L3_LON_LAT
Name
	L3_LON_LAT
Purpose
     
       This procedure opens the L3 files, and returns one days worth
      
       of data in a regularly gridded lon/lat array
  
 CATEGORY: SNOE, Database
Calling Sequence
     
       L3_LON_LAT, coords, yyyyddd, data, altitude=altitude
Inputs
     
       coords:  'geo' or 'mag'
      
       yyyyddd: the date of the data to return
Keyword Parameters
     
       ALTITUDE: Set this to the altitude (in kilometers) to
      
       use. Defaults to 106km.
Outputs
     
       data: An array
Procedure
	You can describe the foobar superfloatation method being used here.
	You might not need this section for your routine.
Example
     
       L3_LON_LAT, 'geo', 1998079, d, alt=106
Modification History
 
   Written by:	CAB; 1999.
  
   2002-09-01: KDM; /swap_if_big_endian, partial documentation
  
   2002-09-09; KDM; added _EXTRA=e to OPEN