Data Set Overview
    =================
      All PROFILE data are packaged by periapsis number for each
      aerobraking orbit. PROFILE data are provided at one second resolution
      in a table labeled Pyyy.tab where 'yyy' is the three digit periapsis
      number.
 
 
    Parameters
    ==========
      Time from periapsis:          Units = seconds
      Latitude:                     Units = degrees
      Longitude:                    Units = degrees
      Local Solar Time:             Units = hours
      Solar Zenith Angle:           Units = degrees
      Altitude for 1-sec. data:     Units = km
      Density, 1 sec.:              Units = kg/km**3
      Sigma 1 sec. density:         Units = kg/km**3
      Altitude for 39-sec. data:    Units = km
      Density, 39 sec.:             Units = kg/km**3
      Sigma 39 sec. density:        Units = kg/km**3
 
 
    Data
    ====
      For each orbit, PROFILE data consist of an n-by-11 array in the file
      Pyyy, where n is the number of seconds of data received during the
      aerobraking pass. Column 1 contains the time from periapsis. Columns
      2 through 11 contain Latitude, Longitude, Local Solar Time, Solar Zenith
      Angle, Altitude for 1 Second Density, 1 Second Density, Sigma for 1
      Second Density, Altitude for 39 Second Density, 39 sec. Density and
      Sigma for 39 Second Density.
 
 
    Processing
    ==========
      Accelerometer data were processed in the PROFILE stage through several
      steps and the entire process with examples is given in [TOLSONETAL2007]
      First, traditional Euler terms were removed body angular rates. During
      operations,no attempt was made to synchronize data or to remove the
      effects of thruster firings. Because of the considerable wave structure
      in the density data, which do not represent the 'mean' thermosphere, a
      second data set is also archived. A 39 point running mean of the 1
      second density is the final data product. Data are included for only
      those times following the final negative 1 sec. density inbound, and
      prior to the first negative density value outbound. These negative
      densities values arise due to the offsets and biases of the system at
      small accelerations.
 
 
    Coordinate System
    =================
      Latitude and longitude are in the IAU Mars Centered Mars Equatorial
      System. Altitude is above the IAU reference ellipsoid, with a=3396.19 km
      and f=0.005886.

Confidence Level Overview
    =========================
      Standard deviations on 1 sec. densities are based on the local noise on
      the data as determined by a seven point running mean. Standard
      deviations on the 39 sec. data are based on the square root of n law.
 
 
    Review
    ======
      Version 1 products are based on operational data sets which underwent
      orbit to orbit comparisons with navigation team and spacecraft team
      results, see TOLSONETAL2007.
 
 
    Data Coverage and Quality
    =========================
      Data coverage during an aerobraking pass varied throughout the mission.
      The nominal pass assured that sufficient data were recovered above 250
      km to calibrate the accelerometers both inbound and outbound.