Session Notes for rd1405 (OCEL01) - prepared by Ruediger Haas =============================================================== PURPOSE AND GENERAL NOTES =============================================================== ===> OCEL - Observations of the Chang'E-3 lander with VLBI <=== This information is distributed via email to Badary: Elena Skurikhina HartRAO: Jonathan Quick Hobart: Jim Lovell Medicina: Carlo Stanghellini Ny-AAlesund: Moritz Sieber Onsala: Rudiger Haas Westford: Mike Poirier Wettzell: Christian Plštz , Alexander Neidhardt Shanghai: Xia Bo Zelenchukskaya: Elena Skurikhina NASA/NVI: "Behrend, Dirk (GSFC-698.0)[NVI INC]" , "Cynthia C. Thomas" UBonn: Axel Nothnagel , Alessandra Bertarini BAAC: Tang Geshi Tang Geshi and several co-PIs proposed in May 2014 to observe the Chinese Lunar Lander Chang'E-3 with VLBI. This proposal was accepted by the IVS PC and a series of RD-sessions was allocated for this purpose. The scheduling is done by R. Haas (Chalmers University of Technology, Sweden), the Lunar Lander apriori positions are provided by Tang Gesh (BAAC, China), the primary correlation will be done by the Bonn correlator and special correlation issues will be looked into by the correlators at BAAC (China) and Onsala (Sweden). The data will be analyzed by the proposing consortium (PIs), and the data have a one year data hold. The first OCEL-session is on July 8/9 when the Chang'E-3 lander will be actively sending on several X-band channels, among them a data channel and several DOR tones. However, the lander will only be active during the session on July 8, 17:30-19:30 UT and July 9, 09:00-17:30 UT. During the remaining hours of the session the lander will not be sending. The scheduling is by far different from 'normal scheduling' and was done with SKED and manual interaction. Several blocks of geodetic scheduling, lunar lander observations, and phase referencing between the lunar lander and radio sources were scheduled: July 8 17:30-18:00 geodetic scheduling 18:00-18:15 lunar lander observations 18:15-18:45 phase referencing lunar lander - radio source 18:45-19:00 geodetic scheduling 19:00-19:30 phase referencing lunar lander - radio source July 8 19:30-09:00 on July 9 geodetic scheduling July 9 09:00-09:10 geodetic scheduling 09:10-09:30 lunar lander observations 09:30-09:50 phase referencing lunar lander - radio source 09:50-10:10 geodetic scheduling 10:10-10:30 phase referencing lunar lander - radio source 10:30-10:50 lunar lander observations 10:50-11:10 geodetic scheduling 11:10-11:30 lunar lander observations 11:30-11:50 phase referencing lunar lander - radio source 11:50-12:10 geodetic scheduling 12:10-12:30 phase referencing lunar lander - radio source 12:30-12:50 lunar lander observations 12:50-13:10 geodetic scheduling 13:10-13:30 lunar lander observations 13:30-13:50 phase referencing lunar lander - radio source 13:50-14:10 geodetic scheduling 14:10-14:30 phase referencing lunar lander - radio source 14:30-14:50 lunar lander observations 14:50-13:10 geodetic scheduling 15:10-15:30 lunar lander observations 15:30-15:50 phase referencing lunar lander - radio source 15:50-16:10 geodetic scheduling 16:10-16:30 phase referencing lunar lander - radio source 16:30-16:50 lunar lander observations 16:50-17:10 geodetic scheduling 17:10-17:20 lunar lander observations 17:20-17:30 phase referencing lunar lander - radio source The station network consists of 10 stations: Badary, HartRAO, Hobart26, Medicina, Nyales20, Onsala60, Seshan25, Westford, Wettzell, Zelenchk Ny-AAlesund cannot see the lunar lander throughout the whole experiment, and Westford cannot see the lunar lander when it is sending. Thus these two stations do not have any lunar lander observations. Wettzell will observe en INT-session on 8 July, 20:15-21:45. The schedule files are provided in form of individual vex-files. The files are individual per station since the lunar lander has slightly different apriori ra/dec coordinates as seen from the different participating stations, since the Moon is in the near field. The vex files are rd1405_bd.vex rd1405_hh.vex