BRD01 (Bonn Research and Development 01) 1999 July 01 Notes prepared by Leonid Petrov, Bonn VLBI group Schedule name: brd01.skd on CDDISA [jul99] Nominal Start: 10:00 U.T. on July 01 (day 182) Source Start DURATIONS name yyddd-hhmmss Ma Mc Tg Wz 0316+413 99182-100000| 90 90 90 90| Nominal Stop : 10:00 U.T. on July 01 (day 183) Source Start DURATIONS name yyddd-hhmmss Ma Mc Tg Wz 0316+413 99183-095800| 90 90 90 90| Duration: 24 hours Correlator: BONN Special notes ============= THIS IS ABNORMAL EXPERIMENT!! 1) The frequency setup will be changed 14 times during the experiment within [-21,+8] MHz with respect to a SX frequency setup. 2) Station MEDICINA will be swapping polarization LCP <---> RCP 96 times during the experiment. The schedule of polarization changes is attached in Appendix A. 3) Procedure files should be generated by DRUDGE since non-standard frequency setups are used. Purpose ======= The primary purpose of the experiment BRD01 is to investigate differences in group delay, phase delay, amplitude and phase for each channel, residual phases for RR scans and for cross-polarized RL scans. Stations MATERA, WETTZELL, TIGOWTZL will record right circular polarization (RCP) during entire experiment while MEDICINA will swap RCP (right circular polarization) to LCP (left circular polarization) 96 times. 145 out of 273 scans are scheduled as RR and 128 scans are scheduled as RL. Channel frequencies will be changed during the experiments 14 times in order to scan the band. The secondary purposes: a) to investigate how phase calibration phase and amplitude, difference group minus phase delay vary with change of frequencies of individual videoconverters within [-21,+8] MHz b) to get a series of group and phase delays with very high SNR (higher than 200) at 59 meters baseline TIGOWTZL/WETTZELL and to investigate differences group minus phase delay for such measurements. Polarization test conducted on 14-DEC-98 showed that European geodetic VLBI stations have considerable polarization impurity. It was found that * RL fringes were found at all baselines, and the fringe amplitude for RL scans was at the level 0.08-0.20 of the fringe amplitude for RR scans. It means that the effect of polarization impurity in normal RR scans is at the level 0.01-0.04, roughly 10 times smaller than in RL scans. * Individual fringe amplitudes vary up to 3 times within the band of registration (360MHz at X-band and 80MHz at S-band) * Bandwidth synthesis for RL scans at X-band failed: residual phases scattered up to 2 radians. Bandwidth synthesis for RL scans at S-band was poor: residual phases scattered up to 0.5 radians. The ratio of residual phase scattering at X-band and S-band is 4. This ratio is about the ratio of frequencies - 8.2/2.2 . It is an indication that the effect which caused phase scattering is a path-like but not phase-like. We expect that * Almost all stations have instrumental polarization exceeding 1% and some stations have instrumental polarization exceeding 10%. * Instrumental polarization depends on time relatively weakly, but may change after any manipulation with appliances. * Instrumental polarization shows strong frequency dependence at many stations. Dependence of instrumental polarization on frequency has quasi-sinusoidal modulation with