Mars Express Bistatic Radar Experiment Operations Plan and Report 01 May 2010 Summary ======= DSN Antenna: 63 Orbit: 8107 Orbit Start Time: 2010-05-01T17:32:25 HGA Pointing: Specular Start Mid Point End -------- ---------- -------- Specular Condition (ERT): 19:21 19:42 20:03 Target Latitude (deg N): -20.55 -26.52 -34.44 Longitude (deg E): 140.94 137.40 135.53 Rp (km): 3394. 3394. 3394. Incidence/Reflection Angle (deg): 40.03 45.47 52.85 Slant Range (km): 8838. 7841 6633. Slew Angle (deg): 99.39 89.06 74.29 Doppler (carrier, fd; Hz): -39844. -43359. -45278. Doppler (echo, fr; Hz): 15736. 18740. 19812. Doppler Difference (fdd; Hz): -55581. -62100. -65090. Earth-Mars Distance (m): 1.935E+11 1.935E+11 1.935E+11 Experiment Set Up ================= This experiment was conducted using the Madrid DSS 63. Danny Kahan and Gene Goltz were in the Radio Science Support Area (RSSA) at JPL. This report is largely based on notes provided by Kahan and Goltz. Performance Problems and Notes ============================== There no problems worthy of note. Data Acquisition ================ RSRs were configured as in Table 1. Table 1 ---------------------------------------------------- RSR Channel Mode ATT FGAIN Operator dB ----- ------- ---- ---- ----- ---------------------- RSR1A S-LCP 1-W auto 60 UNK RSR1B 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 2010/121 RSR1A RSR1B RSR2A RSR2B -------- ----- --------- ----- ----- ----- ----- ------------------------ FGAIN 15:44 60 60 60 65 Set FGAIN Pre-Cal 16:54 1 -11.0 -15.7 -14.5 -9.9 16:55 att auto -10.0 -9.6 -10.1 -9.9 Reset attenuators 17.5 17.5 15.5 26.5 Attenuator settings (dB) 16:56 2 -10.0 -0.3 -10.2 -0.0 16:57 3 -0.7 -0.3 -10.1 -0.1 16:58 "4,5" -0.8 -0.4 -0.6 -0.2 17:01 att auto -10.0 -10.1 -10.1 -3.2 Ambient load phys temps S1=18.94 S2=23.69 X1=15.62 28.5 28.5 27.0 31.5 Attenuator settings (dB) Local weather: T=19.2C H=45.7 percent sky=partly cloudy 17:02 rec 3 e Begin 25 kHz recording 17:02 6 -9.9 -10.2 -10.1 -3.1 17:07 7 -10.0 -10.2 -10.1 -3.0 17:12 8 -10.0 -21.8 -10.1 -12.7 17:17 9 -10.1 -21.8 -10.1 -15.0 17:22 10 -10.0 -19.8 -10.1 -15.0 Confirmed 12.5 K ND 17:27 "11,12" -10.0 -9.9 -10.2 -3.2 Ambient load phys temp: S1=18.94 S2=23.69 X1=15.62" 17:32 13 -10.1 -10.1 -10.1 -3.2 17:37 14 -10.0 -21.8 -10.1 -14.9 17:42 15 -10.1 -21.8 -9.9 -15.0 17:47 16 -9.9 -21.8 -19.5 -14.9 17:52 17 -9.9 -21.8 -21.5 -15.0 Confirmed 12.5 K ND 17:57 18 -9.8 -21.9 -21.5 -15.0 18:02 19 -19.2 -21.8 -21.4 -15.1 18:07 20 -21.0 -21.8 -21.4 -15.2 Ambient load phys temp: S1=18.69 S2=23.62 X1=15.44 18:12 21/end -21.0 -21.9 -21.3 -15.3 Stop 25 kHz recording BOT 18:35 -21.0 -21.7 -21.5 -14.3 TLM on until 18:51 18:50 rec 3 e -21.0 -21.6 -21.5 -12.7 Resume 25 kHz recording 19:00 -21.0 -21.7 -21.6 -13.0 DSS 63 switch to Mars pointing predicts 19:02 sfro 3/SX +10k +49k +10k +49k Rcvr tuning offset (Hz) sfro 4/X +45k +45k