Electron Density Coefficients File

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The Electron Density Coefficients data file (electron_density.dat) contains the ionospheric refraction generalized coefficients of the spherical harmonic expansions used in the computation of the maximum electron density and its associated altitude.

 

The maximum electron density and its associated altitude are used in the orbit determination process to correct the range, range rate and elevation measurements for the effects of atmospheric refraction.

 

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

 

File Format

The file contains a series of records, each 30780 bytes long:

•Bytes 1-4 contain the month and day for the start of the period covered by the record.

•Bytes 5-8 contain the month and day for the end of the period covered by the record.

•Bytes 9 - 23,720 contain the 2,964 coefficients used in the computation of the maximum electron density.

•Bytes 23,721 - 27,248 contain the 441 coefficients used in the computation of the associated altitude.

•Remaining bytes are spares

 

The format of the Electron Density Coefficients file is shown below.

 

      Ionospheric Refraction Generalized Coefficients File (GENCOF)

 

 

        All Records              Size=30780

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   Bytes     |  Description

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    1-4      | MDF:  Month and day for start of period covered by record

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    5-8      | MDL:  Month and day for end of period covered by record

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    9-23720  | W(I,J)  I=1,3  J=1,988

             | Generalized FOF2 coefficients

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 23721-27248 | UMO(I)  I=1,441

             | Generalized M (3000) F2 coefficients for sunspot=0

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 27249-30776 | UM100(I)  I=1,441

             | Generalized M (3000) F2 coefficients for sunspot=0

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 30777-30780 | Spare

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