Session Notes for rd1407 (OCEL02) - 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 Andrey G. Mikhailov HartRAO: Jonathan Quick Matera: Giovanni Nettis Ny-AAlesund: Moritz Sieber VLBI Ny-lesund Shanghai: Xia Bo Wettzell: Christian Plštz Alexander Neidhardt RT-20m Wettzell Urumqi: Wengjun Yan Xiang Liu Zelenchukskaya: Elena Skurikhina Andrey G. Mikhailov NASA/NVI: "Behrend, Dirk (GSFC-698.0)[NVI INC]" , "Cynthia C. Thomas" Ed Himwich UBonn: Axel Nothnagel , Alessandra Bertarini Laura la Porta BAAC: Tang Geshi Onsala: RŸdiger Haas 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 2nd OCEL-session is on September 10/11 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 parts of the 24 h session. During the active period of the lander, alternating geodetic and phase-referencing observations will be performed, in intervals of 20 min each. The schedule looks basically as follows: 18:00-18:30 geodetic 18:30-19:00 phase-referencing lunar lander - radio sources 19:00-19:30 geodetic 19:30-20:00 phase-referencing lunar lander - radio sources . . and so on until 02:00 . . 02:00-14:00 geodetic 14:00-14:30 phase-referencing lunar lander - radio sources 14:30-15:00 geodetic 15:00-16:30 phase-referencing lunar lander - radio sources 15:30-16:00 geodetic . . and so on until the end of the session at 18:00 The station network consists of 8 stations: Badary, HartRAO, Matera, Nyales20, Seshan25, Urumqi, Wettzell, Zelenchk The schedule files were 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 rd1407_BADA_140910.vex rd1407_HART_140910.vex rd1407_MATE_140910.vex rd1407_NYAL_140910.vex rd1407_SESH_140910.vex rd1407_URUM_140910.vex rd1407_WETT_140910.vex rd1407_ZELE_140910.vex The stations should use their individual vex file, copy it to the name rd1407.vex and then drudg it in order to produce snap-file and procedure-file. The FS version 9.11.6 appears necessary. There might though be some complaints by drudg, however, the resulting snp and prc-files should be correct and working. Stations that do not have FS 9.11.6 can get assistance by Ed Himwich who can provide them with the necessary *.snp and *.prc files. There are three setups in the session, setup01, setup02 and setup03. The first setup is a standard setup usually used for narrow-band T2-sessions, while the second setup and third setups are special lunar lander setups. For the latter two, the X-band frequencies are modified in order to correspond to the lunar lander sending frequencies. There are setup02 and setup03 in order to make it possible for stations that do not have automatic gain control, to use special and individual attenuation when observing the lunar lander and natural radio sources in phase-referencing mode. 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 10-30 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 10-30 dB, and then monitor and adapt the attenuation correspondingly. This can be done in the beginning of the experiment when the first observations of the lunar lander signals are performed. The frequency distribution for the lunar lander observations is as follows: BBC 1 8448.99 MHz (DOR - 19.2 MHz) BBC 2 8463.99 MHz (DOR - 3.85 MHz) BBC 3 8467.99 MHz (DOR central tone) BBC 4 8471.99 MHz (DOR + 3.85 MHz) BBC 5 8486.99 MHz (DOR + 19.2 MHz) BBC 6 8493.99 MHz (Data channel) BBC 7 8468.99 MHz (DOR central tone + 1 Mhz) BBC 8 8494.99 MHz (Data channel + 1 MHz) An approximate summary of the session is given below. The amount of data to be recorded is just less than 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/ocel02.skd for experiment OCEL02 (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) = 8.6 Min = 0.0 Max = 148.4 (Baseline Bd-Ur on OCEL.02 ) RMS = 16.6 Total time: 1439 minutes ( 24.0 hours). Key: Ny=NYALES20 Sh=SESHAN25 Bd=BADARY Hh=HARTRAO Zc=ZELENCHK Ma=MATERA Ur=URUMQI Wz=WETTZELL Ny Sh Bd Hh Zc Ma Ur Wz Avg % obs. time: 40 42 27 21 22 42 44 37 34 % cal. time: 4 4 5 2 5 4 4 4 4 % slew time: 17 25 51 30 51 26 26 10 30 % idle time: 38 28 16 46 21 28 24 47 31 total # scans: 344 358 457 183 422 342 378 386 358 # scans/hour : 14 15 19 8 18 14 16 16 15 Avg scan (sec): 100 100 50 97 45 105 101 82 84 # data tracks: 16 16 16 16 16 16 16 16 # Mk5 tracks: 16 16 16 16 16 16 16 16 Total TBytes: 0.6 0.6 0.4 0.3 0.3 0.6 0.7 0.6 0.5 Total TB(M5): 0.5 0.6 0.4 0.3 0.3 0.6 0.6 0.5 0.5 # OF OBSERVATIONS BY BASELINE | Ny Sh Bd Hh Zc Ma Ur Wz Total -------------------------------------------------- Ny| 217 266 61 282 245 274 278 1623 Sh| 340 80 219 163 304 193 1516 Bd| 74 308 208 351 256 1803 Hh| 123 118 67 116 639 Zc| 273 256 327 1788 Ma| 221 296 1524 Ur| 245 1718 Wz| 1711 Number of 2-station scans: 157 Number of 3-station scans: 164 Number of 4-station scans: 69 Number of 5-station scans: 41 Number of 6-station scans: 75 Number of 7-station scans: 115 Number of 8-station scans: 41 Total number of scans: 662 Total number of obs: 6161 Total integrated obs-time: 420797 Average obs-time: 68.3 ===========================================================