Chapter 9 (Updated): Models for atmospheric propagation delays

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Updates

  • 10 June 2013:
    • The subroutine GPT2.F has been updated for consistency with the version at TU Wien. This version ensures proper function at the South pole [1], and the parameter "dmjd" is no longer modified by the subroutine [2]. A reference has been added in the Chapter 9 text.
  • 15 January 2013:
    • Introduce the model Global Pressure and Temperature 2 in sections 9.2 "Tropospheric model for radio techniques" and 9.3 "Sources for meteorological data". [3]
    • In the section 9.4 "Ionospheric models for radio techniques", correct some numerical values in a number of equations for using exact CODATA (2010) values of fundamental constants.[4] Changes are not significant with respect to the uncertainties of the quantities.
  • 10 August 2012:
    Changes with respect to previous version of the chapter:
    • In the section 9.2 "Tropospheric model for radio techniques", correct a typo in the Chen and Herring gradient mapping function.
    • In the section 9.4.1 "Ionospheric delay dependence on radio signals including higher order terms", the part "Ray bending effects on geometric path excess and ionospheric delay" has been updated.[5]
  • 26 March 2012:
    • The test case provided for the subroutine VMF1.F has been corrected. The subroutine VMF1_HT.F has been corrected for an error in the computation of the quantity VMF1H [6] and for the test case.
  • 25 November 2011:
    • The header of the subroutine GPT.F has been corrected for the test case output. [7]

Software

  • FCUL_A.F - Function to compute the global total FCULa mapping function, dependent on latitude, height, and surface temperature. [8]
  • FCUL_B.F - Function to compute the global total FCULb mapping function, dependent on latitude, height and day of year. [8]
  • FCUL_ZD_HPA.F - Subroutine to compute the Mendes-Pavlis zenith total delay, for optical wavelengths, valid for infrared to ultraviolet.[8]
  • GMF.F - Subroutine to compute the Global Mapping Functions, GMF. [3]
  • VMF1.F - Subroutine to compute the Vienna Mapping Functions 1, VMF1, to be used with "a" coefficients computed for a given site.[3] (Updated March 26, 2012)
  • VMF1_HT.F - Subroutine to compute the Vienna Mapping Functions 1, VMF1, with height corrections, to be used with "a" coefficients computed for a grid. [3] (Updated March 26, 2012)
  • GPT.F - Subroutine to compute the Global Pressure and Temperature, based on spherical harmonics up to degree and order 9. [3]
  • GPT2.F - Subroutine to compute the Global Pressure and Temperature 2 model, and the "a" coefficients for VMF1_HT.F, based on the file gpt2_5.grd. [3] (Updated June 10, 2013)
  • APG.F - Subroutine to compute the asymmetric delay d in meter caused by gradients. The north and east gradients are also provided, based on spherical harmonics up to degree and order 9.[3]

Additional Information


[1] Noted by Changyong He

[2] Noted by D. Ferguson

[3] Provided by J. Boehm

[4] Noted by R. Langley

[5] Provided by E. Petrie and M. Hernandez Pajares

[6] Noted by J. McCarthy

[7] Noted by Ian Martin

[8] Provided by V. Mendes