PDS_VERSION = PDS3 RECORD_TYPE = STREAM OBJECT = TEXT PUBLICATION_DATE = 1997-07-19 NOTE = "MGS RST Instrument Health Report HEA7200A.TXT" END_OBJECT = TEXT END Engineering Data ================ Engineering Data Statistical Summary from CSV2STAT: First SCET: 1997-07-18T00:00:00.441 Last SCET: 1997-07-18T23:59:59.935 CHANNL CHANNEL TITLE DN-LO DN-HI EU-LO EU-HI EU-AVG/STDEV RECDS ------ ------------- ----- ----- --------- --------- ---------/-------- ----- L-0034 MOT1_RANGING 0 0 18020 L-0036 MOT1_TLM_MOD 0 0 18020 L-0037 MOT1_USO_ENA 0 0 18020 L-0044 MOT2_RANGING 1 1 18020 L-0046 MOT2_TLM_MOD 1 1 18020 L-0047 MOT2_USO_ENA 1 1 18020 L-0053 RF_SW_OSC 1 1 18020 L-0060 TWTA1_FILMNT 0 0 18020 L-0061 TWTA1_HV 0 1 18790 L-0070 TWTA2_FILMNT 1 1 18790 L-0071 TWTA2_HV 0 0 18020 L-0080 USO_PWR 0 0 18020 L-0090 KaBLE_STAT 1 1 18020 L-0091 KaBLE_ENABLE 0 1 18790 L-0111 MOT1_RCV_AGC 201 255 -1.53E+02 -1.37E+02 -1.45E+02/4.23E-02 9834 L-0121 MOT2_RCV_AGC 152 255 -1.53E+02 -1.24E+02 -1.32E+02/6.70E-02 9834 L-0131 TWTA1_HLX_I 0 1 -3.84E-02 -1.85E-02 -3.83E-02/1.10E-05 9834 L-0132 TWTA1_ANOD_V 0 2 -1.00E+03 -1.00E+03 -1.00E+03/3.19E-03 8392 L-0141 TWTA2_HLX_I 39 43 7.25E-01 8.05E-01 7.64E-01/1.38E-04 9834 L-0142 TWTA2_ANOD_V 60 64 -8.68E+02 -8.60E+02 -8.63E+02/1.46E-02 8392 L-0200 USO_REG_V 203 205 4.06E+00 4.10E+00 4.08E+00/9.02E-05 8393 L-0201 USO_OVEN_V 123 126 2.46E+00 2.52E+00 2.50E+00/8.08E-05 8393 T-0302 EPC1_T 120 129 2.37E+01 2.77E+01 2.61E+01/1.85E-02 2251 T-0303 EPC2_T 107 117 2.90E+01 3.33E+01 3.14E+01/1.86E-02 2251 T-0310 RF_ISOLTR1_T 179 188 2.53E+01 2.86E+01 2.74E+01/6.77E-03 9834 T-0311 RF_ISOLTR2_T 170 179 2.86E+01 3.17E+01 3.04E+01/6.50E-03 9834 T-0312 TWT1_T 177 187 2.57E+01 2.93E+01 2.78E+01/1.51E-02 2251 T-0313 TWT2_T 163 173 3.07E+01 3.42E+01 3.27E+01/1.56E-02 2251 T-0315 USO_T 172 175 1.15E+01 1.24E+01 1.19E+01/3.65E-03 2251 T-0316 KA_AMP_T 149 159 3.56E+01 3.93E+01 3.79E+01/1.21E-02 4297 L-0200, L-0201, and T-0315 are nominal. Open Loop Data ============== Data Collection --------------- We qeuried for an additional 1695 ODS records prior to USO Test #12. These were collected by the DSP but had not been listed in earlier communications from the RSST. We were interested in these data because the new DSP software uses a different buffering scheme and we have been told that POCA times and values were unreliable for the first 30 seconds after DSP start-up. The DSP began operation at 00:05:00, so we should be able to look at these early records. YYYY/DDD DSS QUERY SAMP BW DSP BIT TRK REC RECS RECS SNR START STOP RATE MODE RESN MODE LEN MSSG -------- --- -------- -------- ---- ---- ---- ---- ---- ---- ----- ---- ----- 1997/198 25 00:05:00 00:10:39 5000 2500 2 12 1-W 1666 1694 1 N/A Anomalies --------- The single missing record out of 1695 requested is ominous. But there was apparently no retransmission of these few records. This suggests that a near- real-time delivery of ODS data followed by a retransmission -- the case for the original 36000 records -- is an effective way to improve the reliability of data delivery. Analyses -------- Joe Twicken has completed his analysis of the USO Test #12 data. His report is reproduced here: I have processed the ODS data from 97/198. This ODS was recorded at DSS 25. The data were acquired as part of USO Test #12. Telemetry was off during the test, and the SNR was