Mars Express Bistatic Radar Experiment Operations Plan and Report 10 February 2010 Summary ======= DSN Antenna: 14 Pass: N/A Orbit: 7830 Orbit Start Time: 2010-02-10T07:18:34 HGA Pointing: Specular Start Mid Point End -------- ---------- -------- Specular Condition (ERT): 07:29 08:00 08:31 Target Latitude (deg N): -31.61 -36.63 -42.18 Longitude (deg E): 306.47 300.74 295.83 Rp (km): 3394. 3394. 3394. Incidence/Reflection Angle (deg): 45.12 50.08 55.67 Slant Range (km): 11124. 11004. 10451. Slew Angle (deg): 89.76 79.83 68.65 Doppler (carrier, fd; Hz): -31177. -32315. -31455. Doppler (echo, fr; Hz): -4485. 1497. 7149. Doppler Difference (fdd; Hz): -26691. -33812. -38603. Earth-Mars Distance (m): 1.024E+11 1.024E+11 1.024E+11 NB: The DSN is no longer routinely using pass numbers; so this entry in the summary will not be maintained in this and future reports. Experiment Set Up ================= This experiment was conducted using the Goldstone DSS 14. Danny Kahan, Gene Goltz, and Dick Simpson were in the Radio Science Support Area (RSSA) at JPL. No one was in the NOPE area. Performance Problems and Notes ============================== The S-RCP maser was red, so no S-RCP data were collected (DR N105983). Instead, the RSR normally used to collect S-RCP data was configured to capture a backup copy of S-LCP. S-RCP is expected to be available again on 2010/046. The first operator at DSS 14 (until 08:00 UTC) was rusty on radio science procedures and was using a newer version of the Network Operations Plan (NOP, Rev. M). Numbering of steps in the pre-cal was different, causing some confusion in the RSSA. Goltz downloaded the newer version of the NOP section, and the pre-cal was going more smoothly by Step 10. The pre-cal required more than two hours to complete, but there was extra time because BSR activities did not start until 50 minutes into the track. Real-time monitoring during Mini-Cal #2 indicated that the X-RCP noise diode was not turned off at 08:35 and may have remained on through the early parts of the post-cal. The three identical ambient load physical temperatures at the beginning of the post-cal are very suspicious. Goltz commented on this at the time, but the operator did not respond. 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-LCP 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-LCP X-RCP Notes / Comments 2010/041 (new NOP) RSR3A RSR3B RSR2A RSR2B -------- ----- --------- ----- ----- ----- ----- ------------------------ FGAIN 60 60 60 60 Set FGAIN PreCal 04:35 1 -6.7 -9.8 -6.0 -10.2 ADC amplitudes (dB) 04:36 att auto -10.1 -9.8 -7.9 -9.6 ADC amplitudes (dB) 04:42 2 -10.1 -2.5 -7.9 -2.2 X-Band to AMB load 04:43 3 -5.4 -2.4 -1.7 -2.1 S-LCP to AMB load 04:45 4 -5.4 -2.5 -3.7 -2.2 S-RCP to AMB (no op) 04:48 rec 3 e Begin 25 kHz recording 04:49 5 AMB load physical temps: S1= 9.69C S2=13.31C X1=11.12C Local weather: T= 3.2C H=92.6 percent Light-heavy rain 05:00 6 -9.7 -10.1 -9.8 -9.9 ADC amplitudes (dB) 26.0 14.0 27.0 22.5 Atten settings (dB) 05:02 7 -9.8 -10.1 -10.0 -9.7 X-RCP ND ON 05:07 8 -9.8 -18.3 -10.0 -17.1 X-Band to sky 05:12 9 -9.7 -18.4 -10.1 -18.4 X-RCP ND OFF 05:17 10 -9.8 -17.5 -9.9 -18.6 X-LCP ND ON Confirmed 12.5K ND 05:19 12 AMB load physical temps: S1= 9.69C S2=13.25C X1=11.00C 05:22 11 -9.8 -10.0 -9.9 -10.0 X-Band to AMB 05:27 13 -9.7 -10.1 -10.0 -9.9 X-LCP ND OFF 05:32 14 -9.8 -18.5 -10.0 -18.6 X-Band to sky 05:37 15 -9.7 -18.5 -9.9 -18.5 S-RCP ND ON (no op) 05:43 16 S-RCP to sky (no op) 05:47 17 -9.8 -18.1 -9.9 -18.0 S-RCP ND OFF (no op) Confirmed 12.5K ND 05:53 18 -9.8 -18.0 -9.9 -17.8 S-LCP ND ON 05:58 19 -14.3 -17.2 -14.1 -17.1 S-LCP to sky 06:03 20 -14.7 -17.2 -14.7 -17.1 S-LCP ND OFF AMB load physical temps: S1= 9.56C S2=13.06C X1=11.00C 06:08 21 -14.5 -17.3 -14.6 -17.1 End pre-cal Stop 25 kHz recording BOT 06:11 DSS 14 on point 06:16 -10.2 -17.3 -10.2 -17.2 No MEX signal 06:33 -10.5 -16.2 -10.5 -16.3 No MEX signal 06:39 -11.3 -16.3 -11.4 -16.5 ADC amplitude (dB) -1143 -2191 -2191 Carrier offset (Hz) 28.0 40.5 69.0 Carrier-to-noise (dB/Hz) 06:40 28.0 35.5 62.0 Carrier-to-noise (dB/Hz) 06:47 MEX MOC wants telemetry; says project expects it 06:49 MEX MOC backs off, withdraws request 06:50 -11.8 -16.2 -12.3 -14.6 ADC amplitude (dB) 29.3 35.2 29.2 62.2 Carrier-to-noise (dB/Hz) 06:50 rec 3 e Resume 25 kHz recording 06:54 29.6 41.3 29.6 69.1 CNR (dB/Hz); TLM OFF Clipping on XR SCHAN 2, No clipping on SCHAN 3 07:05 29.5 68.8 CNR (dB/Hz) Begin SLEW #1 07:08 10.5 39.5 CNR (dB/Hz) 07:10 DSS 14 switch to planetary coordinates 07:11 sfro 3/SX +5K +29.6K +5K +29.6 K Rcvr tuning offset (Hz) MiniCal1 07:12 1 -13.8 -16.5 -13.6 -14.5 XR ND ON (ADC amp, dB) 07:14 -6340 SL carrier offset (Hz) 07:15 2 -15.1 -16.5 -15.8 -15.2 XR ND OFF, SR ND ON 07:18 3 SR ND OFF, XL ND ON 07:21 4 -15.1 -16.5 -16.0 -14.7 XL ND OFF, SL ND ON 07:26 5 -12.6 -16.6 -13.8 -15.3 SL ND OFF BSR 07:29 20.0 32.0 25.0 Echo to noise (dB/Hz) rec 4 e Begin 100 kHz recording End SLEW #1 07:33 1160 -4800 Echo offset (Hz) -6400 Carrier offset (Hz) 07:57 -191 2501 -31 Echo offset (Hz) 33.1 23.3 27.9 Echo peak (dB/Hz) -6502 Carrier offset (Hz) 19.8 Carrier peak (dB/Hz) 08:13 3111 3230 2965 Echo offset (Hz) 30.9 20.3 26.3 Echo peak (dB/Hz) -6525 Carrier offset (Hz) 20.3 Carrier peak (dB/Hz) 08:27 4960 3970 4913 Echo offset (Hz) 31.6 21.4 27.8 Echo peak (dB/Hz) 08:30 -17.1 -16.4 -16.7 -16.5 ADC amplitude (dB) 08:31 rec 4 d End 100 kHz recording Begin SLEW #2 (to Earth) MiniCal2 08:32 1 -16.3 -16.5 -15.9 -14.4 XR ND ON 08:35 2 -16.2 -16.4 -15.6 -14.8 XR ND OFF, SR ND ON 08:38 3 -14.0 -15.7 -14.3 -14.7 SR ND OFF, XL ND ON 08:41 22.0 CNR (dB/Hz) -6554 Carrier offset (Hz) 08:41 4 -16.9 -16.5 -17.0 -14.6 XL ND OFF, SL ND ON 08:44 5 -17.1 -16.6 -16.9 -14.6 SL ND OFF 08:47 end DSS 14 switch back to spacecraft pointing 08:48 0 0 0 0 Rcvr tuning offset (Hz) 26.2 54.2 CNR (dB/Hz) -1560 -3719 Carrier offset (Hz) 08:50 End SLEW #2 08:51 25.8 70.4 CNR (dB/Hz); clipping on X-RCP SCHAN 3 EOT 09:07 Early end of track 09:12 Zenith -15.0 -16.3 -14.9 -16.2 ADC amplitudes (dB) PostCal 09:26 1 -9.7 -10.1 -9.9 -10.0 All to AMB 09:27 AMB load physical temps: S1=10.75C S2=10.75C X1=10.75C These are suspicious ... 09:30 2 -9.8 -10.1 -10.1 -9.9 XR ND ON 09:33 3 -9.8 -10.1 -10.0 -9.9 XR ND OFF, SR ND ON 09:36 4 -9.7 -10.0 -9.8 -9.9 SR ND OFF, XL ND ON 09:39 5 -9.8 -10.0 -9.9 -9.9 XL ND OFF, SL ND ON 09:42 6 -14.3 -16.5 -14.3 -16.4 All to sky 09:45 7 -14.4 -15.7 -14.6 -16.5 SL ND OFF, XL ND ON 09:48 8 -14.5 -16.5 -14.5 -16.4 XL ND OFF, SR ND ON 09:51 9 -14.4 -16.6 -14.5 -15.7 SR ND OFF, XR ND ON 09:54 10 -14.3 -16.5 -14.9 -16.5 XR ND OFF AMB load physical temps: S1= 9.31C S2=12.56C X1=10.75C Local weather: T= 3.7C H=89.1 percent W=5.6 mph Sky=partly cloudy EOA 10:00 end 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 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 Good echoes throughout. Some echoes may not be beam-limited. For example at 07:48:54 the S-Band half-power width is less than 363 Hz (possibly as little as 150 Hz). The X- Band width is 448 Hz. The X-Band width is less than half the beam-limited width for 0.1 rms slopes. The inferred X-Band rms slope is 2.43 deg (35S, 57W). X-Band system temperatures were 40-70K, with an unexplained rise while the S- Band pre-cal was being completed that persisted through the remainder of the pass. There may be a small contribution from Mars to X-Band Tsys. S-LCP seemed normal (25-28K). There was strong correlation between X-RCP and X-LCP noise whenever the LNAs were looking out the horn (during tracking and also during the pre-cal). The correlation was not present when the LNAs were looking at the ambient load. Dick Simpson Original: 2010-02-10 Minor edits; added Post-Analysis Summary: 2010-02-17 Minor edits for odd characters: 2011-05-10