periods of about the physical scales of the antenna: tens of MHz. Objectives ========== * To measure polarization impurity on stations participating in the experiment. * To investigate dependence of instrumental polarization on o time o frequency o parallactic angle * To investigate how residual phases depend on o time o frequency o parallactic angle * To determine relative jumps in group and phase delays for RR and RL scans. * To make phase connection of RR and RL scans. * To investigate misclosure for RR and RL scans for o group delays o multiband fringe phases o individual phases Network ======= Station MEDICINA is able to swap RCP and LCP automatically and therefore was chosen as a key station. Two other stations for cross-polarization scans are MATERA and WETTZELL. Triangle: MATERA MEDICINA WETTZELL has baselines 522, 597 and 990 kilometers. Station TIGOWTZL is added to all scans. SNR for cross-polarized scans at the baseline TIGOWTZL/MEDICINA is allowed to be below a detection limit and fringes for 75% of such scans will not be detected. Purpose of station TIGOWTZL participation is to investigate the differences group delay minus phase delay at the 59 meter long baseline WETTZELL/TIGOWTZL. Sources ======= Expected fringe amplitudes in RL scans are only 10% of the amplitudes in RR scans. Therefore only the strongest sources can be scheduled. The information about fluxes of the strongest sources is taken from the table "Physical characteristics ICRF" ( http://maia.usno.navy.mil/icrf/icrf.car ) and from the UMRAO database (http://www.astro.lsa.umich.edu/obs/radiotel/umrao.html). |--------------------|----------------|--------------|--------------| | IAU name name | 8.0GHz 4.8GHz | 6cm 15cm | P-8.0 P-4.8 | | (1) (2) | (3) (4) | (5) (6) | (7) (8) | |--------------------|----------------|--------------|--------------| | 0316+413 3C84 | 21.15 21.35 | 18.72 24.80 | 0.14 0.25 | | 0538+508 3C147 | 4.64 7.92 | 8.18 12.98 | 0.10 0.21 | | 0552+398 DA193 | 5.77 5.74 | 5.43 3.40 | 2.22 0.87 | | 0923+392 4C39.25 | 10.64 12.53 | 7.57 4.20 | 1.09 1.08 | | 1226+023 3C273B | 38.84 43.27 | 43.41 41.44 | 3.59 3.67 | | 1253-055 3C279 | 24.83 17.82 | 15.34 11.80 | 2.23 3.93 | | 1641+399 3C345 | 8.53 8.37 | 5.65 7.60 | 3.51 3.01 | | 1921-293 OV-236 | 11.67 14.43 | 10.00 4.60 | 3.00 1.04 | | 2134+004 2134+00 | 8.80 8.52 | 11.49 6.50 | 1.92 0.30 | | 2251+158 3C454.3 | 11.78 12.92 | 10.03 10.50 | 1.37 2.57 | |--------------------|----------------|--------------|--------------| where (1) IAU source name; (2) alias source name; (3) Flux in Jy at 8.0 GHz from UMRAO at the nearest date to 01-JUL-99; (4) Flux in Jy at 4.8 GHz from UMRAO at the nearest date to 01-JUL-99; (5) Flux in Jy at 6 cm from ICRF physical characteristics; (6) Flux in Jy at 15 cm from ICRF physical characteristics; (7) SPX: degree of polarization at 8.0GHz in percents taken from UMRAO at the nearest date to 01-JUL-99; (8) SPX: degree of polarization at 4.8GHz in percents taken from UMRAO at the nearest date to 01-JUL-99; These 10 sources are taken for BRD01 experiment. "Fluxes" for RL scans are taken 10-times less than fluxes for RR scans. Frequencies: ============ 85% observations (225 scans) will be made in SX-frequency setup. Remaining observations will be made with B1, B2, B3, B4, B5, B6 