approximately 55 dB/Hz. This was the second USO Test since MGS was brought back from safe mode. All files for processing this ODS were recorded in the MgsDB database. The ODS was acquired at DSS 25 from 00:10:39 to 02:10:39 at 5000 samples per second in mode 2 (1250 12-bit samples/second for each of 4 A/D's). Telemetry was off during this time period. The ODS was obtained following a retransmission and there were not any missing records. This was the first open-loop data that I have analyzed following the recent installation of new DSP-R software. Among other things, this software is supposed to fix the POCA time tag, readback frequency and frequency rate errors which we have seen in all open-loop recordings since the RSSD was installed. I am happy to report that there were no POCA errors in this ODS of the type addressed by the new DSP-R software. There was one single POCA discrepancy, however. At time 00:14:22, there was a 10 microHertz difference between the actual readback frequency and the frequency that would have been expected given the prior readback frequency and ramp rate. This was observed just prior to the first ramp rate change in the POCA, and has been observed prior to ramp rate changes in a number of open-loop recordings for MGS and GLL. Fortunately, the problem was fixed automatically with the "salvagePoca" program. I used the spk_c_970525-970903 SP-kernel file to steer the data. This file was created on 97/197. The power spectra of the USO Test #12 did not exhibit any 650 Hz spurs above and below the carrier. It is now apparent that the spurs are only evident when telemetry is on. The spectra did show spurs at 180 Hz above and below the carrier at a level of 43 dB below that of the carrier. These spurs were also present in the RS ORT #2 open-loop data recorded at the same station earlier in the week. They were not present in the RS ORT #1 data recorded at DSS 65 on 97/189. They were present in the USO Test #11 data recorded on 97/162 at DSS 25. Amplitude fluctuations were very small, on the order of 0.2 dB peak to peak. There was no obvious period in the fluctuations. I estimated the USO frequency to be 8423152957.05 Hz. The best linear fit to the USO frequency estimates since MGS was brought back from safe mode has a slope of 0.179 Hz/day. The standard deviation of the residual errors to this fit (for recordings since 97/162) is approximately 0.01 Hz. I have estimated the USO Allan deviation at a number of integration times from this ODS. The SNR during the test was approximately 55 dB/Hz. I did not compensate for the spacecraft spin cycle. The measurements are nearly identical to those of USO Test #11. They are somewhat worse than the measurements made from the recordings of the prior USO tests. On one hand, it could be that the USO stability has deteriorated somewhat as a result of the safe mode episode. On the other hand, it could be that the stability is reflecting poorer performance of the DSS 25 BMG system relative to the other stations/systems. USO Tests 11 and 12 are the only recordings I have analyzed from DSS 25 since the MGS HGA was deployed. The Allan deviation for this test follows: t (sec) AD ------ ---------- 0.4096 1.0104e-12 1.6384 3.8017e-13 3.2768 2.6575e-13 6.5536 2.0260e-13 26.2144 1.4453e-13 Closed Loop Data ================ Data Collection --------------- No new data