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 ---------------------------------------------------------------------------- ORB2900 293 118 953 1986-11-13T23:19:31.297Z 1986-11-14T00:19:29.781Z ORB2901 335 118 953 1986-11-14T23:19:48.633Z 1986-11-15T00:19:41.156Z ORB2902 214 118 953 1986-11-15T23:20:02.336Z 1986-11-16T00:14:51.958Z ORB2904 325 118 953 1986-11-17T23:20:32.883Z 1986-11-18T00:19:59.810Z ORB2905 5 118 953 1986-11-18T23:43:55.109Z 1986-11-18T23:53:40.844Z ORB2939 241 118 953 1986-12-22T23:46:02.180Z 1986-12-23T00:22:50.453Z ORB2940 76 118 953 1986-12-23T23:45:33.742Z 1986-12-23T23:57:22.102Z ORB2941 72 118 953 1986-12-24T23:45:42.461Z 1986-12-24T23:57:21.609Z ORB2942 74 118 953 1986-12-25T23:46:00.508Z 1986-12-25T23:57:30.023Z ORB2943 408 118 953 1986-12-26T23:23:08.594Z 1986-12-27T00:23:00.666Z ORB2945 430 118 953 1986-12-28T23:23:07.203Z 1986-12-29T00:22:53.208Z ORB2947 74 118 953 1986-12-30T23:46:10.977Z 1986-12-30T23:57:41.195Z ORB2948 72 118 953 1986-12-31T23:46:12.789Z 1986-12-31T23:57:42.766Z ORB2949 66 118 953 1987-01-01T23:46:24.844Z 1987-01-01T23:57:45.367Z ORB2953 63 118 953 1987-01-05T23:46:40.266Z 1987-01-05T23:58:10.523Z ORB2955 365 118 953 1987-01-07T23:23:36.852Z "UNK" ORB2956 71 118 953 1987-01-08T23:51:13.414Z "UNK" ORB2957 7 118 953 1987-01-09T23:57:22.656Z 1987-01-09T23:58:19.375Z ORB2958 406 118 953 1987-01-10T23:23:54.516Z 1987-01-11T00:23:52.428Z ORB2959 477 118 953 1987-01-11T23:24:02.297Z 1987-01-12T00:23:48.068Z ORB2960 489 118 953 1987-01-12T23:24:10.117Z 1987-01-13T00:24:02.426Z ORB2961 72 118 953 1987-01-13T23:47:37.852Z 1987-01-13T23:58:49.023Z ORB2962 408 118 953 1987-01-14T23:24:27.484Z 1987-01-15T00:24:19.513Z ORB2963 443 118 953 1987-01-15T23:24:36.492Z "UNK" ORB2964 75 118 953 1987-01-16T23:48:41.508Z 1987-01-17T00:04:13.513Z ORB2965 267 118 953 1987-01-17T23:24:58.039Z 1987-01-18T00:24:40.516Z ORB2966 392 118 953 1987-01-18T23:25:09.562Z 1987-01-19T00:25:01.989Z ORB2967 459 118 953 1987-01-19T23:25:21.453Z 1987-01-20T00:25:16.988Z ORB2968 75 118 953 1987-01-20T23:45:57.047Z 1987-01-21T00:15:46.492Z ORB2969 140 118 953 1987-01-21T23:44:56.039Z 1987-01-22T00:09:01.005Z ORB2970 75 118 953 1987-01-22T23:45:52.586Z 1987-01-23T00:09:10.528Z ORB2971 94 118 953 1987-01-23T23:45:55.109Z 1987-01-24T00:25:43.055Z ORB2972 446 118 953 1987-01-24T23:26:30.039Z 1987-01-25T00:26:25.592Z ORB2973 75 118 953 1987-01-25T23:42:29.203Z 1987-01-26T00:13:35.217Z ORB2974 13 118 953 1987-01-26T23:41:53.242Z 1987-01-26T23:43:47.242Z ORB2975 74 118 953 1987-01-27T23:43:28.281Z 1987-01-28T00:14:08.293Z ORB2976 156 118 953 1987-01-28T23:42:15.312Z 1987-01-29T00:07:27.324Z ORB2977 288 118 953 1987-01-29T23:27:53.039Z 1987-01-30T00:27:51.262Z ORB2978 289 118 953 1987-01-30T23:28:12.039Z 1987-01-31T00:28:09.589Z ORB2979 427 118 953 1987-01-31T23:28:29.953Z 1987-02-01T00:28:24.522Z ORB2986 364 118 953 1987-02-07T23:30:51.195Z 1987-02-08T00:30:38.865Z ORB2987 312 118 953 1987-02-08T23:31:12.188Z 1987-02-09T00:31:02.014Z ORB2988 151 118 953 1987-02-09T23:46:06.227Z 1987-02-10T00:10:16.234Z ORB2989 72 118 953 1987-02-10T23:47:23.758Z 1987-02-11T00:17:12.172Z ORB2990 156 118 953 1987-02-11T23:44:41.891Z 1987-02-12T00:09:55.302Z ORB2991 75 118 953 1987-02-12T23:46:50.805Z 1987-02-13T00:17:54.820Z ORB2992 233 118 953 1987-02-13T23:32:57.516Z 1987-02-14T00:32:50.233Z ORB2993 255 118 953 1987-02-14T23:33:48.070Z 1987-02-15T00:33:12.890Z ORB2994 232 118 953 1987-02-15T23:33:41.539Z 1987-02-16T00:33:34.109Z ORB2996 76 118 953 1987-02-17T23:47:49.883Z 1987-02-18T00:19:19.895Z ORB2997 228 118 953 1987-02-18T23:34:42.570Z 1987-02-19T00:34:35.890Z 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.