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subroutine da_xyll_default(XX,YY,XLAT,XLON),2
!-----------------------------------------------------------------------
! Purpose: calculates the latitudes and longitudes from the
! (x,y) location (dot) in the mesoscale grids.
! on entry :
! x : the coordinate in x (j)-direction.
! y : the coordinate in y (i)-direction.
!
! on exit :
! xlat : latitudes
! xlon : longitudes
!-----------------------------------------------------------------------
implicit none
real, intent(in) :: XX, YY
real, intent(out) :: XLAT,XLON
real :: flp, flpp, r, cell, cel1, cel2
real :: rcone_factor, psx, conv
real :: cntri, cntrj, x, y, xcntr
if (trace_use) call da_trace_entry
("da_xyll_default")
conv = 180.0 / pi
! seperate treatment for global fields
if (fg_format == fg_format_kma_global) then
xlat = yy * 180.0 /(coarse_jy-1) - 90.0
xlon = xx * 360.0 /(coarse_ix-1) - 180.0
return
end if
cntri = real(coarse_ix+1)/2.0
cntrj = real(coarse_jy+1)/2.0
xcntr = 0.0
! calculate x and y positions of grid
x = (xx - 0.5)*dsm/coarse_ds + start_x
y = (yy - 0.5)*dsm/coarse_ds + start_y
x = xcntr + (x-cntri)*coarse_ds
y = ycntr + (y-cntrj)*coarse_ds
! now calculate lat and lon of this point
if (map_projection.ne.3) then
if(y.eq.0.0) then
if (x.ge.0.0) flp = 90.0/conv
if (x.lt.0.0) flp = -90.0/conv
else
if (phic.lt.0.0)then
flp = atan2(x,y)
else
flp = atan2(x,-y)
end if
end if
flpp = (flp/cone_factor)*conv+xlonc
if (flpp.lt.-180.0) flpp = flpp + 360.0
if (flpp.gt.180.0) flpp = flpp - 360.0
xlon = flpp
! now solve for latitude
r = sqrt(x*x+y*y)
if (phic.lt.0.0) r = -r
if (map_projection.eq.1) then
cell = (r*cone_factor)/(earth_radius*sin(psi1))
rcone_factor = 1.0/cone_factor
cel1 = tan(psi1/2.0)*(cell)**rcone_factor
end if
if (map_projection.eq.2) then
cell = r/earth_radius
cel1 = cell/(1.0+cos(psi1))
end if
cel2 = atan(cel1)
psx = 2.0*cel2*conv
xlat = pole-psx
end if
! calculations for mercator lat,lon
if (map_projection.eq.3) then
xlon = xlonc + ((x-xcntr)/c2)*conv
if (xlon.lt.-180.0) xlon = xlon + 360.0
if (xlon.gt.180.0) xlon = xlon - 360.0
cell = exp(y/c2)
xlat = 2.0*(conv*atan(cell))-90.0
end if
if (trace_use) call da_trace_exit("da_xyll_default")
end subroutine da_xyll_default