subroutine ephem(mjd0,dut,east_long,geodetic_lat,height,nspecial, & RA,Dec,Az,El,techo,dop,fspread_1GHz,vr) implicit real*8 (a-h,o-z) real*8 jd !Time of observationa as a Julian Date real*8 mjd,mjd0 !Modified Julian Date real*8 prec(3,3) !Precession matrix, J2000 to Date real*8 rmatn(3,3) !Nutation matrix real*8 rme2000(6) !Vector from Earth center to Moon, JD2000 real*8 rmeDate(6) !Vector from Earth center to Moon at Date real*8 rmeTrue(6) !Include nutation real*8 raeTrue(6) !Vector from Earth center to Obs at Date real*8 rmaTrue(6) !Vector from Obs to Moon at Date logical km,bary,jplok !Set km=.true. to get km, km/s from ephemeris common/stcomx/km,bary,pvsun(6) !Common used in JPL subroutines common/librcom/xl(2),b(2) twopi=8.d0*atan(1.d0) !Define some constants rad=360.d0/twopi clight=2.99792458d5 au2km=0.1495978706910000d9 pi=0.5d0*twopi pio2=0.5d0*pi km=.true. freq=1000.0d6 do jj=1,2 mjd=mjd0 if(jj.eq.1) mjd=mjd - 1.d0/1440.d0 djutc=mjd jd=2400000.5d0 + mjd djtt=mjd + sla_DTT(jd)/86400.d0 ttjd=jd + sla_DTT(jd)/86400.d0 ! inquire(file='JPLEPH',exist=jplok) ! if(jplok) then if(nspecial.ne.8) then call pleph(ttjd,10,3,rme2000) !RME (J2000) from JPL ephemeris year=2000.d0 + (jd-2451545.d0)/365.25d0 call sla_PREC (2000.0d0, year, prec) !Get precession matrix rmeDate(1:3)=matmul(prec,rme2000(1:3)) !Moon geocentric xyz at Date rmeDate(4:6)=matmul(prec,rme2000(4:6)) !Moon geocentric vel at Date else call sla_DMOON(djtt,rmeDate) !No JPL ephemeris, use DMOON rmeDate=rmeDate*au2km endif if(nspecial.eq.7) then rmeTrue=rmeDate else !Nutation to true equinox of Date call sla_NUT(djtt,rmatn) call sla_DMXV(rmatn,rmeDate,rmeTrue) call sla_DMXV(rmatn,rmeDate(4),rmeTrue(4)) endif ! Local Apparent Sidereal Time: djut1=djutc + dut/86400.d0 if(nspecial.eq.6) djut1=djutc xlast=sla_DRANRM(sla_GMST(djut1) + sla_EQEQX(djtt) + east_long) call sla_PVOBS(geodetic_lat,height,xlast,raeTrue) rmaTrue=rmeTrue - raeTrue*au2km if(nspecial.ne.2) then ! Allow for planetary aberration tl=499.004782D0*SQRT(rmaTrue(1)**2 + rmaTrue(2)**2 + rmaTrue(3)**2) rmaTrue(1:3)=rmaTrue(1:3)-tl*rmaTrue(4:6)/au2km endif !Topocentric RA, Dec, dist, velocity call sla_DC62S(rmaTrue,RA,Dec,dist,RAdot,DECdot,vr) dop=-2.d0 * freq * vr/clight !EME doppler shift techo=2.d0*dist/clight !Echo delay time (s) call libration(jd,RA,Dec,xl(jj),b(jj)) enddo fspread_1GHz=0.0d0 dldt=57.2957795131*(xl(2)-xl(1)) dbdt=57.2957795131*(b(2)-b(1)) rate=sqrt((2*dldt)**2 + (2*dbdt)**2) fspread_1GHz=0.5*6741*rate call sla_DE2H(xlast-RA,Dec,geodetic_lat,Az,El) return end subroutine ephem