c****************************************************************

	subroutine convert_sch_to_xyz(ptm,r_schv,r_xyzv,i_type)

c****************************************************************
c**
c**	FILE NAME: convert_sch_to_xyz.for
c**
c**     DATE WRITTEN:1/15/93 
c**
c**     PROGRAMMER:Scott Hensley
c**
c** 	FUNCTIONAL DESCRIPTION: This routine applies the affine matrix 
c**     provided to convert the sch coordinates xyz WGS-84 coordintes or
c**     the inverse transformation.
c**
c**     ROUTINES CALLED:latlon,matvec
c**  
c**     NOTES: none
c**
c**     UPDATE LOG:
c**
c*****************************************************************

       	implicit none

c	INPUT VARIABLES:

c	structure /pegtrans/          !transformation parameters
c	   real*8 r_mat(3,3)
c	   real*8 r_matinv(3,3)
c	   real*8 r_ov(3)
c	   real*8 r_radcur
c	end structure
c	record /pegtrans/ ptm

	type pegtrans
          sequence
	  real (8) r_mat(3,3)
	  real (8) r_matinv(3,3)
	  real (8) r_ov(3)
	  real (8) r_radcur
        end type pegtrans
	type (pegtrans) ptm

        real*8 r_schv(3)              !sch coordinates of a point
        real*8 r_xyzv(3)              !WGS-84 coordinates of a point
        integer i_type                !i_type = 0 sch => xyz ; 
                                      !i_type = 1 xyz => sch
   
c   	OUTPUT VARIABLES: see input

c	LOCAL VARIABLES:
        integer i_t
        real*8 r_schvt(3),r_llh(3)
c	structure /ellipsoid/ 
c	   real*8 r_a        
c	   real*8 r_e2
c	end structure
c	record /ellipsoid/ sph

	type ellipsoid
           sequence
	   real (8) r_a        
	   real (8) r_e2
	end type ellipsoid
	type (ellipsoid) sph

c	DATA STATEMENTS:

C	FUNCTION STATEMENTS:none

c  	PROCESSING STEPS:

c       compute the linear portion of the transformation 

	sph%r_a = ptm%r_radcur
	sph%r_e2 = 0.0d0

	if(i_type .eq. 0)then

	   r_llh(1) = r_schv(2)/ptm%r_radcur
	   r_llh(2) = r_schv(1)/ptm%r_radcur
	   r_llh(3) = r_schv(3)

           i_t = 1
           call latlon(sph,r_schvt,r_llh,i_t)
           call matvec(ptm%r_mat,r_schvt,r_xyzv)
           call lincomb(1.d0,r_xyzv,1.d0,ptm%r_ov,r_xyzv)           

        elseif(i_type .eq. 1)then

	   call lincomb(1.d0,r_xyzv,-1.d0,ptm%r_ov,r_schvt)
           call matvec(ptm%r_matinv,r_schvt,r_schv)
           i_t = 2
           call latlon(sph,r_schv,r_llh,i_t)
 
           r_schv(1) = ptm%r_radcur*r_llh(2)
           r_schv(2) = ptm%r_radcur*r_llh(1)
           r_schv(3) = r_llh(3)

	endif

	end