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                            OBSDES DOCUMENTATION

                               SEPTEMBER 1986

I.  USER DOCUMENTATION - for general processing

    OBSDES compares a horizontal Blue Book Description data set  with its
respective Blue Book Observation data set .  OBSDES produces a list of error
messages along with the description data set record and observation data set
information.  The latter may consist of observation data set station names,
state or country codes, measured distances and directions which fail to
match the description data set record.  End of file messages may precede
the error messages and a summary of all observation data set control point
record SSN's and station names for which a description or recovery note was
not found may follow the error messages.

    Observation data set distance information consists of record sequence
numbers, measured distances and distance codes.  Direction information
consists of sequence numbers, set numbers, visibility codes and directions.
Mark-to-mark distances are reduced to sea level and directions may be
derived from combined lists if necessary.

    It is assumed that the observation data set and description data set
have been successfully run through CHKOBS and CHKDES respectively and all
syntax and structure errors have been resolved.

    This version is based on the Federal Geodetic Control Committee publi-
cation Input and Specifications of the National Geodetic Survey Data Base
(Blue Book), vol. I, chapters two and three, (1980, reprint 1982) as of
September 1986.


 A.  INPUT

     1.  An input Blue Book Description data set file.
         - on a PC the filename is entered in the interactive mode.

     2.  An input Blue Book Observation data set file.
         - on a PC the filename is entered in the interactive mode.

 B.  OUTPUT

     Program output error messages.
     - on a PC this may be printed and/or written to a file.  This
     option along with the output filename is entered in the interactive
     mode.
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     This is an example of a program output from a successful run:

                             NATIONAL GEODETIC SURVEY
 PROGRAM OBSDES  COMPARE A BLUE BOOK DESC DATA SET WITH ITS RESPECTIVE BLUE BOOK
                                OBS DATA SET


                                VERSION   1.0

 PROCESSING INPUT FILES - A:C9OBS                         A:C9DES
 DATE -  9/ 2/1986
 TIME -    7:  22

 000140*30*D05NBARE 1931 RM 1                NNWH 45.56 13.891           2373849
    770                                                 13.885 T
     90                                                          2 R 237 38 47.0
 CC 55-61 MATCHED DISTANCE IN METERS > 3 MM, CC 73-80 MATCHED DIRECTION > 1 SEC

 000460*14*CAPE ELIZABETH LT                       *15*AT/BARREN ISLANDS
           CAPE ELIZABETH LIGHT                        AK
 CC 11-50 STATION NAME AND CC 58-59 STATE CODE UNMATCHED

 001910*30*D05NVAN                          ENE              A8.655 KM  08329420
    350                                                          2 V  83 29 40.0
    362                                                          3 V  83 29 45.0
 CC 73-80 MATCHED DIRECTION > 1 SEC

 001920*30*D75NSANDRA RM 1                   W  H 21.62                  2975746
    791                                                  6.561 T
    792                                                  6.562 T
    793                                                  6.563 T
 CC 49-54 MATCHED DISTANCE IN FEET > 3 MM

 002350*30*D05NSUD 1931 RM 2                 ESEH 55.63 16.955           0830112
 CC 15-44 SUBSEQUENT 30 RECORD REFERENCE OBJECT NAME UNMATCHED

 002365*30*    SUD 1931 RM 1                    H       21.500
    771                                                 20.500 T
 CC 55-61 MATCHED DISTANCE IN METERS > 3 MM

 002367*30*    BARE 1930
 CC 15-44 FIRST REFERENCE OBJECT ENDPOINT NAME UNMATCHED--BY-PASS SECOND


 002371*30*    SUD 1931 RM 2                    H       20.500
 CC 15-44 SECOND REFERENCE OBJECT ENDPOINT NAME UNMATCHED

 002950*30*D05NGATE 1930                    SSWV             A2.482 KM  00000000
 CC 15-44 LEADING 30 RECORD REFERENCE OBJECT NAME UNMATCHED--BY-PASS SUBSEQUENT
                             30 RECORDS.
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 THE FOLLOWING BLUE BOOK OBS 80,81 RECORDS DO NOT HAVE A DESCRIPTION OR RECOVERY NOTE
 SSN      STATION NAME

 009      DRAG TP
 032      SHAG TP
 033      SKI TP

Execution terminated : PROGRAM OBSDES FINISHED

     An unsuccessful run may occur from an I/O error and not have any
     output.  Examples of an unsuccessful run due to I/O errors:

     "ERROR IN OPENING BLUE BOOK DESC DATA SET FILE - (filename)
      EXECUTION TERMINATED"
     Possible resolution:  incorrect filename entered

     "ERROR IN OPENING BLUE BOOK OBS DATA SET FILE - (filename)
      EXECUTION TERMINATED"
     Possible resolution: incorrect filename entered

     "ERROR IN OPENING PROGRAM OUTPUT FILE - (filename)
      EXECUTION TERMINATED"
     Possible resolution:  This should be a new file and should not exist
     prior to this run, there may be a duplicate filename.

