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subroutine da_effang_tl(ifreq,theta,gx2,sigma,effangv,effangh, & 1,2
TGL_gx2,TGL_sigma,TGL_effangv,TGL_effangh )
!--------------------------------------------------------------------------
! Purpose : Calculate the effective zenith angle of reflected microwave
! radiation at SSM/I frequencies for vertical and horizontal polarization
!
! Input :: TGL_gx2, TGL_sigma
! Output :: TGL_effangv,TGL_effangh,effangv,effangh
!--------------------------------------------------------------------------
implicit none
integer, intent(in) :: ifreq
real, intent(in) :: theta,gx2,sigma,TGL_gx2, TGL_sigma
real, intent(out) :: TGL_effangv,TGL_effangh,effangv,effangh
real c19v,c19h,c22v,c22h,c37v,c37h,c85v,c85h
real s19v(6),s19h(6),s22v(6),s22h(6), &
s37v(6),s37h(6),s85v(6),s85h(6)
real :: alnsig,gg,ggg,xd,xx
real :: z1,z2,z3,z4,z5,z6,alnthv
real :: y,dth,angh,angv,alnthh
real :: TGL_alnsig,TGL_gg,TGL_ggg,TGL_xd
real :: TGL_z1,TGL_z2,TGL_z3,TGL_z4,TGL_z5,TGL_z6,TGL_alnthv
real :: TGL_y,TGL_dth,TGL_angh,TGL_angv,TGL_xx,TGL_alnthh
data c19v,c19h,c22v,c22h,c37v,c37h,c85v,c85h &
/-.5108,.5306,-.5108,.5306,-.6931,.1823,-.9163,.3000/
data s19v /.225E+2,.698E+2,-.238E+2,-.648E+1,.402E+0,.262E+1/
data s19h /.743E+1,.507E+2,-.206E+2,-.191E+1,.648E-1,.291E+1/
data s22v /.249E+2,.701E+2,-.240E+2,-.714E+1,.405E+0,.256E+1/
data s22h /.498E+1,.442E+2,-.190E+2,-.129E+1,.803E-2,.277E+1/
data s37v /.215E+2,.573E+2,-.211E+2,-.670E+1,.443E+0,.253E+1/
data s37h /.869E+1,.571E+2,-.257E+2,-.302E+1,.237E+0,.386E+1/
data s85v /.116E+2,.263E+2,-.101E+2,-.358E+1,.270E+0,.175E+1/
data s85h /.736E+1,.568E+2,-.254E+2,-.248E+1,.196E+0,.387E+1/
if (trace_use) call da_trace_entry
("da_effang_tl")
if (gx2 .le. 0.0 .or. sigma .le. 0.0) then
effangv = theta
TGL_effangv = 0.0
effangh = theta
TGL_effangh = 0.0
return
end if
alnsig = alog(sigma)
if (abs(sigma) .gt. 0.0) then
TGL_alnsig = TGL_sigma/sigma
else
TGL_alnsig = 0.0
end if
gg = gx2*gx2
TGL_gg = 2.0*gx2*TGL_gx2
ggg = gg*gx2
TGL_ggg = TGL_gg*gx2 + gg*TGL_gx2
if (ifreq .eq. 1) then
xd = alnsig - c19v
TGL_xd = TGL_alnsig
xx = xd*xd
TGL_xx = 2.0*xd*TGL_xd
z1 = xx*ggg
TGL_z1 = TGL_xx*ggg + xx*TGL_ggg
z2 = xd*ggg
TGL_z2 = TGL_xd*ggg + xd*TGL_ggg
z3 = xd*gg
TGL_z3 = TGL_xd*gg + xd*TGL_gg
z4 = xx*gg
TGL_z4 = TGL_xx*gg + xx*TGL_gg
z5 = xx*gx2
TGL_z5 = TGL_xx*gx2 + xx*TGL_gx2
z6 = xd*gx2
TGL_z6 = TGL_xd*gx2 + xd*TGL_gx2
