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 ---------------------------------------------------------------------------- ORB3200 170 118 953 1987-09-10T00:43:24.445Z 1987-09-10T01:28:22.462Z ORB3201 95 118 953 1987-09-11T00:44:10.962Z 1987-09-11T01:28:42.978Z ORB3202 107 118 953 1987-09-12T00:44:37.479Z 1987-09-12T01:29:09.495Z ORB3203 189 118 953 1987-09-13T00:44:45.996Z 1987-09-13T01:29:44.013Z ORB3204 94 118 953 1987-09-14T00:45:34.516Z 1987-09-14T01:30:04.532Z ORB3205 203 118 953 1987-09-15T00:45:43.034Z 1987-09-15T01:30:51.051Z ORB3206 70 118 953 1987-09-16T00:54:01.552Z 1987-09-16T01:24:15.563Z ORB3207 101 118 953 1987-09-17T00:46:50.072Z 1987-09-17T01:25:40.087Z ORB3208 108 118 953 1987-09-18T00:47:24.590Z 1987-09-18T01:32:20.607Z ORB3209 108 118 953 1987-09-19T00:47:53.105Z 1987-09-19T01:32:51.122Z ORB3210 215 118 953 1987-09-20T00:48:17.631Z 1987-09-20T01:33:13.647Z ORB3211 101 118 953 1987-09-21T00:48:54.148Z 1987-09-21T01:33:50.164Z ORB3212 215 118 953 1987-09-22T00:49:16.662Z 1987-09-22T01:34:14.678Z ORB3213 78 118 953 1987-09-23T00:56:15.171Z 1987-09-23T01:28:35.183Z ORB3214 157 118 953 1987-09-24T00:57:17.689Z 1987-09-24T01:35:19.702Z ORB3215 102 118 953 1987-09-25T00:51:14.195Z 1987-09-25T01:34:06.210Z ORB3216 93 118 953 1987-09-26T00:51:33.687Z 1987-09-26T01:36:03.703Z ORB3217 215 118 953 1987-09-27T00:51:59.186Z 1987-09-27T01:36:55.202Z ORB3218 107 118 953 1987-09-28T00:52:36.698Z 1987-09-28T01:37:08.715Z ORB3219 215 118 953 1987-09-29T00:53:15.217Z 1987-09-29T01:38:11.233Z ORB3220 91 118 953 1987-09-30T00:54:05.723Z 1987-09-30T01:32:19.731Z ORB3221 211 118 953 1987-10-01T00:54:19.236Z 1987-10-01T01:39:15.252Z ORB3222 107 118 953 1987-10-02T00:54:59.759Z 1987-10-02T01:39:31.775Z ORB3223 92 118 953 1987-10-03T00:55:30.265Z 1987-10-03T01:33:44.276Z ORB3224 214 118 953 1987-10-04T00:55:54.790Z 1987-10-04T01:40:50.807Z ORB3225 57 118 953 1987-10-05T00:56:31.315Z 1987-10-05T01:41:27.332Z ORB3226 215 118 953 1987-10-06T00:56:55.836Z 1987-10-06T01:42:05.852Z ORB3227 92 118 953 1987-10-07T00:57:38.359Z 1987-10-07T01:35:52.369Z ORB3228 215 118 953 1987-10-08T00:58:02.883Z 1987-10-08T01:42:58.899Z ORB3229 108 118 953 1987-10-09T00:58:39.405Z 1987-10-09T01:43:35.422Z ORB3230 91 118 953 1987-10-10T00:59:33.925Z 1987-10-10T01:37:21.931Z ORB3231 215 118 953 1987-10-11T00:59:30.444Z 1987-10-11T01:44:38.460Z ORB3232 106 118 953 1987-10-12T01:00:28.963Z 1987-10-12T01:45:00.980Z ORB3233 216 118 953 1987-10-13T01:00:25.484Z 1987-10-13T01:45:35.501Z ORB3234 76 118 953 1987-10-14T01:07:44.004Z 1987-10-14T01:39:14.015Z ORB3235 216 118 953 1987-10-15T01:01:22.518Z 1987-10-15T01:46:30.534Z ORB3236 107 118 953 1987-10-16T01:02:21.031Z 1987-10-16T01:46:53.047Z ORB3237 75 118 953 1987-10-17T01:09:55.547Z 1987-10-17T01:41:01.559Z ORB3238 206 118 953 1987-10-18T01:02:44.055Z 1987-10-18T01:48:04.071Z ORB3253 108 118 953 1987-11-02T01:08:32.562Z 1987-11-02T01:53:25.077Z ORB3254 240 118 953 1987-11-03T01:08:21.561Z 1987-11-03T01:53:41.075Z 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.