Mars Express Bistatic Radar Experiment Operations Plan and Report 12 July 2009 Summary ======= DSN Antenna: 14 Pass: 2234 Orbit: 7090 Orbit Start Time: 2009-06-12T16:35:15 HGA Pointing: Specular Start Center End -------- ---------- -------- Specular Condition (ERT): 19:08 19:45 20:15 Target Latitude (deg N): 47.40 49.25 -5.83 Longitude (deg E): 268.16 304.53 338.45 Rp (km): 3394. 3394. 3394. Incidence/Reflection Angle (deg): 63.19 60.02 55.11 Slant Range (km): 6980. 3397. 542. Slew Angle (deg): 53.62 59.96 69.78 Doppler (carrier, fd; Hz): 28580. 35995. 5520. Doppler (echo, fr; Hz): 39040. 55823. 12354. Doppler Difference (fdd; Hz): -10461. -19828. -6834. Earth-Mars Distance (m): 2.763E+11 2.763E+11 2.763E+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 ============================== Configuration of RSRs with respective feeds was different compared to the usual configuration (see Table 3); but all signals were available and recorded. A strong interfering signal of unknown origin drifted through the S-RCP and S-LCP passbands between 19:09:40 and 19:11:00. Noise and echo power estimates during this time should be considered invalid. Data Acquisition ================ RSRs were configured as in Table 1. Table 1 ---------------------------------------------------- RSR Channel Mode ATT FGAIN Operator dB ----- ------- ---- ---- ----- ---------------------- RSR2A S-LCP 1-W auto 60 UNK RSR3B X-LCP 1-W auto 60 UNK RSR3A 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 2009/193 RSR2A RSR3B RSR3A RSR2B -------- ----- --------- ----- ----- ----- ----- ------------------------ fgain 14:14 60 60 60 60 GAIN = 60 dB Pre-Cal 14:36 1 -0.8 -9.4 -11.7 -9.8 14:40 att auto -9.9 -9.8 -10.2 -9.8 ADC amplitude (dB) 19.5 12.0 7.0 11.0 Attenuator settings (dB) 14:42 2 -10.5 -0.1 -10.2 +0.0 14:50 3 -3.1 -0.1 -10.0 +-.1 SR/SL reversed 14:55 4 -3.0 -0.0 -0.7 +0.1 14:57 att auto -9.7 -10.0 -10.2 -10.0 AMB loads phys temps: S1=16.38 S2=21.81 X1=13.62 26.5 24.4 18.0 23.5 Attenuator settings (dB) Local weather: T=26.6C H=21.5 percent sky=clear 15:00 rec 3 e -9.8 -10.1 -9.9 -9.7 Begin 25 kHz recording 15:00 5 -9.6 -10.2 -9.9 -9.6 15:05 6 -9.8 -10.1 -10.0 -9.5 15:10 7 -9.6 -22.1 -9.9 -19.9 15:15 8 -9.7 -22.1 -10.0 -22.3 15:20 9 -9.7 -19.9 -9.9 -22.2 Confirm 12.5K ND 15:25 10 -9.7 -9.9 -9.9 -9.8 AMB load phys temps: S1=16.56 S2=21.88 X1=13.81 15:30 11 -9.8 -10.1 -10.1 -9.8 15:35 12 -9.7 -22.2 -10.1 -22.3 15:40 13 -9.7 -22.1 -9.8 -22.3 15:45 14 -9.7 -22.2 -19.2 -22.3 15:50 15 -9.7 -22.3 -21.0 -22.3 Confirm 12.5K ND 15:55 16 -9.5 -22.3 -21.0 -22.2 16:00 17 -14.2 -22.3 -21.1 -22.4 16:05 18 -17.4 -22.3 -21.1 -22.4 AMB load phys temps: S1=16.88 S2=22.19 X1=14.12 16:10 end +0.2 -22.4 -21.2 -21.4 Stop 25 kHz recording BOT 16:30 -13.9 -22.4 -21.2 -21.4 17:41 X-band -12.3 -22.3 -21.3 -21.4 Collecting