Mars Express Bistatic Radar Experiment Operations Plan and Report 24 June 2006 Summary ======= DSN Antenna: 43 Pass: 1120 Orbit: 3152 Orbit Start Time: HGA Pointing: Specular Start Phoenix B End -------- ---------- -------- Specular Condition (ERT): 05:49:50 06:21:00 06:51:00 Target Latitude (deg N): 49.58 68.18 -8.44 Longitude (deg E): 82.75 131.12 183.13 Rp (km): 3394. 3394. 3394. Incidence/Reflection Angle (deg): 51.86 49.48 67.47 Slant Range (km): 5143. 1995. 994. Slew Angle (deg): 76.28 81.04 45.07 Doppler (carrier, fd; Hz): 20558 5231 -44901 Doppler (echo, fr; Hz): 45381 47068 -52044 Doppler Difference (fdd; Hz): -24824 -41837 7143 Earth-Mars Distance (m): 3.461E+11 3.461E+11 3.461E+11 Experiment Set Up ================= This experiment was conducted using Canberra's DSS 43. Gene Goltz, Danny Kahan, and Dick Simpson were in the Radio Science Support Area at JPL; Jose Valencia was in the NOPE area. For the most part, Kahan operated the RSR's and Goltz handled communications. Performance Problems and Notes ============================== S-LCP and S-RCP inputs to the RSR's were swapped. This has been "standard" at DSS 43 for several months. The problem will be investigated during regular maintenance next Tuesday. The S-RCP noise diode was turned on very early in the pre-cal. As a result, the only useful data are in the AMB+ND configuration. This makes the Top value from the pre-cal worthless and compromises the pre-cal estimate of the S-RCP noise diode power. At the end of the pre-cal (Step 13, executed at 03:21:05) the X-RCP noise diode was incorrectly set to MFQ=20 rather than MFQ=ON. This cut its power roughly in half during MiniCal #1, leading to an incorrect estimation of the X-RCP system temperature immediately before the BSR. There were convincing X-RCP and X-LCP echoes 3 minutes before the BSR interval officially began at 05:50 (>20 dB/Hz spread over 2 kHz). The X-RCP echo faded and didn't return in any convincing fashion until about 06:30. The X-LCP echo was broad (2-5 kHz), fading in and out but generally present throughout. At 06:40 the first of half a dozen very strong echoes were observed in both X-RCP and X-LCP; these reached strengths >30 dB/Hz and lasted 30-60 seconds each. They were still in progress when the spacecraft transmitters were turned off at 6:51. Presumably there are some very smooth surfaces between (30N, 187E) and (8S, 183E). There were no real-time signs of S-Band echoes at any time during the experiment. Data Acquisition ================ RSRs were configured as in Table 1. Note that the S-Band polarizations are swapped compared with the nominal configuration; but this has been the case for several months at DSS 43. Table 1 ---------------------------------------------------- RSR Channel Mode ATT FGAIN Operator dB ----- ------- ---- ---- ----- ---------------------- RSR1A S-RCP 1-W auto 60 Kahan RSR1B X-LCP 1-W auto 60 Kahan RSR2A S-LCP 1-W auto 60 Kahan RSR2B X-RCP 1-W auto 60 Kahan RSR subchannels (SCHAN) were defined as follows: Table 2 ---------------------------------------------------------------------- Subchannel Sample Rate Comments ---------- ----------- --------------------------------------------- 1 2 ksps backup (not recorded) 2 8 ksps backup (not recorded) 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-RCP X-LCP S-LCP X-RCP Notes / Comments RSR1A RSR1B RSR2A RSR2B -------- ----- --------- ----- ----- ----- ----- ------------------------ 2006/175 -------- Pre-Cal 02:32 1 -10.1 -9.8 -9.8 -9.7 All to sky (dB) 2.0 12.0 9.0 12.5 ATT settings 02:34 2 -10.1 -0.0 -9.8 0.1 X-Band to AMB 02:35 3 -10.2 -0.0 -0.4 0.0 S-LCP to AMB 02:36 4 -0.4 -0.0 -0.3 0.0 S-RCP to AMB 02:37 -9.8 -10.0 -9.8 -9.8 After ATT AUTO reset 13.5 25.5 20.5 25.0 ATT settings 02:38 Begin 25 kHz recording AMB load physical temps: S1=20.56C S2=20.56C X1=20.0C Weather conditions: T=9C H=65.7 percent sky=clear 02:39 5 -9.7 -9.9 -9.8 -9.8 Configure DTT01, DTT02 02:45 6 -9.6 -10.0 -9.8 -9.0 XR ND ON 02:50 7 -9.8 -22.2 -9.8 -15.7 X-Band to sky 02:55 8 -9.7 -22.2 -10.0 -22.5 XR ND OFF 03:00 9 -9.7 -17.0 -9.9 -22.3 XL ND ON Confirmed using 12.5K ND 03:05 10 -9.8 -9.4 -9.9 -9.8 X-Band to AMB AMB load physical temps: S1=20.75 S2=20.62 X1=19.69 03:10 11 -9.7 -10.0 -9.9 -9.9 XL ND OFF 03:15 12 -9.8 -22.2 -9.8 -22.2 X-Band to sky 03:20 13 -9.7 -22.2 -9.8 -22.2 S-RCP ND ON 03:21 X-RCP ND set to MFQ=20 03:25 14 -19.5 -22.2 -9.9 -22.2 S-RCP to sky 03:30 15 -21.8 -22.2 -9.8 -22.2 SR ND OFF Confirmed using 12.5K ND 03:35 16 -21.9 -22.3 -9.6 -22.1 SL ND ON 03:40 17 -21.9 -22.2 -18.6 -22.2 S-LCP to sky 03:45 18 -21.9 -22.2 -21.3 -22.2 SL ND OFF 03:50 end Stop 25 kHz recording AMB load physical temps: S1=21.00 S2=20.81 X1=19.44 BOT/AOS 03:57 56.2 Carrier to noise (dB/Hz) -200 3-W carrier offset (Hz) 04:20 DSS43 X-RCP in lock 57.9 Carrier to noise (dB/Hz) 1881 3-W carrier offset (Hz) 04:36 DSS43 S-RCP in lock 43.2 22.9 -- 58.0 Carrier to noise (dB/Hz) 275 3024 -- 3040 3-W carrier offset (Hz) 04:45 Carrier now 1-way 42.9 23.4 -- 58.1 Carrier to noise (dB/Hz) -1236 -2534 -- -2542 Carrier offset (Hz) 04:50 Begin 25 kHz recording 04:51 -21.6 -21.8 -20.8 -20.7 ADC amplitude 42.9 30.5 -- 65.3 CNR (dB/Hz) (TLM OFF) -1272 -2676 -- -2680 Carrier offset (Hz) 05:07 -21.6 -21.7 -20.9 -20.7 ADC amplitude (dB) 42.9 34.2 -- 65.4 Carrier to noise (dB/Hz) -1352 -2957 -- -2955 Carrier offset (Hz) SLEW1 05:20 Begin Slew #1 -21.6 -21.7 -20.7 -20.8 ADC amplitude (dB) 42.7 23.4 -- 58.2 Carrier to noise (dB/Hz) -1387 -3086 -- -3088 Carrier offset (Hz) 05:25 FRO 3600 25000 3600 25000 SCHAN 3 FRO entered (Hz) FRO 0 18000 0 18000 SCHAN 4 FRO entered (Hz) MINICAL1 05:30 1 -21.5 -21.8 -20.9 -17.2 XR ND ON 05:33 2 -19.1 -21.7 -20.7 -20.8 XR ND OFF; SR ND ON 05:36 3 -21.5 -17.0 -20.7 -20.9 SR ND OFF; XL ND ON 05:39 4 -21.5 -21.7 -18.4 -20.9 XL ND OFF; SL ND ON 05:42 5 -21.5 -21.7 -20.6 -20.8 SL ND OFF 05:45 end BSR 05:47 XL, XR echo at -5000 Hz 05:50 Begin 100 kHz recordings 06:00 FRO 31000 31000 SCHAN 3 FRO change (Hz) 21.7 19.0 Echo to noise (dB/Hz) -3918 Echo center offset (Hz) 06:10 FRO 37000 37000 SCHAN 3 FRO change (Hz) 20.0 14.0 Echo to noise (dB/Hz) -5500 Echo center offset (Hz) 06:33 FRO 25000 25000 SCHAN 3 FRO change (Hz) 06:37 FRO 14000 14000 SCHAN 3 FRO change (Hz) 06:40 1ST of several HUGE X-BD ECHOES (>30 dB/Hz) 06:41 FRO 3000 3000 SCHAN 3 FRO change (Hz) 06:42:45 Another strong echo 06:45 FRO -7000 -7000 SCHAN 3 FRO change (Hz) 06:51 end End BSR; S-Tx, X-Tx OFF Stop 100 kHz recordings MINICAL2 06:52 1 -21.3 -21.5 -20.7 -15.3 XR ND ON 06:55 2 -19.2 -21.5 -20.8 -20.5 XR ND OFF; SR ND ON 06:58 3 -21.2 -16.9 -20.7 -20.5 SR ND OFF; XL ND ON 07:01 4 -21.2 -21.4 -18.2 -20.5 XL ND OFF; SL ND ON 07:04 5 -21.3 -21.6 -20.6 -20.8 SL ND OFF FRO 0 0 0 0 All FRO = 0 EOT 07:07 end End track DSS43 to zenith POSTCAL 07:13 1 At zenith; all to AMB AMB load physical temps: S1=20.12 S2=20.25 X1=19.69 07:16 2 -10.0 -10.0 -9.8 -9.4 XR ND ON 07:19 3 -9.8 -10.0 -9.8 -9.7 XR ND OFF; SR ND ON 07:22 4 -10.2 -9.4 -9.9 -9.8 SR ND OFF; XL ND ON 07:25 5 -10.1 -10.0 -9.7 -9.6 XL ND OFF; SL ND ON 07:28 6 -22.1 -22.3 -18.5 -22.4 All to sky 07:31 7 -22.0 -17.1 -21.3 -22.3 SL ND OFF; XL ND ON 07:34 8 -19.7 -22.3 -21.3 -22.2 XL ND OFF; SR ND ON 07:37 9 -22.2 -22.2 -21.3 -15.7 SR ND OFF; XR ND ON 07:40 10 -22.0 -22.3 -21.4 -22.2 XR ND OFF AMB load physical temps: S1=20.06 S2=20.12 X1=19.69 Weather conditions: T=8.1C H=47.2 percent sky=clear EOA 07:45 Stop 25 kHz recordings AMB = ambient load BOT = Beginning of Track CNR = Carrier to noise ratio CONSCAN = conical scan tracking CW = continuous wave (carrier only) 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 Dick Simpson Original: 2006-06-24 Added 05:50 entry to Table 3: 2006-07-12 Added AMB load phys temps before post-cal: 2006-07-17 X-RCP and S-RCP ND errors during pre-cal added: 2006-07-18