PDS_VERSION_ID         = PDS3                                                 
RECORD_TYPE            = STREAM                                               
OBJECT                 = TEXT                                                 
  NOTE                 = "DIGITIZE.TXT file contains the convention used for  
  the articles in ESA SP-1077 which were digitized with ESA permission"       
  PUBLICATION_DATE     = 1994-12-31                                           
END_OBJECT                                                                    
END                                                                           
                                                                              
*****File DIGITIZE.TXT                                                        
                                                                              
                                                                              
                       Digitization Conventions                               
                       for the ESA Articles                                   
                                                                              
A number of conventions were introduced in the IHW articles referenced as     
the COMET HALLEY SUMMARY VOLUME (Sekanina, Z. 1991) to express mathematical   
symbols, chemical formulae, greek letters, scientific notation, physical      
units, and special printing symbols (such as italics).  These Archive         
conventions followed those generally found in the literature  and were used   
in the digitization of the series of articles from ESA SP-1066 and SP-1077.   
A short summary of these conventions follows:                                 
                                                                              
01. No capitals are allowed for Greek letters, which are spelled in English   
02. Symbols for parallel, perpendicular are written fully                     
03. Approximation signs are given by one tilde                                
04. Units are given as abbreviations, e.g., deg                               
05. Vector notation is written out specifically, e.g., momentum vector        
06. Chemical subscripts and superscipts (as prefix or suffix) are ascii       
07. Powers are indicated by **, with a negative power indicated by "-"        
08. Multiplication is shown by *, except in scientific notation               
09. Functional dependence is indicated by closed parentheses                  
10. Abbreviations for milli, mega, nano are written fully                     
11. Derivatives are given by symbols d/dt of a variable                       
12. Integrals and summations are written out, as are limits                   
13. Nested functional dependence is indicated by brackets                     
                                                                              
In addition, the citation of references and author credits was standardized   
to conform to ESA SP-1066.   The abbreviations for instruments or experiments 
were taken from ESA SP-1077 and SP-1066 articles; alternate names for the     
experiments, e.g.,  EPA (not EPONA) are listed in AAREADME.TXT.