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 ---------------------------------------------------------------------------- ORB2801 396 118 953 1986-08-06T23:06:33.562Z 1986-08-07T00:06:26.270Z ORB2802 72 118 953 1986-08-07T23:29:57.922Z 1986-08-07T23:41:08.898Z ORB2803 421 118 953 1986-08-08T23:06:41.016Z 1986-08-09T00:06:33.201Z ORB2804 411 118 953 1986-08-09T23:06:44.477Z 1986-08-10T00:06:36.290Z ORB2805 410 118 953 1986-08-10T23:06:47.070Z 1986-08-11T00:06:39.001Z ORB2806 412 118 953 1986-08-11T23:06:48.750Z 1986-08-12T00:06:41.051Z ORB2807 365 118 953 1986-08-12T23:06:50.836Z "UNK" ORB2808 351 118 953 1986-08-13T23:06:51.320Z 1986-08-14T00:06:43.795Z ORB2809 236 118 953 1986-08-14T23:24:36.570Z 1986-08-15T00:06:44.193Z ORB2810 341 118 953 1986-08-15T23:06:51.812Z 1986-08-16T00:06:37.785Z ORB2811 228 118 953 1986-08-16T23:23:52.094Z 1986-08-17T00:06:43.614Z ORB2812 37 118 953 1986-08-17T23:09:53.617Z 1986-08-17T23:13:40.305Z ORB2813 389 118 953 1986-08-18T23:06:50.109Z 1986-08-19T00:06:42.245Z ORB2814 396 118 953 1986-08-19T23:06:48.484Z 1986-08-20T00:06:40.644Z ORB2815 402 118 953 1986-08-20T23:06:46.086Z 1986-08-21T00:06:38.654Z ORB2816 73 118 953 1986-08-21T23:30:03.539Z 1986-08-21T23:41:24.070Z ORB2817 402 118 953 1986-08-22T23:06:41.133Z 1986-08-23T00:06:35.671Z ORB2818 397 118 953 1986-08-23T23:06:38.711Z 1986-08-24T00:06:31.219Z ORB2819 397 118 953 1986-08-24T23:06:36.430Z 1986-08-25T00:06:28.765Z ORB2820 393 118 953 1986-08-25T23:06:33.680Z 1986-08-26T00:06:26.315Z ORB2821 383 118 953 1986-08-26T23:06:31.070Z 1986-08-27T00:06:23.359Z ORB2822 366 118 953 1986-08-27T23:06:28.062Z 1986-08-28T00:06:20.385Z ORB2859 366 118 953 1986-10-03T23:07:44.812Z 1986-10-04T00:07:36.833Z ORB2860 362 118 953 1986-10-04T23:07:56.164Z 1986-10-05T00:07:50.114Z ORB2861 341 118 953 1986-10-05T23:08:09.195Z 1986-10-06T00:08:01.252Z ORB2862 188 118 953 1986-10-06T23:08:22.070Z 1986-10-06T23:28:25.500Z ORB2865 323 118 953 1986-10-09T23:09:03.156Z 1986-10-10T00:08:55.796Z ORB2866 339 118 953 1986-10-10T23:09:17.203Z 1986-10-11T00:09:09.646Z ORB2868 333 118 953 1986-10-12T23:09:49.438Z 1986-10-13T00:09:41.763Z ORB2869 367 118 953 1986-10-13T23:10:09.125Z 1986-10-14T00:10:01.120Z ORB2872 354 118 953 1986-10-16T23:11:02.328Z 1986-10-17T00:10:54.574Z ORB2873 358 118 953 1986-10-17T23:11:19.727Z 1986-10-18T00:11:11.906Z ORB2875 344 118 953 1986-10-19T23:11:57.609Z 1986-10-20T00:11:36.227Z ORB2881 103 118 953 1986-10-25T23:13:48.391Z 1986-10-25T23:44:48.641Z ORB2882 93 118 953 1986-10-26T23:14:11.508Z 1986-10-26T23:23:50.820Z ORB2883 93 118 953 1986-10-27T23:14:27.430Z 1986-10-27T23:24:06.742Z ORB2884 93 118 953 1986-10-28T23:14:48.258Z 1986-10-28T23:24:27.570Z ORB2886 6 118 953 1986-10-30T23:43:40.633Z 1986-10-30T23:50:57.625Z ORB2891 5 118 953 1986-11-04T23:16:58.766Z 1986-11-04T23:17:23.953Z ORB2892 9 118 953 1986-11-05T23:40:55.969Z 1986-11-05T23:50:31.969Z ORB2893 336 118 953 1986-11-06T23:17:33.945Z 1986-11-07T00:17:20.076Z ORB2894 342 118 953 1986-11-07T23:17:51.625Z 1986-11-08T00:17:37.596Z ORB2895 148 118 953 1986-11-08T23:18:08.578Z 1986-11-08T23:40:50.219Z ORB2896 92 118 953 1986-11-09T23:18:24.719Z 1986-11-09T23:27:58.047Z ORB2897 324 118 953 1986-11-10T23:18:46.852Z 1986-11-11T00:18:39.092Z ORB2899 3 118 953 1986-11-12T23:46:48.336Z 1986-11-12T23:47:07.812Z 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.