RV159 (Astrometric/Geodetic VLBA-159) 2023 MAY 23 17:30 UTC DOY 143 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. RV159 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 7 non-VLBA stations scheduled - HARTRAO, HOBART26, NYALE13S, NYALES20, ONSALA60, SESHAN25 and WETTZELL. 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 Observation listing from file ./rv159.skd for experiment RV159 Source Start DURATIONS name yyddd-hhmmss Br Fd Hh Hn Ho Kp La Mk Nl Ny Ns On Ov Pt Sc Sh Wz 1803+784 23143-173000| 321 309 300 363 309 303 303 376 376 300 328 362 300 319 340| 0700-197 23143-173657| 300 331 310 303 307 302 331| 2214+241 23143-173712| 480 480 300 443 480 375 | 0016+731 23144-163800| 320 300 326 348 300 300 311 300 375 345 343 300 326 310 375| 2126-158 23144-164526| 321 321 300 304 300 300 | 0454-234 23144-164542| 318 300 300 318 312 318 300 | 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 46% to 57%, the average idle time decreases from 23% to 12% and the average scan time increases from 98 seconds to 117 seconds. The observing time increases most at the faster antennas and least at the slower antennas. Purpose ======= This is the third 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: rv159.skd. At the IVS Data Center (https://cddis.nasa.gov/archive/vlbi/ivsdata/aux/2023/rv159/ Sked file: rv159.skd Text file: rv159.txt At the VLBA/NRAO: Sked file: rv159.skd Vex file: rv159.vex Text file: rv159.txt Summary file: rv159.sksum This session uses the VLBA stations and 7 IVS stations. The IVS stations are: HARTRAO, HOBART26, NYALES20, NYALE13S, ONSALA60, SESHAN25 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 Ny=NYALES20 Ns=NYALE13S On=ONSALA60 Ov=OV-VLBA Pt=PIETOWN Sc=SC-VLBA Sh=SESHAN25 Wz=WETTZELL Br Fd Hh Hn Ho Kp La Mk Nl Ny Ns On Ov Pt Sc Sh Wz Avg % obs. time: 59 59 41 58 45 59 59 54 60 62 52 67 59 59 55 50 62 57 % cal. time: 5 5 3 5 4 5 5 5 5 3 3 4 5 5 5 4 4 5 % slew time: 29 29 48 28 41 29 28 28 28 15 2 22 28 28 28 33 10 27 % idle time: 7 6 6 8 9 6 6 13 6 18 42 6 6 6 11 12 22 12 total # scans: 450 466 273 434 324 465 469 416 449 301 238 384 452 469 422 348 371 395 # scans/hour : 19 19 11 18 14 19 20 17 19 13 10 16 19 20 18 15 15 16 Avg scan (sec): 113 109 131 115 120 110 109 112 115 179 190 150 113 110 112 125 145 126 # 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): 3.24 3.26 2.29 3.20 2.49 3.27 3.28 2.98 0.00 3.45 2.90 3.69 3.27 3.29 3.02 2.77 3.44 2.93 # OF OBSERVATIONS BY BASELINE | Br Fd Hh Hn Ho Kp La Mk Nl Ny Ns On Ov Pt Sc Sh Wz Total ----------------------------------------------------------------------------------------------- Br| 321 1 271 21 337 344 253 326 90 80 48 357 342 221 52 43 3107 Fd| 5 298 28 424 429 232 363 69 60 43 370 428 288 28 44 3430 Hh| 17 192 1 5 0 8 19 12 55 0 3 39 100 74 531 Hn| 2 285 313 162 348 77 90 80 257 297 318 25 84 2924 Ho| 38 27 84 10 27 2 15 38 34 8 174 26 726 Kp| 419 256 347 69 60 41 395 441 265 34 40 3452 La| 234 380 73 66 45 375 445 282 30 47 3514 Mk| 194 74 43 25 279 245 148 95 17 2341 Nl| 79 76 51 320 362 299 30 57 3250 Ny| 63 132 77 76 54 99 106 1184 Ns| 107 54 63 68 43 88 975 On| 41 41 75 59 292 1150 Ov| 391 237 39 35 3265 Pt| 274 33 42 3517 Sc| 13 90 2679 Sh| 60 914 Wz| 1145 Number of 2-station scans: 568 Number of 3-station scans: 304 Number of 4-station scans: 90 Number of 5-station scans: 63 Number of 6-station scans: 54 Number of 7-station scans: 74 Number of 8-station scans: 75 Number of 9-station scans: 66 Number of 10-station scans: 117 Number of 11-station scans: 45 Number of 12-station scans: 12 Number of 13-station scans: 8 Number of 14-station scans: 1 Number of 15-station scans: 3 Number of 16-station scans: 0 Number of 17-station scans: 0 Total number of scans: 1480 Total number of obs: 19052 INTENSIVE BREAKS ================ WETTZELL will drop out from ~18:15-19:45 on DOY 143 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 74 sources in this session: 60 are from the geodetic source list and 14 are weak sources being re-observed on the VLBA baselines to improve their positions. 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 | 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.