NOTES FOR: rd0210 Prepared by C. Thomas, NVI, Inc./GSFC =========================================================== Parameter values for experiment RD0210 Experiment description: R&D Scheduler: NASA Correlator: HAYSTACK Nominal start: 2002-338-18:00:00 Nominal end: 2002-339-18:00:00 Current yyyyddd: 2002338 (2002.93) ( 12613 MJD, WED. 4DEC.) Greenwich sidereal time: 22:53:30.74 (18: 0: 0 UT) Sun's RA and DEC: 16h 43.8m -22d 17.0 =========================================================== First observations Observation listing from file ./rd0210.skd for experiment RD0210 Source Start DURATIONS name yyddd-hhmmss Ap Gc Kk Ma Ny Wf Wz 1357+769 02338-180000| 68 244 448 478 334 478 335| =========================================================== Last observations Source Start DURATIONS name yyddd-hhmmss Ap Gc Kk Ma Ny Wf Wz 2234+282 02339-172637| 38 336 376 376 170| NRAO512 02339-173403| 102 242 242 | CTA26 02339-173436| 71 71| 1958-179 02339-174420| 170 170| =========================================================== Notes by Dan MacMillan, Feb 27, 2002 Purpose of Experiment The goal of this experiment is to investigate instrumental errors by scheduling observations with very high SNR. The high SNR is necessary in order to allow phase delay ambiguities to be resolved. With the much more precise phase delay observables one can then investigate possible systematic variations. For instance, we have seen subdaily cycles in the time variation of solution residuals. If these systematic variations can be identified, it may be possible to introduce corrections for them. Additionally, we will investigate intra-scan variations of residual fringe phase. Usually VLBI experiments are scheduled with target minimum SNRs of 20 at X-band and 15 at S-band. To resolve phase delays, we chose a much higher minimum of 80 at X-band and 60 at S-band. Once this experiment is analyzed, we will assess whether such high limits are necessary since this significantly reduces the number of observations/hour that can be observed at each site. Type of Experiment This experiment uses a 7-station northern hemisphere geodetic network. We had to compromise between the parameters of a standard geodetic schedule made with smooth sky coverage and the high SNR requirement that significantly reduces the possible number of station observations/hour. The antenna at Harteboestoek was available, but we decided not to include it because schedule simulations showed that HartRAO was not connected well enough to observe more than 2-3 observations/hour. Simulations showed that EOP formal uncertainties were not significantly improved by including HartRAO at this level. The high SNR requirement reduced the number of observations for this network significantly from an average of about 12-15 observations/hour for other routine schedules to 7-8 observations/hour (for non-HartRAO sites). Another consideration in making the schedule was that we decided to reduce the possible number of sources observed to increase the average number of observations made on each source. The standard list of 70 sources was reduced to 36 sources by taking out infrequently observed sources or sources that were redundant in the sense of being close to other more frequently observed sources. We tried to maintain good low elevation coverage for atmosphere parameter estimation. =========================================================== SKED Summary from file ./rd0210.skd for experiment RD0210 (all scans with at least one subnet station) Average number of obs. per baseline per