Session Notes for rd1709 Prepared by K. Le Bail, NVI, Inc./GSFC =========================================================== PURPOSE AND GENERAL NOTES =========================================================== GAIA proposal The Laboratory d'Astrophysique de Bordeaux (LAB) subnmitted in 2012 a proposal to observe 195 ICRF2 transfer sources in the context of the GAIA mission. These sources were added to the GSFC monitoring program and 37 sources were scheduled in Gaia-dedicated R&D sessions. In February 2017, we studied the position uncertainties and the observation frequency of the 195 sources of the LAB proposal. Twenty-seven of these sources have a bad observation frequency: they were observed successfully in less than five sessions a year while the LAB requirement was twelve sessions a year. Most of these sources have bad uncertainties compared to the other sources of the set (larger than 50 microas). Three additional sources have good position uncertainties and an observation frequency of five to eleven successful sessions a year. However they are sources that were observed in previous Gaia-dedicated R&D sessions and the concern is that if they are not scheduled in coming dedicated R&D sessions, their observation frequency may drop. The sources scheduled in the Gaia-dedicated R&D sessions scheduled to observe after March 1st, 2017 are these thirty sources. When compared to the previous categories determined by the LAB, one source was in category 1, five sources were in category 2, five sources were in category 3 and nineteen sources were in category 4. In RD1709, we could schedule all thirty sources in the astro mode of sked. We used a maxscan value of 480 seconds. Forty of the good geodetic sources are used as base of a stable source set and uniform sky coverage. We use the sked flux catalog for all sources. Wettzell will observe INT I17269 during the time from 1815 UT to 1945 UT. The command FILL was used on all stations and on the entire period with a fill_off (buffer offset) of 5 seconds. ----- Parameter listing -------------------------------------- Experiment: RD1709 Description R&D-09/2017 Scheduler: NASA Correlator: SHAO Start: 2017-269-17:30:00 End: 2017-270-17:30:00 Current yyyyddd: 2017269 (2017.74) ( 18023 MJD, TUES 26SEP.) Greenwich sidereal time: 17:52:50 (17:30:00 UT) Sun's RA and DEC: 12h 14.0m -1d 31.0 =========================================================== First observations Observation listing from file ./rd1709.skd for experiment RD1709 Source Start DURATIONS name yyddd-hhmmss Hh Ho Ny T6 Wz 2318+049 17269-173000| 66 123 480 112 480| 0131-522 17269-173447| 177 177 135 | 0657+172 17269-174047| 62 73 73 | 0804+499 17269-174339| 204 104 204| 2314-409 17269-174503| 377 377 | End of listing. =========================================================== Observation listing from file ./rd1709.skd for experiment RD1709 Source Start DURATIONS name yyddd-hhmmss Hh Ho Ny T6 Wz 2329-415 17270-171820| 176 176 176 | 0316-444 17270-172306| 164 164 | 2141+175 17270-172457| 40 40 40| 2000+472 17270-172617| 108 108| 0528-250 17270-172731| 144 144 | 1732+389 17270-172916| 39 39 39| End of listing. =========================================================== SKED Summary from file ./rd1709.skd for experiment RD1709 (all scans with at least one subnet station) Average number of obs. per baseline per source(normalized by up-time) = 5.4 Min = 0.0 Max = 38.9 (Baseline Hh-T6 on 0131-522) RMS = 7.5 Total time: 1440 minutes ( 24.0 hours). Key: Hh=HARTRAO Ho=HOBART26 Ny=NYALES20 T6=TIANMA65 Wz=WETTZELL Hh Ho Ny T6 Wz Avg % obs. time: 44 48 67 45 57 52 % cal. time: 2 2 2 3 2 2 % slew time: 30 22 11 43 7 23 % idle time: 23 27 18 8 33 22 total # scans: 146 162 200 240 196 188 # scans/hour : 6 7 8 10 8 8 Avg scan (sec): 261 255 290 161 251 243 # data tracks: 32 32 32 32 32 # Mk5 tracks: 32 32 32 32 32 Total TB(M5): 2.4 2.6 3.7 2.5 3.1 2.9 # OF OBSERVATIONS BY BASELINE | Hh Ho Ny T6 Wz Total ----------------------------------- Hh| 64 56 67 68 255 Ho| 26 135 7 232 Ny| 103 158 343 T6| 80 385 Wz| 313 Number of 2-station scans: 221 Number of 3-station scans: 145 Number of 4-station scans: 13 Number of 5-station scans: 3 Total number of scans: 382 Total number of obs: 764 Total integrated obs-time: 172457 Average obs-time: 225.7 Histogram of observation durations Dur: 25 50 75 100 125 150 175 200 225 250 275 300 325 350 375 400 425 450 475 500 #Obs: | 87| 74| 56| 54| 53| 44| 54| 34| 26| 21| 19| 19| 11| 26| 34| 10| 3| 12| 127| Average X-band SNRs by baseline | Hh Ho Ny T6 Wz AVG ---------------------------------- Hh| 29 34 81 43 47 Ho| 24 79 33 58 Ny| 101 73 71 T6| 149 100 Wz| 85 Average S-band SNRs by baseline | Hh Ho Ny T6 Wz AVG ---------------------------------- Hh| 29 19 52 26 32 Ho| 17 57 30 44 Ny| 43 30 31 T6| 59 53 Wz| 37 =========================================================== Recording mode Name Code GEOSX8N 8F Recording mode for: HARTRAO HOBART26 NYALES20 TIANMA65 WETTZELL Mode Tot.Rate Tot.BandW #BBC #bits Barrel Mk341:1 512 Mbits 128 MHz 14 2 NONE Chan.BW #Subpasses Tracks(*fan) Tot.tracks 8.00 MHz 1 32(*1) 32 X-band spanned bw= 720.0 MHz rms spanned bw= 280.4 MHz S-band spanned bw= 140.0 MHz rms spanned bw= 50.9 MHz Effective number of 1-bit channels recorded per sub-pass X S Total 19.13 11.48 30.61 =========================================================== Tape types ID Station Tape length Density Passes Hh HARTRAO Mark5B Ho HOBART26 Mark5A Ny NYALES20 Mark5B T6 TIANMA65 Mark5B Wz WETTZELL Mark5B =========================================================== SNR targets Minimum SNR by baseline for multi-baseline scans X-band (margin 0) S-band (margin 0) X-band (ast_margin 0) S-band (ast_margin 0) Hh Ho Ny T6 Hh Ho Ny T6 Ho 20 Ho 15 Ny 20 20 Ny 15 15 T6 20 20 20 T6 15 15 15 Wz 20 20 20 20 Wz 15 15 15 15 ===========================================================