Software SPD_CLIENT provides a library and several 
executables for implementing interface to slant path 
delay, atmosphere opacity and antenna temperature on 
client side and a client routines for computing path 
delay path for satellite or air-borne altimetry by
interacting with the SPD server.

1) Two are public routines are required for computing path delay
   using the time series of slant path delay expanded 
   over azimuth and elevation for a set of stations:

   SPD_LOAD_BSPD   -- load the data from a directory with expansion 
                      coefficients in bspd format
   SPD_INTRP_DELAY -- compute path delay by interpolation


   Executable spd_3d_toser transforms the expansion coefficients
   from ascii SPD format to binary BSPD format.

  Two example programs are provided:

spd_show -- example of computing path delay at a given epoch.

sob_show -- example of computing opacity and atmosphere brightness
            temperature at a given epoch.

2) Three public routines that are required for computing path 
   delay for altimetry:

   spd_cli_init     -- parsing control file, initialization, and 
                       checking whether the SPD server is running.
   
   spd_cli_get_2pd  -- sending request to compute path delay to
                       the SPD server, waiting for the response,
                       parsing the results.

   spd_cli_quit     -- deallocation of dynamic memory.

   These three routines can be called from Fortran, C, or MATLAB.

   Three examples are provided:

   spd_cli_example_fortran.f
   spd_cli_example_c.c
   spd_cli_example_fortran.f
  
3) Three public routines that are required for computing path 

   spd_res_intrp     --

   get_spd_res       --

   get_spd_res_azel  --

4) Include files:
  
   spd.i
   spd_local.i
   spc.h
