subroutine rsload_strain (z, flz, m, n, bsx, bcx, crtdis, dismax, qexpg, gdim, grefct, cstr, qtr, quit)

 This procedure computes (ocean tide) surface loading effects.
 Specific observation components: Strain (units: micro, 1E-6)
     Physically different: NN-S, XX-S
     Returned by this routine: the projected compnents, Enn Eee Ene

 Method: Point mass convolution, refinement of ocean grid in the near-zone
 of a site. The loading kernel (Green's) function is of complex type
 in order to allow for visco-elastic earth models.

 In one run, rsload processes a number of sites, the three strain
 components, and one partial tide.

 Rsload can except an ocean area, either a spherical quadrangle or a rect-
 angular tangent plane, stereographically projected
 (keyword: regional area clipping).

 Clipping modes: Either skip the tide inside a spherical quadrangle.
                 Or skip the tide outside a spherical quadrangle.

 If the quadrangle outlines an area for which a plane tide model has been
 computed, weights in the overlapping zones can be used to paste the
 areas together. The weight array can be computed using Oload/m/olstm.f

 If a site is near the coast, the near-zone loading effect can be excepted
 for post-processing by OLMPP (keywords: (local) exception processing, post-
 processing). The excepted area is 3x3 or 5x5 load cells wide. The support
 information passed to OLMPP is from a 5x5 or 7x7 area, respectively, always
 with a site at the centre.
   This program does not retrieve the TOPO data though ! (Deferred TOPO
 processing is achieved with the new version of OLMPP.)
 
 Prerequisits:

 Observing sites in  /CSITE/ - to be set by calling program.
                               Associated BLOCK DATA in ols05.f

 Near zone load exception, announced
                  in /CXCPT/ - array element QXCPT(isite) to be set true by
                               calling program.
                               Associated BLOCK DATA included below.

 Tide model grid information (global, spherical models)
                  in /CRSAR/ - to set, use GETFLA or GETGOT or GETCRT or ...
                               Associated BLOCK DATA in ols04.f

 Area clip limits in /CRSWI/ - to be set by calling program.
                               Associated BLOCK DATA in ols04.f
                               Default: Use all global data.

 Local area overlap weights (plane models)
           in /CGWA/ and /CUGWA/ - to set, use GETGWA
                               to create, exec OLSTM.exp
                               Default: ignore.

 Refer to olsr01.fc-doc for documentation of the named common areas.
 
 Calling parameters:
 -------------------

 Z(M,N)        - complex - tide array, organized north (.,1) to south (.,N).
 FLZ(M,N)      - integer - land/sea flags, tested on { .eq.0 | .ne.0 }.
 BSX(M),BSY(M) - real*8  - work arrays.
 CRTDIS        - real    - distance limit [deg] for integrated Green's fct.
 DISMAX        - real    - max.distance [deg] for Green's fct. table.
 QEXPG         - logical - .true.:  Make a new Green's fct. table.
                           .false.: Use the currently available one.
                           returned: .false.
 GDIM          - integer - length of Green's table. 2*(GDIM+1) four-byte
                           words must be allocated in Blank Common.
 CSTR(3,mxs)   - complex - returned: loading effects Enn Eee Ene.
                           Units = u-strain.
                           mxs  is a hard-wired parameter: number of sites.
 QTR           - logical - Trace on.

 Blank Common:
 -------------
 To be allocated in Main:
       real*4 ctab,g
       common ctab, g(4*GDIM+2)
 GDIM must be 1000 at least.

 ctab        - real*4 - Look-up index distance scale; set by rsload.
 g           - real*4 - Green's table. Internal use: complex*8
 
     entry rsload_strain_pic (d1,d2,id3,id4,qq)

 
     entry rsload_strain_ortho (qq)
 
     entry rsload_strain_hires (ires)
 
     entry rsload_strain_amp (v)
 
     entry rsload_strain_skip_xcpt
 
     entry rsload_strain_init
 
     entry rsload_strain_warning (qq)