 144 141 120 328 337 268 77 137 16 3468 Fd| 45 316 392 401 224 369 121 117 118 334 406 301 71 136 11 3693 Hh| 67 43 46 0 52 53 63 113 13 44 84 62 137 110 963 Hn| 305 325 166 348 144 146 155 265 317 340 60 176 1 3435 Kp| 389 235 354 121 116 119 346 398 293 73 137 12 3665 La| 221 375 125 121 121 333 408 307 69 140 7 3729 Mk| 209 100 77 51 293 228 155 120 43 80 2434 Nl| 130 129 130 311 369 316 71 152 4 3648 Ny| 205 188 116 123 116 84 148 18 1936 Ns| 210 99 119 114 90 170 10 1927 On| 93 120 134 60 236 24 1992 Ov| 340 249 81 108 20 3329 Pt| 303 72 137 11 3732 Sc| 31 160 0 3171 Sh| 72 209 1302 Wz| 25 2114 Yg| 558 Number of 2-station scans: 431 Number of 3-station scans: 235 Number of 4-station scans: 92 Number of 5-station scans: 51 Number of 6-station scans: 49 Number of 7-station scans: 31 Number of 8-station scans: 47 Number of 9-station scans: 45 Number of 10-station scans: 109 Number of 11-station scans: 39 Number of 12-station scans: 39 Number of 13-station scans: 41 Number of 14-station scans: 26 Number of 15-station scans: 8 Number of 16-station scans: 0 Number of 17-station scans: 0 Total number of scans: 1243 Total number of obs: 22548 INTENSIVE BREAKS ================ WETTZELL will drop out from ~18:15-19:45 on DOY 251 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 will drop out for ~2 hours. SOURCE SELECTION ================ There are a total of 73 sources in this session: 60 are from the geodetic source list and 13 are weak sources being re-observed or observed for the first time at S/X bands. 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 at HOBART26. 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| 7600.1 A 765.65 3 2 X 8445.75 10,12,14,16 7600 B 845.75| 7600.1 A 845.65 4 3 X 8805.75 18,20,22,24 9600 D 794.25| 8080.0 C 725.75 5 4 X 8925.75 26,28,30,32 9600 D 674.25| 8080.0 C 845.75 6 5 S 2212.75 3, 5, 7, 9 3100 A 887.25| 1540.1 B 672.65 9 6 S 2242.75 11,13,15,17 3100 A 857.25| 1540.1 B 702.65 10 7 S 2282.75 19,21,23,25 3100 A 817.25| 1540.1 B 742.65 13 8 S 2372.75 27,29,31,33 3100 A 727.25| 1540.1 B 832.65 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@aoc.nrao.edu on your ready message. 5. Send a "start" message soon after you have started recording. Copy analysts@nrao.edu and vlbiobs@aoc.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@aoc.nrao.edu on your message. 7. Transfer your log file to your normal IVS data center. The directories for the IVS servers are listed below: ftp ivsopar.obspm.fr/ivsincoming ftp ivs.bkg.bund.de/ivsincoming 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.