Mars Express Bistatic Radar Experiment Operations Plan and Report 3 July 2009 Summary ======= DSN Antenna: 14 Pass: 2225 Orbit: 7058 Orbit Start Time: 2009-07-03T11:57:16 HGA Pointing: Specular Start Center End -------- ---------- -------- Specular Condition (ERT): 14:58 15:32 16:05 Target Latitude (deg N): 49.10 6.34 -70.03 Longitude (deg E): 278.91 321.47 240.01 Rp (km): 3394. 3394. 3394. Incidence/Reflection Angle (deg): 61.42 60.14 58.86 Slant Range (km): 4425. 861. 2577. Slew Angle (deg): 57.15 59.73 62.29 Doppler (carrier, fd; Hz): 29226. 17405. -27093. Doppler (echo, fr; Hz): 48990. 33606. -53256. Doppler Difference (fdd; Hz): -19763. -16201. 26164. Earth-Mars Distance (m): 2.818E+11 2.818E+11 2.818E+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 ============================== DSS 14 personnel were not familiar with BSR procedures. There was some confusion about step 5 in the pre-cal; the X-RCP receiver was not left looking at the ambient load for the normal time. The first mini-cal was not completed; there are no X-LCP or S-LCP calibration measurements. The surface observations themselves and all of the post-experiment calibrations appear to be nominal, however. 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 2009/184 RSR1A RSR1B RSR2A RSR2B -------- ----- --------- ----- ----- ----- ----- ------------------------ Pre-Cal 12:20 1 -8.9 -9.7 -11.4 -10.0 12:21 att auto -10.1 -10.2 -9.9 -9.9 14.0 12.5 4.5 11.0 Attenuator settings (dB) 12:23 2 -10.0 -0.2 -9.8 -0.0 12:28 3 -3.0 -0.3 -9.9 +0.0 12:30 4 -3.1 -0.3 -0.6 -0.0 12:31 att auto -10.1 -10.0 -9.9 -9.9 21.5 24.5 15.5 23.5 Attenuator settings (dB) AMB load phys temps: S1=15.81 S2=20.75 X1=13.31" Weather: T=22.2C H=29.1 percent sky=clear 12:33 rec 3 e Begin 25 kHz recording 12:34 5 -10.1 -10.0 -9.8 -9.7 12:40 6 -10.1 -10.0 -9.9 -9.6 12:45 7 -10.2 -22.1 -9.9 -20.1 12:50 8 -10.2 -22.1 -10.0 -22.5 12:55 9 -10.1 -19.8 -9.9 -22.4 Confirm 12.5K ND 13:05 10 -10.1 -9.7 -9.9 -9.8 AMB load phys temps: S1=15.56 S2=20.50 X1=13.25 13:10 11 -10.1 -10.1 -10.0 -9.9 13:15 12 -10.1 -22.1 -9.9 -22.4 13:20 13 -10.1 -22.2 -9.7 -22.4 13:25 14 -10.0 -22.1 -21.2 -22.4 13:30 15 -10.1 -22.1 -21.1 -22.5 Confirm 12.5K ND 13:35 16 -9.9 -22.1 -21.1 -22.5 13:40 17 -14.9 -22.1 -21.1 -22.4 13:45 18 -16.6 -22.1 -21.2 -22.5 AMB load phys temps: S1=15.44 S2=20.31 X1=13.06 13:50 end -17.2 -22.1 -21.2 -22.5 Stop 25 kHz recording BOT 14:00 Collecting telemetry until 14:30 14:30 rec 3 e -14.5 -22.0 -21.0 -20.8 Resume 25 kHz recording 14:40 sfro 3/SX +11k +10k +11k +10k MiniCal1 14:41 1 -15.9 -21.9 -21.1 -19.1 Confirm 12.5K ND 14:44 2 problems - step not executed 14:47 3 problems - step not executed 14:50 4 problems - step not executed 14:53 5 problems - step not executed 14:56 end confirm configurations and continue BSR 14:58 sfro 3/SX -2k +14k -2k +14k Begin 100 kHz recording 15:26 Pass VL-1 site 15:31 sfro 3/X +7k +7k 15:35 sfro 3/X 0 0 15:38 sfro 3/X -7k -7k 15:40 sfro 3/S -9k -9l 15:41 sfro 3/X -14k -14k 15:44 sfro 3/X -21k -21k 15:47 sfro 3/X -28k -28k 15:54 sfro 3/X -35k -35k 16:05 sfro 3/SX +11k +10k +11k +10k End 100 kHz recording MiniCal2 16:05 1 -14.1 -22.0 -21.2 -20.1 Confirm 12.5K ND 16:08 2 -13.1 -22.1 -19.3 -22.3 16:11 3 -14.2 -19.9 -21.1 -22.4 16:14 4 -14.5 -22.1 -21.2 -22.4 16:17 5 -15.0 -22.1 -21.1 -21.1 16:20 end -14.8 -22.1 -21.1 -21.1 16:20 sfro 3/SX 0 0 0 0 16:24 Switch to spacecraft pointing predicts 16:30 rec 3 d -13.4 -22.1 -21.1 -21,1 Stop 25 kHz recording 16:30 Collecting telemetry until 17:10 EOT 17:10 -14.7 -22.3 -21.3 -22.6 Resume 25 kHz recording Post-Cal 1 -10.2 -10.1 -10.0 -9.9 AMB load phys temps: S1=17.69 S2=23.25 X1=14.81 2 -10.1 -10.1 -10.0 -9.8 3 -10.2 -10.1 -9.9 -10.1 4 -10.1 -9.9 -10.1 -10.1 5 -9.9 -10.0 -10.3 -10.1 6 -16.0 -22.2 -21.2 -22.6 7 -16.3 -19.9 -21.3 -22.5 8 -17.0 -22.3 -19.4 -22.5 9 -16.5 -22.1 -21.3 -20.1 10 -17.5 -22.3 -21.2 -22.6 AMB load phys temps: S1=18.12 S2=23.38 X1=15.12 Weather: T=33.0C H=12.5 percent sky=clear EOA -17.5 -22.1 -21.2 -22.6 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 first table below lists the time intervals over which X-Band data were processed by the MOVIE program. Intervals were chosen primarily on the basis of times and magnitudes of receiver frequency offsets (FRO). 'Split echo' is an interval in which the FRO caused the echo to appear at two distinct frequencies. The echo power estimate is usually correct (or nearly so) if the echo integration bandwidth was chosen large enough. That appears to be the case for the split echoes noted here. 'Carrier Suppression' was used when the residual carrier propagating directly from the spacecraft fell within the bandwidth over which the echo power was calculated. Carrier signals in these data are small relative to the echo powers; the correction process has been validated previously. For these data, carrier suppression is a minor correction. 'MOVIE Run' lists the spectra over which the MOVIE program was run and from which its output was saved. For previous experiments, all spectra were calculated with all processing parameter selections; for 2009 that would have led to a large number of useless results, so only the parameter choices for the intervals over which they were valid were calculated and saved. The second table gives the S-Band processing intervals (for 60 s average spectra) X-Band Spectra Times Split Carrier MOVIE Interval Echo Suppression Run -------- ------- ----------------- ----- ----------- ------- A 001-198 14:58:00-15:31:00 001-199 B 199-240 15:31:00-15:38:00 199 199-241 223 C 241-277 15:38:00-15:44:10 241 Y 241-277 259 Y 277 Y D 278-337 15:44:10-15:54:10 295 277-337 337 E 338-402 15:54:10-16:05:00 337-402 S-Band Spectra Times Split Carrier MOVIE Interval Echo Suppression Run -------- ------- ----------------- ----- ----------- ------- A 001-032 14:58:00-15:30:00 001-032 B 033-042 15:30:00-15:40:00 Y 030-043 C 043-053 15:40:00-15:51:00 Y 043-053 D 054-067 15:51:00-16:05:10 053-067 Dick Simpson Original: 2009-08-10 Added Post-Analysis Summary: 2009-08-17 Various edits: 2009-09-23