------------------------------------------------------------------------
FILE: README.usage
AUTHOR: Ken Mankoff (mankoff (at) lasp (dot) colorado (dot) edu)
LOCATION: LASP, University of Colorado
DATE: 2002-05-28

------------------------------------------------------------------------
Introduction

This file attempts to describe how to use the Mariner Mars 1971
Reflectance Database. See README.processing for a detailed explanation
of how the database was generated.

See README.albatross to learn about software built to aid in the
visualization of this data.

------------------------------------------------------------------------
Usage Example

Algorithm in IDL code:
(Goal: Return all records surrounding Mount Olympus (Nix Olympica))
IDL> @mm71_setup
IDL> LUT_load, lut
IDL> indices = where( lut.lat GT 15  AND $
                      lut.lat LT 20  AND $
                      lut.lon GT 130 AND $
                      lut.lon LT 140, $
                      count )
IDL> reflectanceDB_struct, record
IDL> recs = REPLICATE( record, count )
IDL> OPENR, 1, 'reflectanceDB.dat'
IDL> data = assoc( 1, record )
IDL> FOR i=0,count-1 do recs[i] = data[indices[i]]
IDL> plot, recs[0].reflectance


Algorithm in English:
1) Pre-compile all necessary routines
2) Load the Lookup Table. This is done into a struct by default. If
   you prefer to work with an ASSOC() BYTARR() or FLTARR(), read
   LUT_load.pro.
3) Use WHERE() on the LUT parameters to select a subset of the entire
   reflectanceDB.dat database (i.e. lat/lon to select on location, DAS
   to select on time, etc.)
4) Use the indices returned by WHERE() to access those same records
   from the reflectanceDB.dat database (use a FOR loop).


Algorithm using Albatross Visualization Software:
1) Download and install Albatross 
   http://lasp.colorado.edu/albatross/
2) Load the desired region of the surface. Return all footprints in
   the region via the "reflectance" keyword
   IDL> albatross, loc=[ 18, 133 ], size=30, /NO_MOTION, refl=refl
3) IDL> help, refl, /st
4) data = refl.reflectance

------------------------------------------------------------------------
EOF