Data Set Overview:The PV-OIMS high resolution dataset contains data from the OrbiterIon Mass Spectrometer (OIMS) experiment and orbit attitude data fororbits 1-5055, including data for the period periapsis +/- 30 minutesfor each orbit. The dataset is divided into multiple files whichcontain 1 orbit. The user should be able to easily get to any desiredorbit by selecting the appropriate file.Data:The data are provided in fixed length records (ASCII) with eachrecord consisting of 119 data elements totaling 843 bytes. Therecord structure is described below. Each record represents onecomplete OIMS experiment data cycle (normally 6.3 seconds but thistime can vary with the bit rate). Within each record there are 55samples of mass and the density associated with that mass. Thesequence of masses within a record will normally follow the OIMS'explore' mode, but this sequence may vary when the experiment isoccasionally in the 'explore-adapt' mode.To compute the time associated with a particular mass and density,the dwell time element (element 5) should be used along with the timeof day (element 3). The dwell time is time interval (milliseconds)between samples. Thus, for the 'Nth' sample, the time would becomputed as follows:TIME : UT : (N - 1) * DWELL/1000 (where UT is the time of day)The user should be aware that some of the densities have been coded.For example, the values 999 and 9.9999e+04 are the missing data valuesfor mass and density, respectively, for that point. (This can be dueto several reasons such as telemetry interference or a gap in thedata occurred.) Also, a negative value of density represents a'flagged' data point and should be used with caution.column type bytes description: :jdate int 5 date in format yyddd where dd is day of yearut float 9 seconds of daydwell int 6 time interval  between samplesbits int 6 telemetry rate in lat float 7 Venus latitude lon float 8 Venus longitude alt float 10 Altitude sza float 9 Solar Zenith Angle (Sun-Venus-PVO) .sha float 9 Solar Hour Angle .mass1 int 4 Mass of species number 1 .den1 float 10 Density of species 1 .mass2 int 4 Mass of species 2 .den2 float 10 Density of species 2 . . . . . . . . . . . . .mass55 int 4 Mass of species 55 .den55 float 10 Density of species 55 .

Bad data have been excluded orflagged by using negative values for density. Users should stilluse caution when interpreting these data. No error estimates forthe densities are provided.