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 ---------------------------------------------------------------------------- ORB2405 129 118 953 1985-07-06T22:12:05.672Z 1985-07-06T22:32:15.727Z ORB2416 380 118 953 1985-07-17T22:15:00.750Z 1985-07-17T23:14:52.078Z ORB2419 381 118 953 1985-07-20T22:15:58.875Z 1985-07-20T23:15:49.430Z ORB2441 571 118 953 1985-08-11T22:19:29.070Z 1985-08-11T23:19:19.469Z ORB2442 286 118 953 1985-08-12T22:19:47.820Z 1985-08-12T23:19:38.836Z ORB2443 306 118 953 1985-08-13T22:43:06.711Z 1985-08-13T23:15:40.094Z ORB2444 280 118 953 1985-08-14T22:20:13.969Z 1985-08-14T23:20:04.984Z ORB2445 232 118 953 1985-08-15T22:20:40.539Z 1985-08-15T23:09:36.562Z ORB2456 184 118 953 1985-08-26T22:23:12.109Z 1985-08-26T23:22:43.672Z ORB2457 154 118 953 1985-08-27T22:44:30.719Z 1985-08-27T23:00:35.023Z ORB2458 162 118 953 1985-08-28T22:23:31.727Z 1985-08-28T23:23:04.734Z ORB2460 281 118 953 1985-08-30T22:28:26.109Z 1985-08-30T22:57:50.305Z ORB2489 237 118 953 1985-09-28T22:25:02.500Z 1985-09-28T23:24:53.516Z ORB2490 237 118 953 1985-09-28T22:25:02.500Z 1985-09-28T23:24:53.516Z ORB2491 96 118 953 1985-09-30T22:35:26.000Z 1985-09-30T22:50:23.430Z ORB2492 246 118 953 1985-10-01T22:25:07.688Z 1985-10-01T23:16:27.969Z ORB2494 216 118 953 1985-10-03T22:38:08.398Z 1985-10-03T23:03:26.758Z ORB2495 254 118 953 1985-10-04T22:25:11.562Z 1985-10-04T23:25:01.414Z ORB2496 244 118 953 1985-10-05T22:25:18.469Z 1985-10-05T23:25:02.711Z ORB2497 328 118 953 1985-10-06T22:25:14.266Z 1985-10-06T23:25:05.719Z ORB2498 241 118 953 1985-10-07T22:25:22.867Z 1985-10-07T23:25:04.117Z ORB2499 311 118 953 1985-10-08T22:38:50.219Z 1985-10-08T23:11:54.664Z 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.