     An unsuccessful run may also occur due to incorrect observation and/
     or description data sets.  Review the CHKOBS and CHKDES runs for
     syntax and structure errors.

 C.  EXECUTING OBSDES

 On a PC -

     Hardware requirements:

     a.  At least one floppy disk drive and a hard disk
                         or
         two floppy disk drives.
     b.  At least 268K of main memory
     c.  The 8087 math co-processor.
     d.  A printer (80 characters/line).

     The user will be supplied with a floppy disk containing one file:
 OBSDES.EXE.  The user should load this onto the PC's hard disk (this
 need only be done once if it permanently resides there).  If you do not
 have a hard disk, put this floppy disk in your default drive.

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To execute -

Type OBSDES

When prompted by the lines:

"IF YOU WANT HARD COPY THEN TURN PRINTER ON VIA KEYBOARD
 CONTINUE  (Y/N) ? "

To turn on printer:
On an IBM/XT, hit <CTRL> and <PrtSc> keys simultaneously.

Then respond to continue and when prompted by the line:

"ENTER INPUT BLUE BOOK OBS DATA SET INPUT FILENAME - "

Type in the filename of the input observation data set (include disk
drive designation if it is not on the hard disk).  Example:

ENTER BLUE BOOK OBS DATA SET INPUT FILENAME - A:C9OBS

Then when prompted by the line:

"ENTER BLUE BOOK DESC DATA SET INPUT FILENAME - "

Type in the filename of the input description data set.  Example:

ENTER BLUE BOOK DESC DATA SET INPUT FILENAME - A:C9DES

Then when prompted by the line:

"SAVE OBSDES PROGRAM OUTPUT TO A FILE (Y/N) ? "

Respond accordingly.  If the response is "NO", the output will be listed
on the screen and simultaneously printed (if a hard copy was requested).
If the response is "YES", then the following prompt will appear:

"ENTER PROGRAM OUTPUT FILENAME - "

Type in the filename of the program output (include disk drive
designation if it is not on the hard disk).  Example:

ENTER PROGRAM OUTPUT FILENAME - A:C9OUT

The program output will then exist on that specified file.  If you
want to look at the output go into the file via your editor and scan
through it.
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II. PROGRAMMER DOCUMENTATION - for program updating

    OBSDES follows the YOURDON style design that can be found in the Special
Projects Section of the Horizontal Network Branch, N/CG123.  The numerical
bubble designation of the design are indicated on the source code.  The source
code is in FORTRAN 77, ANSI Standard language.

    A. PC version -

    There is one file required for running OBSDES:  OBSDES.EXE

The disposition of this file is the responsibility of the Horizontal Network
Branch's software librarian currently (09/86) in the Special Projects Section
N/CG123.

    OBSDES.EXE - is created by linking with the Profort linker four object
modules which may in turn be created with either the Profort or RMfort
compilers from four modules of source code.  They are:

    OBSDES.FOR contains the following functions and subroutines:
    OBSDES,FUNCTION RESPON,HEAD,LINE

    OBSDBLK.FOR contains the following block data:
    BLOCK DATA

    OBSDSUB1.FOR contains the following subroutines:
    CHKDC,TWENTY,THIRTY,FIFTY,EIGHT0,EIGHT1,EIGHT2,EIGHT3

    OBSDSUB3.FOR contains the following subroutines and functions:
    BBDESC,MCH10,FUNCTION MCHSSN,MCH14,MCH30,MCHL30,FUNCTION MCHNAM,
    FUNCTION LOCNAM,ML30DS,FUNCTION MCHDIS,CKFLG1,MCHS30,MS30DS,MS30DR,
    REF1ST,CKFLG2,REF2ND,FUNCTION LM30DR,LM20DR,FUNCTION LM201,
    FUNCTION LM202,FUNCTION LM203,FUNCTION LM204,OBFLAG,FUNCTION MCHFLAG,
    OBFLG,OBFL80,OBFL81,LSTM,LSTMD,LSTD
