PVO Ion Mass Spectrometer high-resolution data are stored in single-orbit ASCII files. All of the data files have the same internal structure, which is described by the single format file OIMSDATA.FMT. File structure characteristics which may vary from file to file (# of records, start/stop time, etc.) are described in the individual PDS label files (*.LBL). Columns in all data files: ======================================================= name type description ------------------------------------------------------- PVO TIME char Date and time in format YYDOY FSEC, where YY is the year, DOY is the day-of-year & FSEC is the decimal second-of-day DWELL int Dwell time (time interval between samples, msec) DWELL = (TIME - UT)*1000/(n-1) BITS int Telemetry bit rate LAT float Venusian Latitude LON float Venusian Longitude ALT float Altitude SZA float Solar Zenith Angle SHA float Solar Hour Angle
MASS1 int Mass of Sample 1 DEN1 float Number density of Sample 1 MASS2 int Mass of Sample 2 DEN2 float Number density of Sample 2 . . . . . . . . . MASS55 int Mass of Sample 55 DEN55 float Number density of Sample 55 The values 999 and 9.9999e+04 are the missing data values for mass and density respectively. The value 99999.999 is the missing data value for the second-of-day part of the time column. Negative values in a density column indicate flagged (unreliable) data values. Data Files (.TAB extension) The high-resolution data files on this disk are ASCII table files, each having 118 columns and record length 953 bytes. Information about the individual files (number of records, start and stop times, etc.) can be obtained from the PDS label file accompanying each *.TAB file. This label file has the same filename as the data file but with .TAB replaced by .LBL. List of data files: ============================================================================ Name Records Cols Len Start Stop ---------------------------------------------------------------------------- ORB1000 290 118 953 1981-09-01T01:29:57.872Z 1981-09-01T02:29:12.896Z ORB1001 531 118 953 1981-09-02T01:29:56.050Z 1981-09-02T02:29:46.726Z ORB1002 280 118 953 1981-09-03T01:29:50.280Z 1981-09-03T02:29:36.554Z ORB1003 295 118 953 1981-09-04T01:29:41.108Z 1981-09-04T02:29:20.132Z ORB1004 528 118 953 1981-09-05T01:29:29.083Z 1981-09-05T02:29:11.105Z ORB1005 295 118 953 1981-09-06T01:29:23.259Z 1981-09-06T02:29:16.282Z ORB1006 528 118 953 1981-09-07T01:29:12.834Z 1981-09-07T02:29:06.857Z ORB1007 289 118 953 1981-09-08T01:29:01.409Z 1981-09-08T02:28:47.432Z ORB1008 529 118 953 1981-09-09T01:28:56.286Z 1981-09-09T02:28:49.010Z ORB1009 287 118 953 1981-09-10T01:28:51.065Z 1981-09-10T02:28:36.340Z ORB1010 289 118 953 1981-09-11T01:28:30.397Z 1981-09-11T02:28:04.420Z ORB1011 533 118 953 1981-09-12T01:28:20.466Z 1981-09-12T02:28:05.995Z ORB1012 293 118 953 1981-09-13T01:28:12.052Z 1981-09-13T02:27:45.325Z ORB1013 406 118 953 1981-09-14T01:27:53.578Z 1981-09-14T02:27:45.906Z ORB1014 292 118 953 1981-09-15T01:27:39.963Z 1981-09-15T02:27:19.987Z ORB1015 531 118 953 1981-09-16T01:27:25.639Z 1981-09-16T02:27:15.318Z ORB1016 285 118 953 1981-09-17T01:27:22.876Z 1981-09-17T02:26:36.898Z ORB1017 427 118 953 1981-09-18T01:27:03.249Z 1981-09-18T02:26:44.976Z ORB1018 523 118 953 1981-09-19T01:26:45.489Z 1981-09-19T02:26:32.316Z ORB1019 240 118 953 1981-09-20T01:26:36.129Z 1981-09-20T02:15:52.148Z ORB1020 218 118 953 1981-09-21T01:26:14.200Z 1981-09-21T02:16:00.229Z ORB1021 437 118 953 1981-09-22T01:25:59.693Z 1981-09-22T02:25:48.817Z ORB1022 485 118 953 1981-09-23T01:25:49.082Z 1981-09-23T02:25:32.905Z ORB1023 317 118 953 1981-09-24T01:25:33.717Z 1981-09-24T02:25:17.990Z ORB1024 437 118 953 1981-09-25T01:25:15.039Z 1981-09-25T02:25:02.322Z ORB1025 468 118 953 1981-09-26T01:24:57.896Z 1981-09-26T02:23:41.420Z ORB1026 432 118 953 1981-09-27T01:24:47.845Z 1981-09-27T02:24:30.769Z ORB1027 453 118 953 1981-09-28T01:24:28.752Z 1981-09-28T02:24:15.876Z ORB1028 438 118 953 1981-09-29T01:24:14.216Z 1981-09-29T02:24:05.242Z ORB1029 520 