Mars Express Bistatic Radar Experiment Operations Plan and Report 14 August 2009 Summary ======= DSN Antenna: 14 Pass: 2267 Orbit: 7204 Orbit Start Time: 2009-08-14T10:34:48 HGA Pointing: Specular Start Center End -------- ---------- -------- Specular Condition (ERT): 12:52 13:26 14:00 Target Latitude (deg N): 46.46 59.38 47.91 Longitude (deg E): 287.79 304.24 355.50 Rp (km): 3394. 3394. 3394. Incidence/Reflection Angle (deg): 72.21 66.69 51.22 Slant Range (km): 8454. 5437. 1422. Slew Angle (deg): 35.58 46.61 77.57 Doppler (carrier, fd; Hz): 39992. 54874. 51240. Doppler (echo, fr; Hz): 37378. 55166. 71751. Doppler Difference (fdd; Hz): 2614. -292. -20511. Earth-Mars Distance (m): 2.541E+11 2.541E+11 2.541E+11 Experiment Set Up ================= This experiment was conducted using Goldstone's DSS 14. Danny Kahan and Gene Goltz were in the Radio Science Support Area (RSSA) at JPL. Dick Simpson was available by phone. Performance Problems and Notes ============================== The S-LCP data are very noisy; switching to the ambient load added only 4.5 dB in the pre-cal and post-cal, rather than the expected 11 dB. The problem persisted through all subsequent DSS 14 BSR experiments in 2009. In January 2010 the 'CNV' board in RSR3 was replaced, and tests on 21 January 2010 confirmed that normal performance had been restored. The post-BSR S-LCP mini-cal was not successful -- the noise diode was never turned on. Data Acquisition ================ RSRs were configured as in Table 1. Table 1 ---------------------------------------------------- RSR Channel Mode ATT FGAIN Operator dB ----- ------- ---- ---- ----- ---------------------- RSR3A S-LCP 1-W auto 60 UNK RSR3B X-LCP 1-W auto 60 UNK RSR2A S-RCP 1-W auto 60 UNK RSR2B X-RCP 1-W auto 60 UNK RSR subchannels (SCHAN) were defined as follows: Table 2 ---------------------------------------------------------------------- Subchannel Sample Rate Comments ---------- ----------- --------------------------------------------- 1 2 ksps Occultation bandwidth (not recorded for BSR) 2 8 ksps Occultation backup (not recorded for BSR) 3 25 ksps Primary recording bandwidth 4 100 ksps Backup recording Table 3 lists ADC amplitude levels read from RSR displays during the experiment. Times are in UTC and should be considered approximate. "Steps" are as defined in the briefing message. RSR ATT settings are in units proportional to dB. Acronyms and abbreviations are explained after Table 3. Table 3 ----------------------------------------------------------------------------- Activity Time Step # S-LCP X-LCP S-RCP X-RCP Notes / Comments 2009/226 RSR3A RSR3B RSR2A RSR2B -------- ----- --------- ----- ----- ----- ----- ------------------------ fgain 08:10 60 60 60 60 GAIN = 60 dB Pre-Ca 08:55 1 -4.3 -12.6 -6.0 -11.8 08:58 att auto -10.3 -9.8 -10.2 -9.8 ADC amplitudes (dB) 19.5 12.0 5.0 10.0 Attenuator settings (dB) 09:00 2 -10.3 -0.2 -10.2 0.1 ADC amplitudes (dB) 09:02 3 -3.2 -0.1 10.1 0.1 09:04 4 -3.4 -0.1 -0.7 0.1 09:06 att auto 26.5 24.0 15.5 22.5 Reset attenuators (dB) -9.9 -9.7 -9.7 -9.7 ADC amplitudes (dB) AMB load phys temps S1=19.19 S2=24.25 X1=15.88 Local weather: T=22.2C H=27.8 percent sky=clear 09:07 rec 3 e Begin 25 kHz recording 09:07 5 -9.9 -9.7 -9.6 -9.6 ADC amplitudes (dB) 09:15 6 -9.8 -9.7 -9.6 -9.5 09:20 7 -9.8 -21.8 -9.7 -20.0 09:25 8 -9.7 -21.8 -9.6 -22.4 09:30 9 -9.8 -19.6 -9.7 -22.4 Confirm 12.5K ND 09:35 10 -9.8 -9.5 -9.6 -9.8 AMB load phys tems: S1=18.18 S2=23.75 X1=15.56 09:40 11 -9.7 -9.7 -9.7 -9.8 09:45 12 -9.8 -21.8 -9.5 -22.4 09:50 13 -9.7 -21.8 -9.4 -22.4 09:55 14 -9.7 -21.9 -18.9 -22.3 10:00 15 -9.8 -21.9 -20.7 -22.3 Confirm 12.5K ND 10:05 16 -9.6 -21.9 -20.9 -22.4 10:10 17 -15.6 -21.8 -20.8 -22.2 10:15 18 -17.3 -21.9 -20.8 -22.2 AMB load phys temps: S1=18.31 S2=23.06 X1=15.19 10:20 end -17.6 -21.9 -20.7 -22.4 Stop 25 kHz recording BOT 10:30 -17.1 -20.8 -20.0 -21.1 Collect TLM to 12:15 12:30 rec 3 e -9.6 -21.5 -20.5 -21.7 Resume 25 kHz recording 12:35 -13.9 -21.5 -20.5 -20.4 Switch DSS 14 to Mars pointing predicts 12:37 sfro 3 +24K +23K +24K +23K Rcvr tuning offset (Hz) MiniCal1 12:37 1 -12.0 -21.6 -20.6 -18.6 Confirm 12.5K ND 12:40 2 -13.8 -21.6 -18.7 -20.3 12:43 3 -14.5 -19.5 -20.6 -20.3 12:46 4 -15.3 -21.5 -20.7 -20.6 12:49 5 -14.1 -21.6 -20.6 -20.6 12:52 end -15.2 -21.5 -20.5 -20.5 BSR 12:52 sfro 3 0 -6K 0 -6K Rcvr tuning offsets (Hz) Begin 100 kHz recording 13:35 sfro 3 0 0 Rcvr tuning offsets (Hz) 13:46 sfro 3 +6K +6K Rcvr tuning offsets (Hz) 13:54 sfro 3 +12K +12K Rcvr tuning offsets (Hz) END BSR 14:00 sfro 3 +24K +23K +24K +23K Rcvr tuning offsets (Hz) End 100 kHz recording MiniCal2 14:04 1 -10.6 -21.6 -20.7 -19.7 Confirm 12.5K ND 14:07 2 -11.1 -21.6 -18.6 -22.1 ADC amplitudes (dB) 14:10 3 -13.8 -19.4 -20.7 -22.2 14:13 4 -15.7 -21.7 -20.7 -22.2 14:16 5 -14.8 -21.7 -20.7 -22.2 14:19 end -15.3 -21.8 -20.7 -22.1 14:19 sfro 3 0 0 0 0 Rcvr tuning offsets (Hz) 14:20 -13.1 -21.6 -20.7 -22.0 Switch DSS 14 to S/C pointing predicts 14:32 rec 3 d -11.0 -21.7 -20.6 -20.4 Stop 25 kHz recording EOT 15:00 -12.2 -21.7 -20.6 -20.6 Move DSS 14 to stow Post-Cal 15:02 rec 3 e -15.8 -21.8 -20.7 -22.3 Resume 25 kHz recording 15:08 1 -9.9 -9.7 -9.5 -9.7 AMB load phys temps: S1=17.38 S2=21.69 X1=14.94 15:15 2 -9.9 -9.6 -9.5 -9.6 ADC amplitudes (dB) 15:18 3 -9.8 -9.8 -9.4 -9.7 15:21 4 -9.8 -9.5 -9.6 -9.6 15:24 5 -9.7 -9.7 -9.5 -9.7 15:27 6 -15.3 -21.9 -20.7 -22.3 15:30 7 -16.8 -19.5 -20.6 -19.8 15:33 8 -16.7 -21.8 -18.7 -22.1 15:36 9 -16.0 -22.0 -20.5 -19.8 15:39 10 -16.0 -21.9 -20.6 -22.2 AMB load phys temps: S1=17.62 S2=21.88 X1=14.94 Local weather: T=23.7C H=32.9 percent sky=clear 15:42 end -15.9 -21.9 -20.6 -22.4 End 25 kHz recording AMB = ambient load BOT = Beginning of Track CNR = Carrier to noise ratio CONSCAN = conical scan tracking CW = continuous wave (carrier only) EOA = End of activity EOT = End of Track FRO = frequency offset HGA = high-gain antenna LOS = loss of signal ND = noise diode No = noise power Pc = carrier power rcvr = receiver S1 = ambient load for S-RCP S2 = ambient load for S-LCP SL = S-LCP SNR = Signal to noise ratio SR = S-RCP TLM = telemetry X1 = Ambient load for both X-band channels XL = X-LCP XR = X-RCP Post-Analysis Summary The table below summarizes the time division of X-Band data so as to capture the echo power as the signal drifted through the 25 kHz receiving passband. Power estimates were made from 10-second average spectra. Int Times Spectra Noise Bins Carrier Echo Notes Bins Bins --- ----------------- ------- --------------- ------- ------- -------- A 12:52:00-13:17:00 001-150 104:446,631:916 618:623 451:615 B 13:17:00-13:29:30 151-225 104:512,717-916 618:623 518:712 [1] C 13:29:30-13:34:58 226-258 104:614,818:916 618:623 628:815 CD 13:34:58-13:35:08 259 104:370,818:916 374:379 446:815 [2] D 13:35:08-13:45:58 260-324 104:370,818:916 374:379 446:815 DE 13:45:48-13:46:08 325 133:370,818:916 374:379 430:815 [3] 127:132 E 13:46:08-13:53:57 326-372 133:420,860:916 127:132 430:855 EF 13:53:57-13:54:07 373 133:420,860:916 127:132 430:855 [4] F 13:54:07-13:59:57 374-408 104:420,860:916 --- 430:855 [5] Notes: [1] Used carrier suppression to estimate echo power [2] X-Band tuning offset (FRO) at 13:35 [3] X-Band tuning offset (FRO) at 13:46 [4] X-Band tuning offset (FRO) at 13:54 [5] The carrier was outside the recorded pass band after 13:54 For S-Band, the tables below summarizes the processing of 10-second average spectra. Int Times Spectra Noise Bins Carrier Echo Notes Bins Bins --- ----------------- ------- --------------- ------- ------- -------- A 12:52:00-13:13:00 001-126 104:369,460:916 451:455 375:447 B 13:13:00-13:32:00 127-240 104:409,501:916 451:455 414:497 [1] C 13:32:00-14:00:00 241-408 104:450,778:916 451:455 [2] Notes: [1] Used carrier suppression to estimate echo power [2] Used linearly drifting window to estimate echo power, starting at 457:497 and ending at 532:774 For S-Band, the tables below summarizes the processing of 60-second average spectra. Int Times Spectra Noise Bins Carrier Echo Notes Bins Bins --- ----------------- ------- --------------- ------- ------- -------- A 12:52:00-13:13:00 001-021 104:398,460:916 451:455 401:455 B 13:13:00-13:32:00 022-040 104:409,501:916 451:455 414:497 [1] C 13:32:00-14:00:00 041-068 104:450,778:916 451:455 [2] Notes: [1] Used carrier suppression to estimate echo power [2] Used linearly drifting window to estimate echo power, starting at 457:497 and ending at 532:774 Dick Simpson Original: 2009-10-10 Updated geometry summary: 2009-11-02 Added Post-Analysis Summary: 2009-11-23 Updated S-LCP noise status under Performance Problems and Notes: 2010-06-30