rd1405_ho.vex rd1405_mc.vex rd1405_ny.vex rd1405_on.vex rd1405_sh.vex rd1405_wf.vex rd1405_wz.vex rd1405_zc.vex The stations should use their individual vex file, copy it to the name rd1405.vex and then drudge it in order to produce snap-file and procedure-file. There might though be some complaints by drudg, however, the resulting snp and prc-files should be correct and working. There are two different setups for those stations that observe the lunar lander, setup01 and setup02. The first setup is a standard setup usually used for R1-sessions, while the second setup is the special lunar lander setups. For the latter, the X-band frequencies are modified in order to correspond to the lunar lander sending frequencies. All lunar lander center frequencies are between 8450 MHz and 8496 MH, with bandwidth of 2 to 5 MHz. The data channel with center frequency 8496 MHz is rather strong with an EIRP of about 16 W. The DOR channels are located at 8470 MHz and tones at +/- 19.2 MHz and +/- 3.85 MHz and these channels have an EIRP of about 1 W. Due to the rather strong signals, the received signal strength is on the order of 20-40 dB stronger than normal natural radio sources. Thus, additional attenuation has to be implemented in the lunar lander setup. Stations with Mark4 racks should prepare to add on the order of 20-40 dB, and then monitor and adapt the attenuation correspondingly. This can be done in the beginning of the experiment during the first 15 minutes with lunar lander observations. The frequency distribution for the lunar lander observations is as follows: BBC 3 8465.99 MHz (DOR central tone) BBC 4 8491.99 MHz (Data channel) BBC 5 8446.99 MHz (DOR - 19.2 MHz) BBC 6 8461.99 MHz (DOR - 3.85 MHz) BBC 7 8465.99 MHz (DOR central tone) BBC 8 8485.99 MHz (DOR + 19.2 MHz) This frequency distribution should make it possible to individually set attenuation for the stronger signals in BBC 3 and BBC (in particular BBC 4) and the other 4 BBCs. An approximate summary of the session is given below. The amount of data to be recorded is just on the order of 1 TB per station. The stations should transfer (e- or ship) the data to the Bonn correlator after the session is done. SKED Summary from file /home/mk5_2014/sched/ocel01.skd for experiment OCEL01 (all scans with at least one subnet station) Calculating rise/set times: 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74... done. Average number of obs. per baseline per source(normalized by up-time) = 9.3 Min = 0.0 Max = 514.3 (Baseline Bd-Wz on OCEL.01 ) RMS = 32.6 Total time: 1441 minutes ( 24.0 hours). Key: Ny=NYALES20 Sh=SESHAN25 Wf=WESTFORD Bd=BADARY Hh=HARTRAO Ho=HOBART26 Mc=MEDICINA Zc=ZELENCHK On=ONSALA60 Wz=WETTZELL Ny Sh Wf Bd Hh Ho Mc Zc On Wz Avg % obs. time: 36 39 34 29 23 24 35 25 42 28 32 % cal. time: 4 5 3 5 3 4 4 4 4 4 4 % slew time: 20 25 11 47 40 32 32 46 22 9 29 % idle time: 38 30 51 18 33 39 28 23 31 58 36 total # scans: 347 404 270 404 265 319 347 382 327 368 343 # scans/hour : 14 17 11 17 11 13 14 16 14 15 14 Avg scan (sec): 91 84 110 62 76 64 88 57 110 65 79 # data tracks: 16 16 16 16 16 16 16 16 16 16 # Mk5 tracks: 16 16 16 16 16 16 16 16 16 16 Total TBytes: 1.1 1.2 1.1 0.9 0.7 0.7 1.1 0.8 1.3 0.9 1.0 Total TB(M5): 1.0 1.1 0.9 0.8 0.6 0.7 1.0 0.7 1.1 0.8 0.9 # OF OBSERVATIONS BY BASELINE | Ny Sh Wf Bd Hh Ho Mc Zc On Wz Total ------------------------------------------------------------ Ny| 170 222 227 38 31 235 225 247 242 1637 Sh| 112 319 107 232 178 213 161 173 1665 Wf| 137 31 11 186 141 199 181 1220 Bd| 103 161 202 271 189 210 1819 Hh| 147 126 151 97 122 922 Ho| 42 79 20 42 765 Mc| 278 302 322 1871 Zc| 247 297 1902 On| 288 1750 Wz| 1877 Number of 2-station scans: 230 Number of 3-station scans: 140 Number of 4-station scans: 72 Number of 5-station scans: 101 Number of 6-station scans: 43 Number of 7-station scans: 89 Number of 8-station scans: 102 Number of 9-station scans: 7 Number of 10-station scans: 0 Total number of scans: 784 Total number of obs: 7714 Total integrated obs-time: 530508 Average obs-time: 68.8 ===========================================================