PDS_VERSION = PDS3 RECORD_TYPE = STREAM OBJECT = TEXT PUBLICATION_DATE = 1998-03-24 NOTE = "MGS RST Instrument Health Report HEA8083B.TXT" END_OBJECT = TEXT END Miscellaneous ============= After 92 MGS occultations we have compiled the following summary list of data quality. This is an update of the report covering 55 occultations (HEA8064B.TXT) issued on 1998-03-05. Grouped into four broad categories of quality, the data show some improvement since the last report although outright failures remain about the same. First Report Current Report (HEA8064B.TXT) (HEA8083B.TXT) 1998-03-05 1998-03-24 55 occultations 92 occultations ---------------- ---------------- Good 27 (49%) 51 (55%) Degraded 16 (29%) 24 (26%) Likely unusable 8 (15%) 10 (11%) No data 4 (07%) 7 (08%) Categories (1)-(2) below resulted in no useful data; categories (3)-(4) resulted in poor data which probably will not allow inversion to atmospheric profiles. Categories (5)-(6) yield profiles, but of degraded quality. Note that every SPC 60 occultation which did not fall in a more serious category lies here. Category (7) problems do not impact current processing, but may limit ability to obtain high- resolution profiles later. Category (8) problems are worrisome; but, in this specific case, there appears to have been little or no impact on the quality of the atmospheric profiles eventually derived. Category (9) are occultations with (at most) minor problems. Data with problems (such as erroneous POCA readings) which we now correct automatically would appear in (9) without even a flag. Note that such a list may oversimplify the picture. Occultation 50 would not have even been attempted had the DSP not been cleared of 'red' status just minutes before the event; the filter selection was the reason the data are not usable, but it was the DSP status that was the underlying cause of the failure. On the other hand, data from Occultation 48 would have been degraded by SNR even if the POCA had worked normally. With regard to Category (5), SPC 60 data were typically 5 dB lower than data from other complexes in carrier-to-noise level. Recently DSS 54 has been doing better, although it is still not "normal." The last observations with DSS 65 were 5 dB low, however. Start Date/Time DSS Comments ------------------- -- ---------------------------------------- (1) DSP red or other ground hardware problems: ------------------- -- ---------------------------------------- 1998-02-03 65 Occ 12: DSP red; no data 1998-03-12T16:17:00 54 Occ 69: DSP red; no data 1998-03-15T09:57:00 65 Occ 74: DSP red; no data (2) Operations Errors: ------------------- -- ---------------------------------------- 1998-01-30 54 Occ 07: DSP reboot error; no data 1998-02-11 45 Occ 22: DSP predict load error 1998-02-13T05:46:41 45 Occ 25: DSP setup error; no data 1998-03-01T15:57:09 65 Occ 50: Wrong filter; no good data (3) POCA Synchronization or Frequency Stability: ------------------- -- ---------------------------------------- 1998-01-24T19:15:36 15 Occ 01: DSP buffer failure; no good data 1998-02-04T07:38:40 45 Occ 13: Samples/POCA out of sync 1998-02-22T17:49:10 15 Occ 39: Samples/POCA out of sync 1998-02-24T00:49:06 25 Occ 41: poor frequency stability 1998-02-25T22:32:42 25 Occ 44: Poor frequency stability 1998-02-28T10:22:20 65 Occ 48: POCA async; SNR 5 dB low 1998-03-05T20:06:11 25 Occ 57: Hi freq resids 1998-03-17T00:44:41 15 Occ 77: POCA/samples out of sync 1998-03-19T03:18:40 34 Occ 81: Large freq fluctuations 1998-03-18T14:47:14 65 Occ 80: SNR 4 dB low; sample/POCA sync (4) Bad Spurs: ------------------- -- ---------------------------------------- 1998-02-08T20:58:15 15 Occ 19: Spurs at +/-N*30 Hz from carrier (5) Degraded SNR: ------------------- -- ---------------------------------------- 1998-01-25T15:33:17 65 Occ 02: Grazing; SNR variable, 6 dB low 1998-02-06T14:48:50 65 Occ 16: SNR 7 dB low; samples lost sync 1998-02-09T14:19:21 65 Occ 20: Reduced, variable amplitude 1998-02-12T12:40:17 65 Occ 24: Good; SNR 6 DB low 1998-02-14T15:37:05 65 Occ 27: 0.5 dB level glitch; SNR -6 dB 1998-02-17T09:55:10 65 Occ 31: Good; SNR 6 dB low 1998-02-19T10:37:00 54 Occ 34: Good: SNR 4 dB low 1998-02-21T10:31:40 54 Occ 37: Good; SNR 3 dB low 1998-02-23T09:22:11 54 Occ 40: Good; SNR 3 dB low 1998-02-24T16:09:47 54 Occ 42: SNR a little low 1998-02-26T13:41:15 65 Occ 45: SNR 5 dB low 1998-03-03T11:17:15 54 Occ 53: SNR 3 dB low 1998-03-04T15:55:45 65 Occ 55: SNR 4 dB low 1998-03-06T10:03:25 65 Occ 58: SNR 4 dB low 1998-03-07T13:50:34 65 Occ 60: SNR 5 dB low 1998-03-08T17:25:17 65 Occ 62: SNR 5 dB low 1998-03-10T10:24:10 54 Occ 65: SNR 4 dB low 1998-03-14T07:50:15 34 Occ 72: SNR low, SNT hi; +/-0.4 dB ampl 1998-03-09T07:10:00 34 Occ 63: many dup rcds; SNR low; ... 1998-03-20T16:21:24 65 Occ 84: SNR 5 dB low (6) Poor Weather: ------------------- -- ---------------------------------------- 1998-01-26T11:47:40 65 Occ 03: 1st surf occ; snow, SNR -17 dB (7) Spurs: ------------------- -- ---------------------------------------- 1998-02-18T18:30:35 25 Occ 33: Spurs at +/-200 Hz from carrier 1998-02-20T18:38:40 25 Occ 36: Spurs at +/-200 Hz from carrier (8) Bullets Dodged: ------------------- -- ---------------------------------------- 1998-03-08T03:39:38 45 Occ 61: many dup rcds 1998-03-10T23:53:16 15 Occ 66: 7 recs missing after occn 1998-03-18T02:11:37 34 Occ 79: CONSCAN on at first, but occ OK (9) Good Data: ------------------- -- ---------------------------------------- 1998-01-27T07:45:38 45 Occ 04: Good data; multipath near occn 1998-01-28T02:36:00 43 Occ 05: Good; delivered 8 days later 1998-01-28T23:18:18 15 Occ 06: Good data, delivered quickly 1998-01-31T09:23:00 45 Occ 08: Carrier amplitude +/-0.5 dB 1998-02-01T04:25:48 45 Occ 09: Good 1998-02-01T23:24:48 15 Occ 10: Good 1998-02-02T18:15:44 15 Occ 11: Good 1998-02-05T02:10:15 45 Occ 14: Good 1998-02-05T20:31:00 15 Occ 15: Good 1998-02-07T08:56:58 45 Occ 17: Good; SNR 2 dB below expected 1998-02-08T03:01:58 45 Occ 18: Good 1998-02-10T08:30:10 45 Occ 21: +/-0.3 dB amplitude variations 1998-02-11T19:26:19 15 Occ 23: Good; hand-edited 1 POCA error 1998-02-13T22:44:30 15 Occ 26: Good 1998-02-15T08:22:34 45 Occ 28: Good 1998-02-16T00:58:50 15 Occ 29: Good; +/-0.5 dB amp var 1998-02-16T17:29:26 15 Occ 30: Good; +/-0.3 dB amp var 1998-02-18T02:15:50 45 Occ 32: Good 1998-02-20T02:39:50 45 Occ 35: Good 1998-02-22T02:13:05 45 Occ 38: Good 1998-02-25T07:24:33 45 Occ 43: 1998-02-27T04:41:15 34 Occ 46: Good. 1998-02-27T19:31:27 15 Occ 47: Ampl mod before occn 1998-03-01T01:06:15 15 Occ 49: Good 1998-03-02T06:22:35 45 Occ 51: Good 1998-03-02T20:51:50 15 Occ 52: correctable POCA error 1998-03-04T01:40:15 15 Occ 54: Good 1998-03-05T06:07:10 34 Occ 56: Good 1998-03-06T23:59:21 15 Occ 59: +/-0.5 db amp varn pre occ 1998-03-09T20:47:33 15 Occ 64: Good 1998-03-11T13:21:00 54 Occ 67: Good 1998-03-12T02:46:15 34 Occ 68: Good 1998-03-13T05:24:44 34 Occ 70: Good 1998-03-13T18:38:46 15 Occ 71: Good 1998-03-14T20:56:29 15 Occ 73: Good 1998-03-15T22:59:08 15 Occ 75: Good 1998-03-16T11:54:45 54 Occ 76: SNR 2 dB low 1998-03-17T13:31:18 54 Occ 78: SNR 2 dB low 1998-03-19T15:43:44 54 Occ 82: Good 1998-03-20T04:07:00 45 Occ 83: Good 1998-03-21T04:35:00 45 Occ 85: Good 1998-03-21T16:41:40 15 Occ 86: Good 1998-03-22T04:47:00 45 Occ 87: Good 1998-03-22T16:41:35 15 Occ 88: Good 1998-03-23T04:38:15 45 Occ 89: Good 1998-03-23T16:27:40 15 Occ 90: Good 1998-03-24T04:15:05 45 Occ 91: Good 1998-03-24T16:00:15 15 Occ 92: Good