source (normalized by up-time) = 5.4 Min = .0 Max = 38.9 (Baseline Gc-Kk on 1334-127) RMS = 7.1 Total time: 1427 minutes ( 23.8 hours). Key: Ap=ALGOPARK Gc=GILCREEK Kk=KOKEE Ma=MATERA Ny=NYALES20 Wf=WESTFORD Wz=WETTZELL Ap Gc Kk Ma Ny Wf Wz Avg % obs. time: 16 27 33 34 32 33 36 30 % cal. time: 2 2 1 2 2 2 2 2 % slew time: 57 17 11 16 12 9 8 19 % idle time: 23 53 52 46 52 54 53 48 # of tapes : .9 1.5 1.9 2.0 2.1 2.0 2.1 total # scans: 212 208 171 179 184 174 209 191 # scans/hour : 8 8 7 7 7 7 8 8.0 Avg scan (sec): 65 111 167 166 153 165 148 139 tape change times (hhmm): 0000 0942 0814 0440 0330 0529 0544 0000 0000 0000 0000 1646 0000 1744 # OF OBSERVATIONS BY BASELINE | Ap Gc Kk Ma Ny Wf Wz StnTotal ------------------------------------------ Ap|212 128 103 74 98 162 95 660 Gc| 208 155 48 112 89 68 600 Kk| 171 18 75 75 31 457 Ma| 179 115 85 178 518 Ny| 184 101 139 640 Wf| 174 100 612 Wz| 209 611 Number of 2-station scans: 147 Number of 3-station scans: 98 Number of 4-station scans: 52 Number of 5-station scans: 45 Number of 6-station scans: 34 Number of 7-station scans: 16 Total # of scans, observations: 392 2049 =========================================================== Recording mode Name Code GEOSX4F 4F Recording mode setup for: ALGOPARK Mode Tot.Rate Tot.BandW #chan #bits Barrel Mk341:2 256.000 Mbits 128.000 MHz 14 1 NONE Chan.BW #Subpasses Tracks(*fan) Tot.tracks Speed 8.00 MHz 1 16(*2) 32 160.00 X-band spanned bw= 720.0 MHz rms spanned bw= 280.4 MHz S-band spanned bw= 120.0 MHz rms spanned bw= 48.8 MHz Effective number of channels recorded per sub-pass X S Total 10.000 6.000 16.000 Recording mode setup for: GILCREEK Mode Tot.Rate Tot.BandW #chan #bits Barrel VLBA1:2 256.000 Mbits 128.000 MHz 14 1 8:1 Chan.BW #Subpasses Tracks(*fan) Tot.tracks Speed 8.00 MHz 1 16(*2) 32 160.00 X-band spanned bw= 720.0 MHz rms spanned bw= 280.4 MHz S-band spanned bw= 120.0 MHz rms spanned bw= 48.8 MHz Effective number of channels recorded per sub-pass X S Total 10.000 6.000 16.000 Recording mode setup for: KOKEE Mode Tot.Rate Tot.BandW #chan #bits Barrel VLBA1:2 256.000 Mbits 128.000 MHz 14 1 16:1 Chan.BW #Subpasses Tracks(*fan) Tot.tracks Speed 8.00 MHz 1 16(*2) 32 160.00 X-band spanned bw= 720.0 MHz rms spanned bw= 280.4 MHz S-band spanned bw= 120.0 MHz rms spanned bw= 48.8 MHz Effective number of channels recorded per sub-pass X S Total 10.000 6.000 16.000 Recording mode setup for: MATERA NYALES20 WESTFORD WETTZELL Mode Tot.Rate Tot.BandW #chan #bits Barrel Mk341:2 256.000 Mbits 128.000 MHz 14 1 16 Chan.BW #Subpasses Tracks(*fan) Tot.tracks Speed 8.00 MHz 1 16(*2) 32 160.00 X-band spanned bw= 720.0 MHz rms spanned bw= 280.4 MHz S-band spanned bw= 120.0 MHz rms spanned bw= 48.8 MHz Effective number of channels recorded per sub-pass X S Total 10.000 6.000 16.000 =========================================================== Tape types ID Station Tape length Density Ap ALGOPARK 17400feet (Thin ) 56250. (High) Gc GILCREEK 17400feet (Thin ) 56700. (High) Kk KOKEE 17400feet (Thin ) 56700. (High) Ma MATERA 17400feet (Thin ) 56250. (High) Ny NYALES20 17400feet (Thin ) 56250. (High) Wf WESTFORD 17400feet (Thin ) 56250. (High) Wz WETTZELL 17400feet (Thin ) 56250. (High) =========================================================== SNR Targets Minimum SNR by baseline for multi-baseline scans X-band (margin 5) S-band (margin 5) Ap Gc Kk Ma Ny Wf Ap Gc Kk Ma Ny Wf Gc 80 Gc 60 Kk 80 80 Kk 60 60 Ma 80 80 80 Ma 60 60 60 Ny 80 80 80 80 Ny 60 60 60 60 Wf 80 80 80 80 80 Wf 60 60 60 60 60 Wz 80 80 80 80 80 80 Wz 60 60 60 60 60 60