WSJT-X/lib/moondop.f90

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subroutine MoonDop(nyear,month,nday,uth4,lon4,lat4,RAMoon4, &
DecMoon4,LST4,HA4,AzMoon4,ElMoon4,vr4,dist4)
implicit real*8 (a-h,o-z)
real*4 uth4 !UT in hours
real*4 lon4 !West longitude, degrees
real*4 lat4 !Latitude, degrees
real*4 RAMoon4 !Topocentric RA of moon, hours
real*4 DecMoon4 !Topocentric Dec of Moon, degrees
real*4 LST4 !Locat sidereal time, hours
real*4 HA4 !Local Hour angle, degrees
real*4 AzMoon4 !Topocentric Azimuth of moon, degrees
real*4 ElMoon4 !Topocentric Elevation of moon, degrees
real*4 vr4 !Radial velocity of moon wrt obs, km/s
real*4 dist4 !Echo time, seconds
real*8 LST
real*8 RME(6) !Vector from Earth center to Moon
real*8 RAE(6) !Vector from Earth center to Obs
real*8 RMA(6) !Vector from Obs to Moon
real*8 rme0(6)
logical km
data rad/57.2957795130823d0/,twopi/6.28310530717959d0/
km=.true.
dlat=lat4/rad
dlong1=lon4/rad
elev1=200.d0
call geocentric(dlat,elev1,dlat1,erad1)
dt=100.d0 !For numerical derivative, in seconds
UT=uth4
! NB: geodetic latitude used here, but geocentric latitude used when
! determining Earth-rotation contribution to Doppler.
call moon2(nyear,month,nDay,UT-dt/3600.d0,dlong1*rad,dlat*rad, &
RA,Dec,topRA,topDec,LST,HA,Az0,El0,dist)
call toxyz(RA/rad,Dec/rad,dist,rme0) !Convert to rectangular coords
call moon2(nyear,month,nDay,UT,dlong1*rad,dlat*rad, &
RA,Dec,topRA,topDec,LST,HA,Az,El,dist)
call toxyz(RA/rad,Dec/rad,dist,rme) !Convert to rectangular coords
phi=LST*twopi/24.d0
call toxyz(phi,dlat1,erad1,rae) !Gencentric numbers used here!
radps=twopi/(86400.d0/1.002737909d0)
rae(4)=-rae(2)*radps !Vel of Obs wrt Earth center
rae(5)=rae(1)*radps
rae(6)=0.d0
do i=1,3
rme(i+3)=(rme(i)-rme0(i))/dt
rma(i)=rme(i)-rae(i)
rma(i+3)=rme(i+3)-rae(i+3)
enddo
call fromxyz(rma,alpha1,delta1,dtopo0) !Get topocentric coords
vr=dot(rma(4),rma)/dtopo0
RAMoon4=topRA
DecMoon4=topDec
LST4=LST
HA4=HA
AzMoon4=Az
ElMoon4=El
vr4=vr
dist4=dist
return
end subroutine MoonDop