***** File CDTREE.TXT                                                         
                                                                              
ROOT--I-----AAREADME.TXT (abstract of entire volume contents)                 
      I                                                                       
      I-----BROWSE-------BRWZINFO.TXT (describes BROWSE images)               
      I                  LSPN0868.HDR (header for Halley BROWSE image)        
      I                         *.IBG (Halley BROWSE image)                   
      I                         *.LBL (label for Halley BROWSE image)         
      I                         *.*                                           
      I                  LSPN4039.HDR (beginning of calibration BROWSE files) 
      I                         *.*                                           
      I                                                                       
      I-----C86JAN05-----COMPINFO.TXT (describes compressed comet images)     
      I                  LSPN0868.HDR (header for compressed Halley image)    
      I                         *.IMQ (compressed Halley image)               
      I                         *.LBL (label for compressed Halley image)     
      I                         *.*                                           
      I                                                                       
      I-----CALIB   -----CALINFO.TXT  (describes compressed CALIB images)     
      I                  LSPN4039.HDR (header for compressed CALIB image)     
      I                         *.IMQ (compressed CALIB image)                
      I                         *.LBL (label for compressed CALIB image)      
      I                         *.*                                           
      I                                                                       
      I-----DOCUMENT-----ACKNWLDG.TXT (acknowledgements of network, team)     
      I                  BROWSE.TXT   (explains MIDGET subsampling routine)   
      I                  BRWZINFO.TXT (describes BROWSE images)               
      I                  CALIB.TXT    (tables linking CALIB, Halley files)    
      I                  CALINFO.TXT  (describes compressed CALIB images)     
      I                  CDSTRUCT.TXT (lists block location, space allocation)
      I                  CDTREE.TXT   (schematic of directory structure)      
      I                  COMPINFO.TXT (describes compressed comet images)     
      I                  COMPRESS.TXT (explains PACKER compression routine)   
      I                  DECOMP.TXT   (discusses PC decompression program)    
      I                  EPHEM.TXT    (explains ephemeris, interpolation)     
      I                  FITSCOMP.TXT (FITS proposal for compressed data)     
      I                  FITSINFO.TXT (describes FITS and IHW keywords)       
      I                  IMAGFORM.TXT (shows split FITS and PDS reference)    
      I                  IMAGUIDE.TXT (guide to CD-ROM volume for images)     
      I                  INDXINFO.TXT (lists index tables and format)         
      I                  LSPNOBS.TXT  (lists contributing LSPN observatories) 
      I                  NETLARGE.TXT (explains FITS header information)      
      I                  OBSNTERP.TXT (explains OBSNTERP program)             
      I                  PATHTABL.TXT (explains path table fields)            
      I                  PDSINFO.TXT  (describes PDS labels for image data)   
      I                  PREVPIX.TXT  (pseudocode for compression in IDL)     
      I                  SOFTINFO.TXT (compendium of code and programs)       
      I                  VOLUME.TXT   (summary of data on CD-ROM volume)      
      I                                                                       
      I                                                                       
      I-----EPHEM--------EPHEM.TAB    (ephemeris tables for time range)       
      I                  EPHEM.TXT    (explains ephemeris, interpolation)     
      I                                                                       
      I-----INDEX--------CALIB.DBF    (dBASE III+ empty database file)        
      I                  CALIB.HDR    (FITS header describing .IDX file)      
      I                  CALIB.IDX    (table linking CALIB, comet images)     
      I                  CALIB.STR    ("structure" files for delimited table) 
      I                  CDSTRUCT.*   (lists block location, space allocation)
      I                  EPHEM.*      (ephemeris table for time range)        
      I                  INDXINFO.TXT (lists index tables and format)         
      I                  LSPNOBS.*    (lists contributing LSPN observatories) 
      I                  NETLARGE.*   (FITS keyword values for time range)    
      I                  PATHTABL.*   (contains volume and path information)  
      I                  STRUCT.DBF   (database of four fields)               
      I                                                                       
      I-----SOFTWARE--I--BROWSE---I--BROWSE.TXT   (explains MIDGET)           
      I               I           I                                           
      I               I           I--FORTRAN--MIDGET.FOR                      
      I               I                                                       
      I               I--COMPRESS-I--COMPRESS.TXT (explains PACKER)           
      I               I           I                                           
      I               I           I--FORTRAN--PACKER.FOR                      
      I               I           I                                           
      I               I           I--IDL------PREVPIX.PRO                     
      I               I                       PREVPIX.TXT (pseudocode)        
      I               I                                                       
      I               I--DECOMP---I--C--------DECOMP.C                        
      I               I           I           DO_DATA.C                       
      I               I           I           DO_DFILE.C                      
      I               I           I           DO_IFILE.C                      
      I               I           I           DO_OFILE.C                      
      I               I           I           HEADER.C                        
      I               I           I           MAKEFILE                        
      I               I           I           PCDECLSP.C                      
      I               I           I           PCDECLSP.COM                    
      I               I           I           PCDECLSP.PRJ                    
      I               I           I           PCDECLSP.RSP                    
      I               I           I           PCDECLSP.TXT                    
      I               I           I           PUTKEY.C                        
      I               I           I           XTENSION.C                      
      I               I           I                                           
      I               I           I--DECOMP.TXT   (explains PCDECLSP)         
      I               I           I                                           
      I               I           I--FORTRAN--DECOMP.FOR                      
      I               I           I                                           
      I               I           I--PCDECLSP.COM                             
      I               I           I                                           
      I               I--INTERP---I--C--------ARGCH.C                         
      I               I           I           INTERP.C                        
      I               I           I           OBSNTERP.C                      
      I               I           I                                           
      I               I           I--FORTRAN--ARGCH2.FOR                      
      I               I           I           INTERP.FOR                      
      I               I           I           JDATE.FOR                       
      I               I           I           OBSNTERP.FOR                    
      I               I           I                                           
      I               I           I--OBSNTERP.TXT (explains *NTERP)           
      I               I           I--PCNTERP.EXE                              
      I               I           I--VAXNTERP.EXE                             
      I               I                                                       
      I               I--SOFTINFO.TXT (compendium of code and programs)       
      I                                                                       
      I-----VOLDESC.SFD  (information according to CCSDS guidelines)