TLM to 18:43 18:28 S-band -18.3 -22.0 -21.4 -22.0 18:43 rec 3 e -15.4 -22.2 -21.4 -22.1 Resume 25 kHz recording 18:50 -18.3 -22.2 -21.4 -22.0 Switch DSS 14 to Mars pointing predicts 18:53 sfro +11k +10k +11k +10k Rcvr tuning offset (Hz) MiniCal1 18:53 1 -18.3 -22.1 -21.5 -19.9 Confirm 12.5K ND 18:56 2 -17.3 -22.0 -19.8 -22.2 19:00 3 -18.9 -20.0 -21.5 -22.3 19:02:30 4 -17.7 -22.1 -21.6 -22.4 19:05 5 -19.2 -22.2 -21.5 -21.3 19:08 end -18.8 -22.1 -21.5 -21.4 BSR 19:08 sfro -2k +7k -2k +7k Rcvr tuning offset (Hz) Begin 100 kHz recording 19:38 sfro +14k +14k Rcvr tuning offset (Hz) 20:05 -17.7 -21.9 -21.4 -21.1 Cratered terrain 20:10 sfro +8k +8k Rcvr tuning offset (Hz) 20:13 sfro +2k +2k Rcvr tuning offset (Hz) end BSR 20:16 sfro +11k +10k +11k +10k End 100 kHx recording MiniCal2 20:16 1 -18.1 -21.9 -21.4 -19.9 Confirm 12.5K ND 20:19 2 -19.3 -21.8 -19.7 -22.0 20:22 3 -18.7 -19.8 -21.3 -21.9 20:25 4 -17.9 -21.7 -21.4 -21.0 20:28 5 -18.8 -21.7 -21.4 -21.9 20:31 end -18.7 -21.6 -21.3 -21.8 20:32 -18.8 -21.7 -21.3 -21.8 Switch DSS 14 to S/C pointing predicts EOT 20:47 EOT -19.6 -21.6 -21.2 -21.6 PostCal 1 -10.4 -10.2 -10.8 -10.0 AMB load phys temps: S1=21.94 S2=30.62 X1=19.44 2 -10.2 -10.2 -10.7 -9.8 3 -10.1 -10.1 -10.6 -10.0 4 -10.2 -10.0 -10.7 -10.0 5 -10.0 -10.1 -10.9 -10.0 6 -15.5 -22.4 -21.6 -22.7 7 -16.7 -20.0 -21.7 -22.6 8 -16.1 -22.3 -20.0 -22.5 9 -16.4 -22.3 -21.7 -20.3 10 -15.2 -22.3 -21.6 -22.7 AMB load phys temps: S1=21.88 S2=30.50 X1=19.31 Local weather: T=36.3C H=8.3 percent sky=clear EOA -16.5 -22.4 -21.7 -22.7 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. Spectra are 10-second averages (N=244). No carrier suppression was used. Interval Times Spectra Carrier Split Notes on Echo, FRO, etc. Bin Echo -------- ----------------- ------- ------- ----- ------------------------ A 19:08:00-19:24:40 001-100 88 Drifts slowly up B 19:24:40-19:38:00 101-180 88 Drifts slowly up BC 19:38:00-19:38:10 181 181 Split echo C 19:38:10-19:49:40 182-250 Drifts slowly up D 19:49:40-20:06:20 251-350 Reverses, starts down E 20:06:20-20:16:00 351-408 373 FRO at 20:10 294 391 FRO at 20:13 The MOVIE program was run for the spectra ranges shown above with the first spectrum in each range also providing the last MOVIE output in the previous run. The overlapping echo power values agreed to 1 percent. For S-Band, the table below summarizes the processing. Spectra are 60-s averages (N=1464). No carrier suppression was used. Interval Times Spectra Carrier Split Notes on Echo, FRO, etc. Bin Echo -------- ----------- ------- ------- ----- -------------------------- A 19:08-19:48 001-040 535 Drifts slowly up B 19:48-20:07 041-059 535 Turns around, drifts down C 20:07-20:16 060-068 535 Drifts down more quickly Dick Simpson Original: 2009-09-23 Added Post Analysis Summary: 2009-10-29