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 ---------------------------------------------------------------------------- ORB0400 375 118 953 1980-01-09T06:25:10.086Z 1980-01-09T07:25:01.852Z ORB0401 569 118 953 1980-01-10T06:31:18.100Z 1980-01-10T07:31:15.428Z ORB0402 523 118 953 1980-01-11T06:37:15.740Z 1980-01-11T07:32:04.510Z ORB0403 565 118 953 1980-01-12T06:43:07.895Z 1980-01-12T07:43:05.348Z ORB0405 488 118 953 1980-01-14T06:54:39.107Z 1980-01-14T07:45:47.328Z ORB0407 369 118 953 1980-01-16T07:05:53.064Z 1980-01-16T08:05:32.012Z ORB0408 505 118 953 1980-01-17T07:10:04.023Z 1980-01-17T08:03:18.131Z ORB0409 556 118 953 1980-01-18T07:14:01.254Z 1980-01-18T08:12:17.869Z ORB0410 547 118 953 1980-01-19T07:17:42.852Z 1980-01-19T08:15:02.496Z ORB0411 528 118 953 1980-01-20T07:21:26.289Z 1980-01-20T08:16:52.834Z ORB0412 393 118 953 1980-01-21T07:25:08.193Z 1980-01-21T08:06:23.939Z ORB0413 571 118 953 1980-01-22T07:28:42.500Z 1980-01-22T08:28:33.531Z ORB0414 340 118 953 1980-01-23T07:31:58.283Z 1980-01-23T08:27:44.555Z ORB0415 551 118 953 1980-01-24T07:33:56.102Z 1980-01-24T08:33:47.172Z ORB0416 462 118 953 1980-01-25T07:35:27.064Z 1980-01-25T08:24:29.135Z ORB0417 496 118 953 1980-01-26T07:36:41.199Z 1980-01-26T08:29:17.316Z ORB0418 556 118 953 1980-01-27T07:37:45.428Z 1980-01-27T08:36:58.750Z ORB0419 407 118 953 1980-01-28T07:38:35.510Z 1980-01-28T08:21:13.426Z ORB0420 562 118 953 1980-01-29T07:39:25.043Z 1980-01-29T08:38:19.365Z ORB0421 572 118 953 1980-01-30T07:39:55.971Z 1980-01-30T08:39:53.240Z ORB0422 558 118 953 1980-01-31T07:39:41.611Z 1980-01-31T08:38:42.182Z ORB0423 571 118 953 1980-02-01T07:39:07.383Z 1980-02-01T08:38:58.494Z ORB0424 571 118 953 1980-02-02T07:38:15.822Z 1980-02-02T08:38:06.986Z ORB0425 560 118 953 1980-02-03T07:37:11.375Z 1980-02-03T08:35:53.137Z ORB0426 571 118 953 1980-02-04T07:36:02.564Z 1980-02-04T08:35:53.498Z ORB0427 569 118 953 1980-02-05T07:34:41.994Z 1980-02-05T08:34:26.695Z ORB0428 498 118 953 1980-02-06T07:33:24.623Z 1980-02-06T08:25:35.598Z ORB0429 544 118 953 1980-02-07T07:38:19.283Z 1980-02-07T08:35:51.756Z ORB0430 515 118 953 1980-02-08T07:43:07.387Z 1980-02-08T08:37:11.906Z ORB0431 571 118 953 1980-02-09T07:47:58.891Z 1980-02-09T08:47:49.832Z ORB0432 560 118 953 1980-02-10T07:52:41.201Z 1980-02-10T08:51:22.934Z ORB0433 492 118 953 1980-02-11T07:57:23.652Z 1980-02-11T08:49:15.818Z ORB0434 553 118 953 1980-02-12T08:02:00.184Z 1980-02-12T09:00:22.955Z ORB0435 344 118 953 1980-02-13T08:06:32.562Z 1980-02-13T09:06:20.586Z ORB0437 472 118 953 1980-02-15T08:15:24.221Z 1980-02-15T09:04:51.592Z ORB0438 563 118 953 1980-02-16T08:19:46.447Z 1980-02-16T09:18:46.980Z ORB0439 506 118 953 1980-02-17T08:24:07.443Z 1980-02-17T09:19:02.363Z ORB0440 512 118 953 1980-02-18T08:28:17.598Z 1980-02-18T09:21:56.746Z ORB0441 512 118 953 1980-02-19T08:32:28.410Z 1980-02-19T09:32:25.035Z ORB0442 476 118 953 1980-02-20T08:36:39.742Z 1980-02-20T09:35:47.520Z ORB0443 471 118 953 1980-02-21T08:40:40.438Z 1980-02-21T09:40:33.652Z ORB0494 569 118 953 1980-04-12T10:28:54.152Z 1980-04-12T11:28:51.484Z ORB0495 572 118 953 1980-04-13T10:28:46.148Z 1980-04-13T11:28:43.398Z ORB0496 475 118 953 1980-04-14T10:28:39.930Z 1980-04-14T11:28:37.309Z ORB0497 554 118 953 1980-04-15T10:28:33.656Z 1980-04-15T11:26:43.816Z ORB0498 572 118 953 1980-04-16T10:28:12.059Z 1980-04-16T11:28:09.387Z ORB0499 571 118 953 1980-04-17T10:26:58.129Z 1980-04-17T11:26:55.301Z 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.