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29 lines
503 B
Fortran
29 lines
503 B
Fortran
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subroutine delsph(flat1,flon1,flat2,flon2,del)
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implicit none
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real,parameter:: R=6371.0
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REAL,parameter:: pi=3.1415926535898
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real flat1,flat2
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real flon1,flon2
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real del
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real dlat
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real dlon
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real lat1
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real lat2
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real a
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real c
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!dlat=(flat2-flat1)*pi/180
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!dlon=(flon2-flon1)*pi/180
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!lat1=flat1*pi/180
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!lat2=flat2*pi/180
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dlat=flat2-flat1
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dlon=flon2-flon1
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lat1=pi/2-flat1
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lat2=pi/2-flat2
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a=sin(dlat/2)*sin(dlat/2)+sin(dlon/2)*sin(dlon/2)*cos(lat1)*cos(lat2)
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c=2*atan2(sqrt(a),sqrt(1-a))
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del=R*c
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end subroutine
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