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 ---------------------------------------------------------------------------- ORB3100 186 118 953 1987-06-02T00:11:36.290Z 1987-06-02T00:56:32.306Z ORB3101 73 118 953 1987-06-03T00:28:27.811Z 1987-06-03T00:39:48.054Z ORB3102 214 118 953 1987-06-04T00:12:41.844Z 1987-06-04T00:57:27.857Z ORB3103 224 118 953 1987-06-05T00:13:14.364Z 1987-06-05T00:58:13.629Z ORB3104 212 118 953 1987-06-06T00:13:49.374Z 1987-06-06T00:58:47.391Z ORB3105 202 118 953 1987-06-07T00:14:24.092Z 1987-06-07T00:59:20.109Z ORB3106 203 118 953 1987-06-08T00:14:57.617Z 1987-06-08T00:59:53.633Z ORB3107 186 118 953 1987-06-09T00:15:17.366Z 1987-06-09T01:00:13.383Z ORB3108 133 118 953 1987-06-10T00:30:21.231Z 1987-06-10T01:00:47.241Z ORB3109 207 118 953 1987-06-11T00:16:24.225Z 1987-06-11T01:01:08.242Z ORB3110 207 118 953 1987-06-12T00:16:56.731Z 1987-06-12T01:01:41.246Z ORB3111 221 118 953 1987-06-13T00:17:29.766Z 1987-06-13T01:02:15.032Z ORB3112 223 118 953 1987-06-14T00:18:01.553Z 1987-06-14T01:02:55.568Z ORB3113 226 118 953 1987-06-15T00:18:34.087Z 1987-06-15T01:03:20.101Z ORB3114 215 118 953 1987-06-16T00:19:06.626Z 1987-06-16T01:03:52.640Z ORB3115 75 118 953 1987-06-17T00:35:29.641Z 1987-06-17T00:47:09.422Z ORB3116 175 118 953 1987-06-18T00:19:59.698Z 1987-06-18T01:04:59.713Z ORB3117 200 118 953 1987-06-19T00:20:30.217Z 1987-06-19T01:05:29.482Z ORB3118 219 118 953 1987-06-20T00:20:59.970Z 1987-06-20T01:05:59.237Z ORB3119 219 118 953 1987-06-21T00:21:29.756Z 1987-06-21T01:06:29.022Z ORB3120 189 118 953 1987-06-22T00:21:57.542Z 1987-06-22T01:06:57.556Z ORB3121 219 118 953 1987-06-23T00:22:26.075Z 1987-06-23T01:07:26.091Z ORB3122 91 118 953 1987-06-24T00:22:54.608Z 1987-06-24T00:50:33.337Z ORB3123 217 118 953 1987-06-25T00:23:21.638Z 1987-06-25T01:08:20.904Z ORB3124 223 118 953 1987-06-26T00:23:49.405Z 1987-06-26T01:08:53.419Z ORB3160 141 118 953 1987-08-01T00:33:30.841Z 1987-08-01T01:18:20.854Z ORB3161 193 118 953 1987-08-02T00:33:07.352Z 1987-08-02T01:18:25.366Z ORB3162 125 118 953 1987-08-03T00:33:49.863Z 1987-08-03T01:18:36.377Z ORB3163 207 118 953 1987-08-04T00:33:26.848Z 1987-08-04T01:18:45.361Z ORB3164 94 118 953 1987-08-05T00:34:05.843Z 1987-08-05T01:18:05.856Z ORB3165 138 118 953 1987-08-06T00:33:56.350Z 1987-08-06T01:19:02.864Z ORB3166 54 118 953 1987-08-07T00:35:21.346Z 1987-08-07T01:15:51.860Z ORB3167 45 118 953 1987-08-08T00:36:14.355Z 1987-08-08T01:19:19.618Z ORB3168 139 118 953 1987-08-09T00:34:26.113Z 1987-08-09T01:19:23.379Z ORB3170 81 118 953 1987-08-11T00:39:27.638Z 1987-08-11T01:19:59.652Z ORB3171 2 118 953 1987-08-12T00:40:30.156Z 1987-08-12T00:41:20.156Z ORB3194 101 118 953 1987-09-04T00:41:19.417Z 1987-09-04T01:25:59.431Z ORB3195 81 118 953 1987-09-05T00:41:37.920Z 1987-09-05T01:26:17.934Z ORB3196 190 118 953 1987-09-06T00:41:30.409Z 1987-09-06T01:26:42.423Z ORB3197 95 118 953 1987-09-07T00:42:24.925Z 1987-09-07T01:26:54.941Z ORB3198 203 118 953 1987-09-08T00:42:29.412Z 1987-09-08T01:27:25.428Z ORB3199 69 118 953 1987-09-09T00:51:17.930Z 1987-09-09T01:21:57.940Z 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.