frequency setups. The frequency setups B1, B2, B3, B4, B5, B6 are obtained from frequency setup SX by adding the constant in the range [-21,+8] MHz to all 14 frequencies of the individual videoconverters: |---------|---------|---------|---------|---------|---------|---------| | SX | B1 | B2 | B3 | B2 | B4 | B5 | |---------|---------|---------|---------|---------|---------|---------| | 8210.99 | 8208.99 | 8207.99 | 8205.99 | 8213.99 | 8216.99 | 8218.99 | | 8220.99 | 8218.99 | 8217.99 | 8215.99 | 8223.99 | 8226.99 | 8228.99 | | 8250.99 | 8248.99 | 8247.99 | 8245.99 | 8253.99 | 8256.99 | 8258.99 | | 8310.99 | 8308.99 | 8307.99 | 8305.99 | 8313.99 | 8316.99 | 8318.99 | | 8420.99 | 8418.99 | 8417.99 | 8415.99 | 8423.99 | 8426.99 | 8428.99 | | 8500.99 | 8498.99 | 8497.99 | 8495.99 | 8503.99 | 8506.99 | 8508.99 | | 8550.99 | 8548.99 | 8547.99 | 8545.99 | 8553.99 | 8556.99 | 8558.99 | | 8570.99 | 8568.99 | 8567.99 | 8565.99 | 8573.99 | 8576.99 | 8578.99 | | 2212.99 | 2211.99 | 2209.99 | 2206.99 | 2200.99 | 2198.99 | 2191.99 | | 2222.99 | 2221.99 | 2219.99 | 2216.99 | 2210.99 | 2208.99 | 2201.99 | | 2237.99 | 2236.99 | 2234.99 | 2231.99 | 2225.99 | 2223.99 | 2216.99 | | 2267.99 | 2266.99 | 2264.99 | 2261.99 | 2255.99 | 2253.99 | 2246.99 | | 2292.99 | 2291.99 | 2289.99 | 2286.99 | 2280.99 | 2278.99 | 2271.99 | | 2297.99 | 2296.99 | 2294.99 | 2291.99 | 2285.99 | 2283.99 | 2276.99 | |---------|---------|---------|---------|---------|---------|---------| Observing scenarios =================== * Scenario a ("band scan") A pair of sources: 0316+413, 0923+392 is observed from 182.10:00 till 182.12:15 and a pair of sources: 0923+392, 2251+158 is observed from 183.07:20 183.09:43. First two scans are made in RR then two scans in RL, then frequencies of individual videoconverters are changed. Frequencies are changed 6 times by adding an offset to all frequencies of videoconverters with respect to initial (default) setup each time. Sequence of offsets at X-band is -2, -3, -5, +3, +6, +8 MHz and -1, -3, -6, -12, -14, -21 MHz at S-band. Restrictions: a) the frequencies of the individual vcs should not cross the boundary 224MHz of local oscillator: 8304 = 8080 + 224MHz and 2244 = 2020 + 224MHz in order not to change their setup: upper or lower was taken into account; b) the frequencies of the individual vcs should not exceed 499 MHz. * Scenario b ("pair connection") A pair of sources is observed. Two observations in RR and two observations in RL. Then the procedure is repeated. Pair 1226+023, 1253-055 is observed at 182.12:44 -- 182.14:00 and at 182.16:44 182.17:33. Pair 0538+508, 0552+398 is observed between 182.14:06 and 182.16:44 * Scenario c ("stay on source") One source is observed, but polarization is swapped after each scan. 1253-055 is observed at the baseline MEDICINA/MATERA from 182.17:33 till 182.20:00 while WETTZELL is engaged for NEOS Intensive and temporarily does not observe BRD01. * Scenario d ("full coverage") All visible sources are observed during 2-3 hours, in normal geodetic fashion to achieve full sky coverage, but polarization setup is not changed during that period. Then polarization is swapped and then again 2-3 hours of observations. RR: 182.20:04 182.23:11, RL: 182.23:11 183.02:04, RR: 183.02:04 183.04:05, RL: 183.04:05 183.07:17 Comments: 1. Additional 1-1.5 minutes is added to allow an operator in MEDICINA to swap polarization. 