mirror of https://github.com/saitohirga/WSJT-X.git
18 lines
421 B
Fortran
18 lines
421 B
Fortran
subroutine geocentric(alat,elev,hlt,erad)
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implicit real*8 (a-h,o-z)
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! IAU 1976 flattening f, equatorial radius a
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f = 1.d0/298.257d0
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a = 6378140.d0
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c = 1.d0/sqrt(1.d0 + (-2.d0 + f)*f*sin(alat)*sin(alat))
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arcf = (a*c + elev)*cos(alat)
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arsf = (a*(1.d0 - f)*(1.d0 - f)*c + elev)*sin(alat)
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hlt = datan2(arsf,arcf)
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erad = sqrt(arcf*arcf + arsf*arsf)
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erad = 0.001d0*erad
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return
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end subroutine geocentric
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