118 953 1981-09-30T01:23:58.984Z 1981-09-30T02:23:43.611Z ORB1030 320 118 953 1981-10-01T01:23:42.107Z 1981-10-01T02:12:04.229Z ORB1031 431 118 953 1981-10-02T01:23:27.917Z 1981-10-02T02:23:15.349Z ORB1032 486 118 953 1981-10-03T01:23:13.792Z 1981-10-03T02:23:08.219Z ORB1034 457 118 953 1981-10-05T01:22:46.692Z 1981-10-05T02:22:37.471Z ORB1035 317 118 953 1981-10-06T01:22:33.875Z 1981-10-06T02:22:10.351Z ORB1036 385 118 953 1981-10-07T01:22:15.898Z 1981-10-07T02:21:55.973Z ORB1037 337 118 953 1981-10-08T01:22:01.372Z 1981-10-08T02:21:43.099Z ORB1038 440 118 953 1981-10-09T01:21:49.646Z 1981-10-09T02:21:39.574Z ORB1039 385 118 953 1981-10-10T01:21:34.785Z 1981-10-10T02:21:19.360Z ORB1040 344 118 953 1981-10-11T01:21:26.114Z 1981-10-11T02:20:35.739Z ORB1041 499 118 953 1981-10-12T01:21:07.667Z 1981-10-12T02:20:51.124Z ORB1042 380 118 953 1981-10-13T01:20:53.489Z 1981-10-13T02:20:35.516Z ORB1043 380 118 953 1981-10-14T01:20:44.875Z 1981-10-14T02:20:26.150Z ORB1044 429 118 953 1981-10-15T01:20:34.457Z 1981-10-15T02:20:21.389Z ORB1046 380 118 953 1981-10-17T01:20:09.245Z 1981-10-17T02:19:50.820Z ORB1047 381 118 953 1981-10-18T01:20:02.385Z 1981-10-18T02:19:52.959Z ORB1049 378 118 953 1981-10-20T01:19:49.668Z 1981-10-20T02:19:31.245Z ORB1050 379 118 953 1981-10-21T01:19:39.212Z 1981-10-21T02:19:21.388Z ORB1051 483 118 953 1981-10-22T01:19:29.305Z 1981-10-22T02:19:21.782Z ORB1052 472 118 953 1981-10-23T01:19:23.502Z 1981-10-23T02:19:06.432Z ORB1053 501 118 953 1981-10-24T01:19:14.632Z 1981-10-24T02:19:03.835Z ORB1054 485 118 953 1981-10-25T01:19:09.814Z 1981-10-25T02:19:00.241Z ORB1055 513 118 953 1981-10-26T01:19:01.307Z 1981-10-26T02:18:08.895Z ORB1056 518 118 953 1981-10-27T01:18:55.624Z 1981-10-27T02:18:43.553Z ORB1057 520 118 953 1981-10-28T01:18:52.576Z 1981-10-28T02:18:49.703Z ORB1058 511 118 953 1981-10-29T01:18:52.274Z 1981-10-29T02:18:37.606Z ORB1059 512 118 953 1981-10-30T01:18:46.377Z 1981-10-30T02:18:36.511Z ORB1060 521 118 953 1981-10-31T01:18:43.035Z 1981-10-31T02:18:40.162Z ORB1061 426 118 953 1981-11-01T01:18:46.518Z 1981-11-01T02:18:16.812Z ORB1062 560 118 953 1981-11-02T01:19:23.439Z 1981-11-02T02:18:04.966Z ORB1063 571 118 953 1981-11-03T01:18:41.845Z 1981-11-03T02:18:32.968Z ORB1064 571 118 953 1981-11-04T01:18:38.850Z 1981-11-04T02:18:36.176Z ORB1065 567 118 953 1981-11-05T01:18:39.550Z 1981-11-05T02:18:36.821Z ORB1066 528 118 953 1981-11-06T01:18:44.383Z 1981-11-06T02:14:42.329Z ORB1067 515 118 953 1981-11-07T01:18:44.938Z 1981-11-07T02:12:42.973Z ORB1068 549 118 953 1981-11-08T01:18:45.590Z 1981-11-08T02:18:36.916Z ORB1069 518 118 953 1981-11-09T01:18:47.034Z 1981-11-09T02:13:03.759Z ORB1070 571 118 953 1981-11-10T01:18:48.876Z 1981-11-10T02:18:46.301Z ORB1071 572 118 953 1981-11-11T01:18:51.515Z 1981-11-11T02:18:49.142Z ORB1072 567 118 953 1981-11-12T01:18:59.756Z 1981-11-12T02:18:50.979Z ORB1073 572 118 953 1981-11-13T01:18:59.592Z 1981-11-13T02:18:56.918Z ORB1074 514 118 953 1981-11-14T01:19:06.019Z 1981-11-14T02:12:57.955Z ORB1075 571 118 953 1981-11-15T01:19:13.662Z 1981-11-15T02:19:04.592Z ORB1077 571 118 953 1981-11-17T01:19:23.430Z 1981-11-17T02:19:14.357Z ORB1078 568 118 953 1981-11-18T01:19:27.051Z 1981-11-18T02:19:05.488Z ORB1091 567 118 953 1981-12-01T01:21:05.954Z 1981-12-01T02:20:38.070Z ORB1092 509 118 953 1981-12-02T01:27:18.785Z 1981-12-02T02:20:45.706Z ORB1093 567 118 953 1981-12-03T01:20:59.940Z 1981-12-03T02:20:50.967Z ORB1094 571 118 953 1981-12-04T01:21:04.789Z 1981-12-04T02:20:55.966Z ORB1095 572 118 953 1981-12-05T01:21:04.440Z 1981-12-05T02:21:01.765Z ORB1096 572 118 953 1981-12-06T01:21:08.338Z 1981-12-06T02:21:05.765Z ORB1097 548 118 953 1981-12-07T01:21:14.686Z 1981-12-07T02:19:06.068Z ORB1098 572 118 953 1981-12-08T01:21:16.893Z 1981-12-08T02:21:14.317Z ORB1099 569 118 953 1981-12-09T01:21:24.485Z 1981-12-09T02:21:15.511Z Catalog Files (.CAT extension) Catalog data, which includes instrument, dataset, mission and spacecraft descriptions, can be found in the *.CAT files in the CATALOG directory on this disk.