***** File BRWZINFO.TXT                                                       
                                                                              
     This directory contains uncompressed, subsampled browse images of Comet  
Giacobini-Zinner (P/G-Z).  The data were obtained by the Large-Scale Phenomena
                                                                              
Network.                                                                      
                                                                              
     In order to provide a uniform set of images which can be displayed       
quickly with the hardware currently available, a set of "browse images" has   
been generated of all L-SP comet digital data.  These images                  
were created by the subsampling program MIDGET.FOR (refer to the FORTRAN      
subdirectory of the SOFTWARE directory), and have a maximum size of 256 by 256
                                                                              
pixels, a strategy adopted to permit a minimum simultaneous display of four   
images on many standard (512x512) display devices.  The digital data have been
                                                                              
scaled into a numerical range of 0 to 255 (a single byte per pixel; the       
precision of the original images was 10 bits, or two bytes per pixel).        
                                                                              
     The FITS headers for the browse images contain the information present in
the headers for the full-resolution images, but NAXIS1, NAXIS2, and the       
astrometric keywords have been updated to reflect changes in the pixel spacing
and scale of the images.  In other words, it is possible to perform (degraded)
astrometry directly using the FITS headers accompanying these browse images.  
Also, HISTORY keyword lines have been inserted into the FITS headers to       
document the linear scale and density scale changes.                          
                                                                              
     The filename extension for files of browse data (.IBG = image, .HDR =    
header, .LBL = label) follow the IHW filename conventions.  To reconstruct the
original FITS byte stream, the .HDR and the .IBG files for the the appropriate
observation must be concatenated.