alnthv = s19v(1)*z1 + s19v(2)*z2 + s19v(3)*z3 + &
s19v(4)*z4 + s19v(5)*z5 + s19v(6)*z6
TGL_alnthv = s19v(1)*TGL_z1 + s19v(2)*TGL_z2 + s19v(3)*TGL_z3 + &
s19v(4)*TGL_z4 + s19v(5)*TGL_z5 + s19v(6)*TGL_z6
alnthv = alnthv + 3.611
xd = alnsig - c19h
TGL_xd = TGL_alnsig
xx = xd*xd
TGL_xx = 2.0*xd*TGL_xd
z1 = xx*ggg
TGL_z1 = TGL_xx*ggg + xx*TGL_ggg
z2 = xd*ggg
TGL_z2 = TGL_xd*ggg + xd*TGL_ggg
z3 = xd*gg
TGL_z3 = TGL_xd*gg + xd*TGL_gg
z4 = xx*gg
TGL_z4 = TGL_xx*gg + xx*TGL_gg
z5 = xx*gx2
TGL_z5 = TGL_xx*gx2 + xx*TGL_gx2
z6 = xd*gx2
TGL_z6 = TGL_xd*gx2 + xd*TGL_gx2
alnthh = s19h(1)*z1 + s19h(2)*z2 + s19h(3)*z3 + &
s19h(4)*z4 + s19h(5)*z5 + s19h(6)*z6
TGL_alnthh = s19h(1)*TGL_z1 + s19h(2)*TGL_z2 + s19h(3)*TGL_z3 + &
s19h(4)*TGL_z4 + s19h(5)*TGL_z5 + s19h(6)*TGL_z6
alnthh = alnthh + 3.611
else if (ifreq .eq. 2) then
xd = alnsig - c22v
TGL_xd = TGL_alnsig
xx = xd*xd
TGL_xx = 2.0*xd*TGL_xd
z1 = xx*ggg
TGL_z1 = TGL_xx*ggg + xx*TGL_ggg
z2 = xd*ggg
TGL_z2 = TGL_xd*ggg + xd*TGL_ggg
z3 = xd*gg
TGL_z3 = TGL_xd*gg + xd*TGL_gg
z4 = xx*gg
TGL_z4 = TGL_xx*gg + xx*TGL_gg
z5 = xx*gx2
TGL_z5 = TGL_xx*gx2 + xx*TGL_gx2
z6 = xd*gx2
TGL_z6 = TGL_xd*gx2 + xd*TGL_gx2
alnthv = s22v(1)*z1 + s22v(2)*z2 + s22v(3)*z3 + &
s22v(4)*z4 + s22v(5)*z5 + s22v(6)*z6
TGL_alnthv = s22v(1)*TGL_z1 + s22v(2)*TGL_z2 + s22v(3)*TGL_z3 + &
s22v(4)*TGL_z4 + s22v(5)*TGL_z5 + s22v(6)*TGL_z6
alnthv = alnthv + 3.611
! TGL_alnthv = TGL_alnthv
xd = alnsig - c22h
TGL_xd = TGL_alnsig
xx = xd*xd
TGL_xx = 2.0*xd*TGL_xd
z1 = xx*ggg
TGL_z1 = TGL_xx*ggg + xx*TGL_ggg
z2 = xd*ggg
TGL_z2 = TGL_xd*ggg + xd*TGL_ggg
z3 = xd*gg
TGL_z3 = TGL_xd*gg + xd*TGL_gg
z4 = xx*gg
TGL_z4 = TGL_xx*gg + xx*TGL_gg
z5 = xx*gx2
TGL_z5 = TGL_xx*gx2 + xx*TGL_gx2
z6 = xd*gx2
TGL_z6 = TGL_xd*gx2 + xd*TGL_gx2
alnthh = s22h(1)*z1 + s22h(2)*z2 + s22h(3)*z3 + &
s22h(4)*z4 + s22h(5)*z5 + s22h(6)*z6
TGL_alnthh = s22h(1)*TGL_z1 + s22h(2)*TGL_z2 + s22h(3)*TGL_z3 + &
s22h(4)*TGL_z4 + s22h(5)*TGL_z5 + s22h(6)*TGL_z6
alnthh = alnthh + 3.611
! TGL_alnthh = TGL_alnthh
else if (ifreq .eq. 3) then
xd = alnsig - c37v
TGL_xd = TGL_alnsig
xx = xd*xd
TGL_xx = 2.0*xd*TGL_xd
z1 = xx*ggg
TGL_z1 = TGL_xx*ggg + xx*TGL_ggg
z2 = xd*ggg
TGL_z2 = TGL_xd*ggg + xd*TGL_ggg
z3 = xd*gg
TGL_z3 = TGL_xd*gg + xd*TGL_gg
z4 = xx*gg
TGL_z4 = TGL_xx*gg + xx*TGL_gg
z5 = xx*gx2
TGL_z5 = TGL_xx*gx2 + xx*TGL_gx2
z6 = xd*gx2
TGL_z6 = TGL_xd*gx2 + xd*TGL_gx2
alnthv = s37v(1)*z1 + s37v(2)*z2 + s37v(3)*z3 + &
s37v(4)*z4 + s37v(5)*z5 + s37v(6)*z6
