A new version of the subcollimator response table (SRT_20020522.dat) has
been uploaded and should appear in your ssw\hessi\dbase\grid_resp sub
directory as part of a subsequent update.  The new version includes
prelimary values of phases for grids 1 and 2 so as to enable imaging
with 2.3 arcseconds angular resolution.  Parameters for grids 3-9 are
the same as the current default.

A few comments...

*  Since coarser grids can be processed faster than finer grids, you may
notice that including grids 1 or 2 in your maps will esult in longer
processing times.

* Since a given grid only modulates source structure that is finer than
about the grid resolution, some bursts may not have fine enough spatial
structure to benefit from the use of grids 1 or 2.  Their inclusion in
such cases will not improve and may in fact slightly degrade the
mapping.  One option is to make preliminary maps first using grids 3 and
higher to see if there are any apparently unresolved sources.

* Note that since February, the grid 2 energy threshold has been set at
~20 keV, so it should not be used at energies below this.

* You may see artifacts unless the pixel size is chosen to be about 1/2
or less than the FWHM of the finest subcollimator used in the map.  This
means that if you use grid 2, the pixel size should not be larger than 2
arcseconds, and if you use grid 1, you should use 1 arcsecond pixels or
smaller.

* An example of a burst that benefits from the use of the finer grids is
the 2007 UT event on 25-March.

Please let me know if you encounter any problems.

Good luck!

gordon