var/da/da_ssmi/spemiss.inc

   1       subroutine spemiss(f,tk,theta,ssw,ev,eh)
   2 !     returns the specular emissivity of sea water for given freq. (GHz),
   3 !     temperature T (K), incidence angle theta (degrees), salinity (permil)
   4 !
   5 !     Returned values verified against data in Klein and Swift (1977) and
   6 !     against Table 3.8 in Olson (1987, Ph.D. Thesis)
   7 !
   8       real,intent(in   ) :: f,tk,theta
   9       real,intent(out  ) :: ev,eh
  10       real   epsr,epsi,ssw
  11
  12       real   tc,costh,sinth,rthet,tmp1r,tmp1i
  13       complex   etav,etah,eps,cterm1v,cterm1h,cterm2,cterm3v,cterm3h
  14 !
  15
  16       tc = tk - t_kelvin
  17       call epsalt(f,tc,ssw,epsr,epsi)
  18       eps = cmplx(epsr,epsi)
  19       etav = eps
  20       etah = (1.0,0.0)
  21       rthet = theta*0.017453292
  22       costh = cos(rthet)
  23       sinth = sin(rthet)
  24       sinth = sinth*sinth
  25       cterm1v = etav*costh
  26       cterm1h = etah*costh
  27       eps = eps - sinth
  28       cterm2 = csqrt(eps)
  29       cterm3v = (cterm1v - cterm2)/(cterm1v + cterm2)
  30       cterm3h = (cterm1h - cterm2)/(cterm1h + cterm2)
  31       tmp1r   =  real(cterm3v)
  32       tmp1i   = -aimag(cterm3v)
  33 !     ev = 1.0 - cabs(cterm3v)**2
  34       ev =  1.0 - (tmp1r*tmp1r+tmp1i*tmp1i)
  35
  36       eh = 1.0 - cabs(cterm3h)**2
  37
  38       end subroutine spemiss
  39 !
  40
  41
  42