ISCE_INSAR/components/isceobj/Util/Library/geometry/src/tcnbasis.F

43 lines
996 B
Fortran

!c****************************************************************
subroutine tcnbasis(pos,vel,elp,r_t,r_c,r_n)BIND(C,NAME='tcnbasis_C')
use linalg3module
implicit none
!c INPUT VARIABLES:
real(C_DOUBLE), dimension(3) :: pos
real(C_DOUBLE), dimension(3) :: vel
type (ellipsoidType) elp
!c OUTPUT VARIABLES:
real(C_DOUBLE), dimension(3) :: r_c, r_t, r_n
!c LOCAL VARIABLES:
real*8 tvt, tvc,tvn, r_a, r_e2, lat, lon, rad
real*8 r_temp(3),r_llh(3)
integer i
!c compute a TCN basis vector set
call latlon(elp,pos,r_llh,XYZ_2_LLH)
lat = r_llh(1)
lon = r_llh(2)
rad = r_llh(3)
r_n(1) = -cos(lat)*cos(lon)
r_n(2) = -cos(lat)*sin(lon)
r_n(3) = -sin(lat)
call cross(r_n,vel,r_temp)
call unitvec(r_temp,r_c)
call cross(r_c,r_n,r_temp)
call unitvec(r_temp,r_t)
end subroutine tcnbasis