TGL_alnthv = s37v(1)*TGL_z1 + s37v(2)*TGL_z2 + s37v(3)*TGL_z3 + &
s37v(4)*TGL_z4 + s37v(5)*TGL_z5 + s37v(6)*TGL_z6
alnthv = alnthv + 3.611
! TGL_alnthv = TGL_alnthv
xd = alnsig - c37h
TGL_xd = TGL_alnsig
xx = xd*xd
TGL_xx = 2.0*xd*TGL_xd
z1 = xx*ggg
TGL_z1 = TGL_xx*ggg + xx*TGL_ggg
z2 = xd*ggg
TGL_z2 = TGL_xd*ggg + xd*TGL_ggg
z3 = xd*gg
TGL_z3 = TGL_xd*gg + xd*TGL_gg
z4 = xx*gg
TGL_z4 = TGL_xx*gg + xx*TGL_gg
z5 = xx*gx2
TGL_z5 = TGL_xx*gx2 + xx*TGL_gx2
z6 = xd*gx2
TGL_z6 = TGL_xd*gx2 + xd*TGL_gx2
alnthh = s37h(1)*z1 + s37h(2)*z2 + s37h(3)*z3 + &
s37h(4)*z4 + s37h(5)*z5 + s37h(6)*z6
TGL_alnthh = s37h(1)*TGL_z1 + s37h(2)*TGL_z2 + s37h(3)*TGL_z3 + &
s37h(4)*TGL_z4 + s37h(5)*TGL_z5 + s37h(6)*TGL_z6
alnthh = alnthh + 3.611
! TGL_alnthh = TGL_alnthh
else if (ifreq .eq. 4) then
xd = alnsig - c85v
TGL_xd = TGL_alnsig
xx = xd*xd
TGL_xx = 2.0*xd*TGL_xd
z1 = xx*ggg
TGL_z1 = TGL_xx*ggg + xx*TGL_ggg
z2 = xd*ggg
TGL_z2 = TGL_xd*ggg + xd*TGL_ggg
z3 = xd*gg
TGL_z3 = TGL_xd*gg + xd*TGL_gg
z4 = xx*gg
TGL_z4 = TGL_xx*gg + xx*TGL_gg
z5 = xx*gx2
TGL_z5 = TGL_xx*gx2 + xx*TGL_gx2
z6 = xd*gx2
TGL_z6 = TGL_xd*gx2 + xd*TGL_gx2
alnthv = s85v(1)*z1 + s85v(2)*z2 + s85v(3)*z3 + &
s85v(4)*z4 + s85v(5)*z5 + s85v(6)*z6
TGL_alnthv = s85v(1)*TGL_z1 + s85v(2)*TGL_z2 + s85v(3)*TGL_z3 + &
s85v(4)*TGL_z4 + s85v(5)*TGL_z5 + s85v(6)*TGL_z6
alnthv = alnthv + 3.611
! TGL_alnthv = TGL_alnthv
xd = alnsig - c85h
TGL_xd = TGL_alnsig
xx = xd*xd
TGL_xx = 2.0*xd*TGL_xd
z1 = xx*ggg
TGL_z1 = TGL_xx*ggg + xx*TGL_ggg
z2 = xd*ggg
TGL_z2 = TGL_xd*ggg + xd*TGL_ggg
z3 = xd*gg
TGL_z3 = TGL_xd*gg + xd*TGL_gg
z4 = xx*gg
TGL_z4 = TGL_xx*gg + xx*TGL_gg
z5 = xx*gx2
TGL_z5 = TGL_xx*gx2 + xx*TGL_gx2
z6 = xd*gx2
TGL_z6 = TGL_xd*gx2 + xd*TGL_gx2
alnthh = s85h(1)*z1 + s85h(2)*z2 + s85h(3)*z3 + &
s85h(4)*z4 + s85h(5)*z5 + s85h(6)*z6
TGL_alnthh = s85h(1)*TGL_z1 + s85h(2)*TGL_z2 + s85h(3)*TGL_z3 + &
s85h(4)*TGL_z4 + s85h(5)*TGL_z5 + s85h(6)*TGL_z6
alnthh = alnthh + 3.611
! TGL_alnthh = TGL_alnthh
end if
angv = 90.0 - exp(alnthv)
TGL_angv = - TGL_alnthv*exp(alnthv)
angh = 90.0 - exp(alnthh)
TGL_angh = - TGL_alnthh*exp(alnthh)
y = 1.0 - 28.0*gx2
TGL_y = - 28.0*TGL_gx2
if (y .lt. 0.0) then
y = 0.0
TGL_y = 0.0
end if
dth = (theta - 53.0)*y
TGL_dth = (theta - 53.0)*TGL_y
effangv = angv + dth
TGL_effangv = TGL_angv + TGL_dth
effangh = angh + dth
TGL_effangh = TGL_angh + TGL_dth
if (trace_use) call da_trace_exit("da_effang_tl")
end subroutine da_effang_tl