subroutine azdist(grid1,grid2,utch,nAz,nEl,nDmiles,nDkm,nHotAz,nHotABetter) character*(*) grid1,grid2 character*6 MyGrid,HisGrid,mygrid0,hisgrid0 real*8 utch,utch0 logical HotABetter,IamEast real eltab(22),daztab(22) data eltab/18.,15.,13.,11.,9.,8.,7.,6.,5.3,4.7,4.,3.3,2.7, & 2.,1.5,1.,0.8,0.6,0.4,0.2,0.0,0.0/ data daztab/21.,18.,16.,15.,14.,13.,12.,11.,10.7,10.3,10., & 10.,10.,10.,10.,10.,10.,9.,9.,9.,8.,8./ data mygrid0/" "/,hisgrid0/" "/,utch0/-999.d0/ save MyGrid=grid1 HisGrid=grid2 if(ichar(grid1(5:5)).eq.0) MyGrid(5:6)=' ' if(ichar(grid2(5:5)).eq.0) HisGrid(5:6)=' ' if(MyGrid.eq.HisGrid) then naz=0 nel=0 ndmiles=0 ndkm=0 nhotaz=0 nhotabetter=1 go to 999 endif if(mygrid.eq.mygrid0 .and. hisgrid.eq.hisgrid0 .and. & abs(utch-utch0).lt.0.1666667d0) go to 900 utch0=utch mygrid0=mygrid hisgrid0=hisgrid utchours=utch if(MyGrid(5:5).eq.' ') MyGrid(5:5)='m' if(MyGrid(6:6).eq.' ') MyGrid(6:6)='m' if(HisGrid(5:5).eq.' ') HisGrid(5:5)='m' if(HisGrid(6:6).eq.' ') HisGrid(6:6)='m' if(MyGrid.eq.HisGrid) then Az=0. Dmiles=0. Dkm=0.0 El=0. HotA=0. HotB=0. HotABetter=.true. go to 900 endif call grid2deg(MyGrid,dlong1,dlat1) call grid2deg(HisGrid,dlong2,dlat2) eps=1.e-6 if(abs(dlat1-dlat2).lt.eps .and. abs(dlong1-dlong2).lt.eps) then Az=0. Dmiles=0. Dkm=0.0 El=0. HotA=0. HotB=0. HotABetter=.true. go to 900 else call geodist(dlat1,dlong1,dlat2,dlong2,Az,Baz,Dkm) endif ndkm=Dkm/100 j=ndkm-4 if(j.lt.1) j=1 if(j.gt.21)j=21 if(Dkm.lt.500.0) then El=18.0 else u=(Dkm-100.0*ndkm)/100.0 El=(1.0-u)*eltab(j) + u*eltab(j+1) endif daz=daztab(j) + u * (daztab(j+1)-daztab(j)) Dmiles=Dkm/1.609344 tmid=mod(UTChours-0.5*(dlong1+dlong2)/15.0+48.0,24.0) IamEast=.false. if(dlong1.lt.dlong2) IamEast=.true. if(dlong1.eq.dlong2 .and. dlat1.gt.dlat2) IamEast=.false. azEast=baz if(IamEast) azEast=az if((azEast.ge.45.0 .and. azEast.lt.135.0) .or. & (azEast.ge.225.0 .and. azEast.lt.315.0)) then ! The path will be taken as "east-west". HotABetter=.true. if(abs(tmid-6.0).lt.6.0) HotABetter=.false. if((dlat1+dlat2)/2.0 .lt. 0.0) HotABetter=.not.HotABetter else ! The path will be taken as "north-south". HotABetter=.false. if(abs(tmid-12.0).lt.6.0) HotABetter=.true. endif if(IamEast) then HotA = Az - daz HotB = Az + daz else HotA = Az + daz HotB = Az - daz endif if(HotA.lt.0.0) HotA=HotA+360.0 if(HotA.gt.360.0) HotA=HotA-360.0 if(HotB.lt.0.0) HotB=HotB+360.0 if(HotB.gt.360.0) HotB=HotB-360.0 900 continue naz=nint(Az) nel=nint(el) nDmiles=nint(Dmiles) nDkm=nint(Dkm) nHotAz=nint(HotB) nHotABetter=0 if(HotABetter) then nHotAz=nint(HotA) nHotABetter=1 endif 999 return end subroutine azdist