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subroutine da_spemiss_tl(f,tk,theta,ssw,ev,eh,TGL_tk,TGL_ev,TGL_eh ) 1,3
!-----------------------------------------------------------------------
! Purpose: returns the specular emissivity of sea water for given
! freq. (GHz), temperature T (K), incidence angle theta (degrees),
! salinity (permil)
!
! Returned values verified against data in Klein and Swift (1977) and
! against Table 3.8 in Olson (1987, Ph.D. Thesis)
!
! Input : TGL_tk
! Output : TGL_ev, TGL_eh, ev, eh
!------------------------------------------------------------------------
implicit none
real, intent(in) :: f, tk, theta, TGL_tk
real, intent(inout) :: ssw
real, intent(out) :: TGL_ev, TGL_eh, ev, eh
real :: epsr,epsi,TGL_epsr,TGL_epsi
real :: tc,costh,sinth,rthet
complex :: etav,etah,eps,cterm1v,cterm1h,cterm2,cterm3v,cterm3h,epsnew
complex :: TGL_etav,TGL_eps,TGL_cterm1v,TGL_cterm2,TGL_cterm3v
complex :: TGL_cterm3h,TGL_epsnew
! complex uniti
real :: tmp1r,tmp1i,tmp2r,tmp2i
! real :: rnorm,tmp0i,tmp0r
real :: TGL_tc,TGL_tmp1r
! real :: TGL_tmp0r,TGL_tmp0i,TGL_rnorm
real :: TGL_tmp1i,TGL_tmp2r,TGL_tmp2i
if (trace_use) call da_trace_entry
("da_spemiss_tl")
tc = tk - t_kelvin
TGL_tc = TGL_tk
call da_epsalt_tl(f,tc,ssw,epsr,epsi,TGL_tc, TGL_epsr, TGL_epsi )
eps = cmplx(epsr,epsi)
TGL_eps = cmplx(TGL_epsr,TGL_epsi)
etav = eps
TGL_etav = TGL_eps
etah = (1.0,0.0)
rthet = theta*0.017453292
costh = cos(rthet)
sinth = sin(rthet)
sinth = sinth*sinth
cterm1v = etav*costh
TGL_cterm1v = TGL_etav*costh
cterm1h = etah*costh
epsnew = eps - sinth
TGL_epsnew = TGL_eps
cterm2 = csqrt(epsnew)
! calculate TGL_cterm2
if (cabs(epsnew) .gt. 0.0) then
TGL_cterm2 = TGL_epsnew*0.5/cterm2
else
TGL_cterm2 = 0.0
end if
! Wei's Comment
! It is not a standard fortran if statement here.
! if (0) then
! tmp0r = real(epsnew)
! TGL_tmp0r = real(TGL_epsnew)
! tmp0i = -aimag(epsnew)
! TGL_tmp0i = -aimag(TGL_epsnew)
! rnorm = sqrt(tmp0r*tmp0r+tmp0i*tmp0i)
! uniti = (0,1)
! if (rnorm .gt. 0.0) then
! if (abs(tmp0i) .gt. 0.0) then
! TGL_rnorm = (tmp0r*TGL_tmp0r + tmp0i*TGL_tmp0i)/rnorm
! TGL_cterm2= cterm2*0.5*(TGL_rnorm/rnorm &
! -uniti*(TGL_tmp0r*rnorm-TGL_rnorm*tmp0r)/(rnorm*tmp0i))
! else
! TGL_rnorm = TGL_tmp0r
! TGL_cterm2= TGL_tmp0r*0.5/sqrt(tmp0r)
! end if
! else
! TGL_rnorm = 0.0
! TGL_cterm2= 0.0
! end if
! end if
! End Wei's Comment
cterm3v = (cterm1v - cterm2)/(cterm1v + cterm2)
TGL_cterm3v = (TGL_cterm1v - TGL_cterm2)/(cterm1v + cterm2) &
-cterm3v*(TGL_cterm1v + TGL_cterm2)/(cterm1v + cterm2)
cterm3h = (cterm1h - cterm2)/(cterm1h + cterm2)
TGL_cterm3h = -TGL_cterm2/(cterm1h + cterm2) &
-cterm3h*TGL_cterm2/(cterm1h + cterm2)
tmp1r = real(cterm3v)
TGL_tmp1r = real(TGL_cterm3v)
tmp1i = -aimag(cterm3v)
TGL_tmp1i = -aimag(TGL_cterm3v)
! ev = 1.0 - cabs(cterm3v)**2
ev = 1.0 - (tmp1r*tmp1r+tmp1i*tmp1i)
TGL_ev = -2.0*tmp1r*TGL_tmp1r - 2.0*tmp1i*TGL_tmp1i
tmp2r = real(cterm3h)
TGL_tmp2r = real(TGL_cterm3h)
tmp2i = -aimag(cterm3h)
TGL_tmp2i = -aimag(TGL_cterm3h)
! eh = 1.0 - cabs(cterm3h)**2
eh = 1.0 - (tmp2r*tmp2r+tmp2i*tmp2i)
TGL_eh = -2.0*tmp2r*TGL_tmp2r - 2.0*tmp2i*TGL_tmp2i
if (trace_use) call da_trace_exit("da_spemiss_tl")
end subroutine da_spemiss_tl