2. 10 additional "pseudosources" with l at the end of their name are added to the schedule in order to distinguish RR and RL scans. Their fluxes are set 10 times smaller than the fluxes of their RR counterparts. 3. SNR threshold 40 is used in order to get sure detection for all RL scans and reliable estimates of group delays. Schedule ======== This schedule was generated manually using sked97 program. Extra 1.5 minutes were added for change of polarization. SNR goals are 40 at X-band and 40 at S-band for all baselines. Average predicted SNR at the subnetwork MEDICINA/MATERA/WETTZELL: |------------|------|---------------|------| | Source | Plrz | SNR(X) SNR(S) | Num | |------------|------|---------------|------| | 0316+413 | RR | 662 418 | 57 | | 0316+413 | RL | 62 41 | 63 | | 0538+508 | RR | 184 87 | 30 | | 0538+508 | RL | 24 13 | 15 | | 0552+398 | RR | 131 152 | 24 | | 0552+398 | RL | 19 25 | 13 | | 0923+392 | RR | 301 239 | 70 | | 0923+392 | RL | 36 27 | 60 | | 1226+023 | RR | 1098 823 | 72 | | 1226+023 | RL | 98 83 | 57 | | 1253-055 | RR | 675 274 | 57 | | 1253-055 | RL | 73 30 | 45 | | 1641+399 | RR | 233 156 | 33 | | 1641+399 | RL | 37 25 | 24 | | 1921-293 | RR | 298 257 | 10 | | 1921-293 | RL | 45 27 | 18 | | 2134+004 | RR | 245 166 | 30 | | 2134+004 | RL | 36 25 | 30 | | 2251+158 | RR | 33 239 | 48 | | 2251+158 | RL | 37 27 | 51 | |------------|------|---------------|------| Average predicted SNR at the baseline TIGOWTZL/WETTZELL over all observations: X-band: 525 S-band: 355 Procedures ========== The following frequency setups are used: SX, B1, B2, B3, B4, B5, B6 These setups, except the first are not standard. Procedure file should be generated by DRUDGE. Appendix A ========== Schedule for polarization change for station MEDICINA. Polarization should be set within the range: not before the left boundary of the range and not after the right boundary. ----|----------|----------------------------- N | Polariz. | Time range for change | ----|----------|----------------------------- 0) RCP [ ........ , 09:59:00 UTC 1) LCP [ 10:07:00 , 10:08:40 ] UTC 2) RCP [ 10:16:30 , 10:18:40 ] UTC 3) LCP [ 10:26:00 , 10:28:40 ] UTC 4) RCP [ 10:36:30 , 10:38:40 ] UTC 5) LCP [ 10:46:00 , 10:47:40 ] UTC 6) RCP [ 10:55:30 , 10:58:40 ] UTC 7) LCP [ 11:06:00 , 11:07:40 ] UTC 8) RCP [ 11:15:30 , 11:17:40 ] UTC 9) LCP [ 11:25:00 , 11:27:10 ] UTC 10) RCP [ 11:35:00 , 11:36:40 ] UTC 11) LCP [ 11:44:00 , 11:46:40 ] UTC 12) RCP [ 11:54:30 , 11:57:40 ] UTC 13) LCP [ 12:05:00 , 12:06:40 ] UTC 14) RCP [ 12:14:30 , 12:14:50 ] UTC 15) LCP [ 12:22:20 , 12:24:40 ] UTC 16) RCP [ 12:32:40 , 12:34:40 ] UTC 17) LCP [ 12:48:20 , 12:51:10 ] UTC 18) RCP [ 12:58:30 , 13:01:10 ] UTC 19) LCP [ 13:05:30 , 13:07:40 ] UTC 20) RCP [ 13:13:20 , 13:15:40 ] UTC 21) LCP [ 13:21:10 , 13:24:10 ] UTC 22) RCP [ 13:29:40 , 13:31:40 ] UTC 23) LCP [ 13:36:00 , 13:38:40 ] UTC 24) RCP [ 13:44:30 , 13:47:40 ] UTC 25) LCP [ 13:52:00 , 13:53:40 ] UTC 26) RCP [ 13:59:10 , 14:03:40 ] UTC 27) LCP [ 14:08:00 , 14:10:40 ] UTC 28) RCP [ 14:22:20 , 14:32:40 ] UTC 29) LCP [ 14:38:10 , 14:40:40 ] UTC 30) RCP [ 14:52:30 , 15:02:40 ] UTC 31) LCP [ 15:08:10 , 15:13:50 ] UTC 32) RCP [ 15:32:00 , 15:39:40 ] UTC 33) LCP [ 15:44:00 , 15:47:10 ] UTC 34) RCP [ 16:05:20 , 16:12:40 ] UTC 35) LCP [ 16:17:00 , 16:19:50 ] UTC 36) RCP [ 16:50:00 , 16:52:60 ] UTC 37) LCP [ 16:58:30 , 17:00:40 ] UTC 38) RCP [ 17:05:50 , 17:07:40 ] UTC 39) LCP [ 17:12:00 , 17:13:40 ] UTC 40) RCP [ 17:19:30 , 17:22:40 ] UTC 41) LCP [ 17:28:10 , 17:29:40 ] UTC 42) RCP [ 17:34:50 , 17:36:40 ] UTC 43) LCP [ 17:38:40 , 17:40:40 ] UTC 44) RCP [ 17:42:40 , 17:44:40 ] UTC 45) LCP [ 17:46:40 , 17:48:40 ] UTC 46) RCP [ 17:50:40 , 17:53:40 ] UTC 47) LCP [ 17:55:40 , 17:58:40 ] UTC 48) RCP [ 18:00:40 , 18:02:40 ] UTC 49) LCP [ 18:04:40 , 18:06:40 ] UTC 50) RCP [ 18:08:40 , 18:10:40 ] UTC 51) LCP [ 18:12:40 , 18:14:40 ] UTC 52) RCP [ 18:16:40 , 18:18:40 ] UTC 53) LCP [ 18:20:40 , 18:23:40 ] UTC 54) RCP [ 18:25:40 , 18:28:40 ] UTC 55) LCP [ 18:30:40 , 18:33:40 ] UTC 56) RCP [ 18:35:40 , 18:39:20 ] UTC 57) LCP [ 18:41:20 , 18:44:40 ] UTC 58) RCP [ 18:46:40 , 18:48:40 ] UTC 59) LCP [ 18:50:40 , 18:52:40 ] UTC 60) RCP [ 18:54:40 , 18:56:40 ] UTC 61) LCP [ 18:58:40 , 19:01:10 ] UTC 62) RCP [ 19:06:40 , 19:09:40 ] UTC 63) LCP [ 19:11:40 , 19:13:40 ] UTC 64) RCP [ 19:15:40 , 19:18:40 ] UTC 65) LCP [ 19:20:40 , 19:22:40 ] UTC 66) RCP [ 19:24:40 , 19:27:40 ] UTC 67) LCP [ 19:29:40 , 19:38:40 ] UTC 68) RCP [ 19:40:40 , 19:44:40 ] UTC 69) LCP [ 19:46:40 , 19:49:20 ] UTC 70) RCP [ 19:51:20 , 19:54:40 ] UTC 71) LCP [ 19:56:40 , 19:58:40 ] UTC 72) RCP [ 20:00:40 , 20:03:40 ] UTC 73) LCP [ 22:46:00 , 22:48:40 ] UTC 74) RCP [ 02:00:20 , 02:04:40 ] UTC 75) LCP [ 03:58:00 , 04:02:40 ] UTC 76) RCP [ 06:40:00 , 06:41:40 ] UTC 77) LCP [ 06:47:40 , 06:49:40 ] UTC 78) RCP [ 06:57:00 , 06:59:40 ] UTC 79) LCP [ 07:05:40 , 07:07:40 ] UTC 80) RCP [ 07:14:40 , 07:16:40 ] UTC 81) LCP [ 07:22:40 , 07:24:40 ] UTC 82) RCP [ 07:33:10 , 07:36:40 ] UTC 83) LCP [ 07:43:50 , 07:47:40 ] UTC 84) RCP [ 07:55:30 , 07:58:60 ] UTC 85) LCP [ 08:06:10 , 08:09:40 ] UTC 86) RCP [ 08:17:20 , 08:20:40 ] UTC 87) LCP [ 08:27:50 , 08:31:40 ] UTC 88) RCP [ 08:39:20 , 08:42:40 ] UTC 89) LCP [ 08:49:50 , 08:53:40 ] UTC 90) RCP [ 09:01:30 , 09:05:40 ] UTC 91) LCP [ 09:12:50 , 09:16:40 ] UTC 92) RCP [ 09:24:30 , 09:28:40 ] UTC 93) LCP [ 09:35:40 , 09:39:40 ] UTC 94) RCP [ 09:47:20 , 09:49:40 ] UTC 95) LCP [ 09:51:40 , 09:53:40 ] UTC 96) RCP [ 09:55:40 , 09:57:40 ] UTC Appendix B ========== SKED Summary from file for experiment BRD01 (all scans with at least one subnet station) Average number of obs. per baseline per source (normalized by up-time) = 24.2 Min = 3.7 Max = 51.0 (Baseline Tg-Wz on 1226+023) RMS = 12.5 Total time: 1439 minutes ( 24.0 hours). Key: Ma=MATERA Mc=MEDICINA Tg=TIGOWTZL Wz=WETTZELL Ma Mc Tg Wz Avg % obs. time: 47 34 28 48 39 % cal. time: 3 3 3 3 3 % slew time: 11 26 6 7 12 % idle time: 38 36 61 41 44 # of tapes : 2.6 1.7 .4 .7 total # scans: 268 273 270 272 270 # scans/hour : 11 11 11 11 11.3 Avg scan (sec): 151 107 90 154 125 # OF OBSERVATIONS BY BASELINE | Ma Mc Tg Wz StnTotal ------------------------------ Ma|268 268 265 267 803 Mc| 273 270 272 807 Tg| 270 270 802 Wz| 272 812 Number of 2-station scans: 1 Number of 3-station scans: 7 Number of 4-station scans: 265 Total # of scans, observations: 273 1612 Average baseline components for all observations Average XY = 455. Average XZ = 525. Average YZ = 481. Average length = 602.