Harris Priester Drag File

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The Harris-Priester Drag file (harris_priester_density_tables.dat) provides the data file for 1964 Harris–Priester Atmospheric density modeling. This model bases the density profile on a specified flux level for the radiation at the 10.7 cm wavelength. A table of integral flux values (measured at F10.7 = 65, 75, 100, 125, 150, 175, 200, 225, 250, 275 x10-22 W/m2/Hz) provides the atmospheric density for altitudes between 110 and 2000 kilometers. The data file also provides constant density values below 110 km.

 

Note: This file is not time dependent. It is not updated with each FreeFlyer release.

 

Below is a semi log plot showing the atmospheric density changes as a function of altitude when using the Harris Priester model. The data for this plot was generated in FreeFlyer for the density profile on Jul 01 2012 00:00:00.000.

 

Plot of the atmospheric density as a function of altitude from 110 km to 2000 km. The data used for the plot was taken directly from the atmosden.dat file included with FreeFlyer.

Plot of the atmospheric density as a function of altitude from 110 km to 2000 km. The data used for the plot was taken directly from the atmosden.dat file included with FreeFlyer.

 

References:

1."Goddard Trajectory Determination System (GTDS) Mathematical Theory", FDD/552-89/001 and CSC/TR-89/6001, July 1989

 

 

Harris Priester Drag File Format


The format of the Harris Priester Drag file included with FreeFlyer installation is shown below.

 

   Harris-Priester Atmospheric Density Models File Layout

 

Logical Record Size = 1680 , Block size = 1680 , 9 blocks

--------------------------------------------------------------

Bytes      |   Desciption

--------------------------------------------------------------

1-1440     | DENSTY(I,J) I=1,3 ; J= 1,60

          |   Atmospheric Density Table

          |   I=1 : Altitude (km)

          |   I=2 : Minimum density (kg/km3)

          |   I=3 : Maximum density (km/km3)

1441-1512  | DESCR(I)  I=1,10

          |   Description of model

1513-1516  | MODNBR:  Model number

1517-1520  | NDENS: # of altitude entries in density table

              (upper bound of J subscript)

1521-1524  | NBRATM: Largest record number in use on file

1525-1528  | MAXATM: Maximum number of models permitted (=10)

1529-1536  | YMDHMS: Date of last maintenance performed

1537-1540  | IFLAG:  Last maintenance operation indicator

          |  =1, initialize

          |  =2, add

          |  =3, modify

          |  =4, delete

1541-1680  | Spares

-------------------------------------------------------------

 

File Summary Report of Contents

 

MODEL NUMBER:   1

NUMBER OF ENTRIES IN DENSITY ARRAY: 59

MODEL NAME: 1964 HARRIS/PRIESTER ATMOSPHERE (MIN-MAX) 0-2000 KM  F=65              

 

MODEL NUMBER:   2

NUMBER OF ENTRIES IN DENSITY ARRAY: 59

MODEL NAME: 1964 HARRIS/PRIESTER ATMOSPHERE (MIN-MAX) 0-2000 KM  F=75              

 

MODEL NUMBER:   3

NUMBER OF ENTRIES IN DENSITY ARRAY: 59

MODEL NAME: 1964 HARRIS/PRIESTER ATMOSPHERE (MIN-MAX) 0-2000 KM  F=100            

 

MODEL NUMBER:   4

NUMBER OF ENTRIES IN DENSITY ARRAY: 59

MODEL NAME: 1964 HARRIS/PRIESTER ATMOSPHERE (MIN-MAX) 0-2000 KM  F=125            

 

MODEL NUMBER:   5

NUMBER OF ENTRIES IN DENSITY ARRAY: 59

MODEL NAME: 1964 HARRIS/PRIESTER ATMOSPHERE (MIN-MAX) 0-2000 KM  F=150            

 

MODEL NUMBER:   6

NUMBER OF ENTRIES IN DENSITY ARRAY: 59

MODEL NAME: 1964 HARRIS/PRIESTER ATMOSPHERE (MIN-MAX) 0-2000 KM  F=175            

 

MODEL NUMBER:   7

NUMBER OF ENTRIES IN DENSITY ARRAY: 59

MODEL NAME: 1964 HARRIS/PRIESTER ATMOSPHERE (MIN-MAX) 0-2000 KM  F=200            

 

MODEL NUMBER:   8

NUMBER OF ENTRIES IN DENSITY ARRAY: 59

MODEL NAME: 1964 HARRIS/PRIESTER ATMOSPHERE (MIN-MAX) 0-2000 KM  F=225            

 

MODEL NUMBER:   9

NUMBER OF ENTRIES IN DENSITY ARRAY: 59

MODEL NAME: 1964 HARRIS/PRIESTER ATMOSPHERE (MIN-MAX) 0-2000 KM  F=250            

 

MODEL NUMBER:  10

NUMBER OF ENTRIES IN DENSITY ARRAY: 59

MODEL NAME: 1964 HARRIS/PRIESTER ATMOSPHERE (MIN-MAX) 0-2000 KM  F=275