MiniCal1 19:04 1 -20.9 -21.7 -21.5 -11.3 Confirmed 12.5 K ND 19:07 2 -20.8 -21.7 -19.6 -13.0 19:10 3 -20.9 -19.7 -21.9 -13.0 19:13 4 -19.2 -21.7 -21.8 -12.9 19:16 5 -20.9 -21.7 -21.7 -12.9 19:19 end -20.9 -21.7 -21.6 -12.8 BSR 19:21 rec 4 e -20.8 -21.7 -21.6 -12.9 Begin 100 kHz recording 19:33 sfro 3/X +53k +53k Rcvr tuning offset (Hz) 19:48 sfro 3/X +57k +57k Rcvr tuning offset (Hz) end 20:03 rec 4 d -21.1 -21.6 -21.6 -12.6 end 100 kHz recording MiniCal2 20:06 1 -21.1 -21.6 -21.4 -10.8 Confirmed 12.5K ND 20:09 2 -21.1 -21.6 -19.5 -12.5 20:12 3 -21.4 -19.7 -21.3 -12.5 20:15 4 -19.6 -21.6 -21.3 -12.5 20:18 5 -21.3 -21.7 -21.3 -12.5 20:21 end -21.3 -21.7 -21.4 -13.6 20:22 sfro 3/SX 0 0 0 0 Rcvr tuning offset (Hz) Return to s/c pointing predicts EOT 20:37 stow -21.1 -21.6 -21.4 -12.6 PostCal 20:43 1 -9.8 -10.2 -9.8 -2.9 AMB load phys temps: S1=16.88 S2=21.25 X1=14.50 20:46 2 -9.8 -10.1 -9.8 -2.7 20:49 3 -9.7 -10.4 -9.7 -2.9 20:52 4 -9.7 -10.0 -9.9 -3.0 20:55 5 -9.6 -9.8 -3.0 20:58 6 -19.2 -21.0 -21.3 -14.6 21:01 7 -21.0 -19.8 -21.2 -14.5 21:04 8 -21.2 -21.8 -19.4 -14.6 21:07 9 -21.0 -21.9 -21.4 -12.2 21:10 10 -21.0 -21.9 -21.3 -14.6 AMB load phys temps: S1=16.75 S2=20.81 X1=14.94 Local weather: T=14.5C H=60.0 percent sky=partly cloudy 21:13 11/end -21.1 -21.9 -21.3 -14.6 End 25 kHz recording AMB = ambient load BOT = Beginning of Track BW = bandwidth 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 NOP = Network Operations Plan Pc = carrier power rcvr = receiver S1 = ambient load for S-RCP S2 = ambient load for S-LCP s/c = spacecraft 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 X-Band Spur: There is a spur of unknown origin that drifts with the X-Band surface echo in both polarizations. It starts about 1 kHz below the echo (19:21) and ends about 5 kHz below (20:03). It never infringes on the echo bandwidth, so careful choices of noise and echo windows keeps it from being a problem. There was an X-Band spur in data collected at DSS 63 on day 106; it started about 20 kHz above the echo and ended 6 kHz above, also not causing problems during analysis. S-LCP Amplitude Calibration: S-LCP noise power varies about 5 percent between 19:36 and 19:45 -- starting high, dropping to its final value, returning to its original value, and ending low. There is no comparable variation in S- RCP noise power. The S-LCP amplitude scaling was modified to correct for these changes by using a linear correction. The GNC file has the following entries: Gain (G) dG/dt t_start (s) t_stop (s) --------- ----------- ----------- ---------- 2761.278 0.00000000 69600.000 70560.000 2761.278 0.32181221 70560.000 70773.000 2829.824 -0.29932750 70773.000 71002.000 2761.278 0.39852326 71002.000 71174.000 2829.824 0.00000000 71174.000 72300.000 Dick Simpson Original: 2010-05-18 Added Post-Analysis Summary: 2010-05-25 Removed PDS unfriendly characters: 2011-05-17