                  Micro World Data Bank in Polygons (MWDB-POLY)

                                INTRODUCTION
                                ============

         The full WDB-II is a digitial map data base produced by the
     Central Intelligence Agency (CIA) and distributed by the National
     Technical Information Service (NTIS), U.S.  Department of Commerce,
     5285 Port Royal Road, Springfield, VA, 22161.  Micro WDB-POLY is a
     highly compressed version which is suitable for use on micro computers
     and was put in this configuration by Micro Doc as Micro WDB-II.  Global
     Associates, Ltd added new data (primarily from Charles Culberson),
     made various fixes to Micro WDB-II, and rearranged the data into
     closed polygons.  Before describing Micro WDB-POLY a few words should
     be said about the source file - WDB-II.  The following paragraphs are
     paraphrased from the NTIS overview of WDB-II.

            WDB-II is a digitial representation of the world
        coastlines and boundries suitable for use in automated mapping
        systems.  It contains approximately six million discrete
        geographic points and was digitized using all available sources
        of information.  Map scales used range from 1:750,000 to
        1:4,000,000 with a nominal scale of 1:3,000,000.  These points
        are grouped by and identified as describing (1) coast lines,
        (2) country boundries, (3) state boundries (USA only), (4)
        islands, (5) lakes, and (6) rivers.  Each of these groupings is
        further broken down into features and subordinate classifications/
        ranks.  These ranks are hierarchically structured, and are also
        used for plotting symbol definition.

            WDB-II, as provided by NTIS, is in a 20 character format
        on five 9 track EBCDIC one-half inch magnetic tapes.  This data
        base consists of two types of records, one for the line segment
        identifier data, and the other for the latitude and longitude
        values of each discrete point making up the line segment.  In
        this format latitude and longitude values are recorded only as
        integers in degrees, minutes, and seconds.  WDB-II is available
        for $660.00 (Order Number PB-271 874 SET/HBG).

         Clearly, WDB-II is an excellent data source when making large (4
     x 6 foot) plots on a mainframe or minicomputer.  It is, however,
     somewhat large (150 - 200 megabytes) for use on microcomputers.  Even
     on the larger commercial online graphics systems, many points have to
     be filtered out before generating displays.  For this reason many
     people have spent considerable time over the past to filter and
     compress this data into a form which could be used in desktop
     computers.  To these people we wish to express our appreciation -
     particularly Antonio Riveria who provided us with a copy of the
     latest download of the file.

         The WDB-II product from which MWDB-POLY is derived may no longer 
     be availiable.  The CIA has replaced WDB-II with a RELATIONAL version.
     
         Contact Micro DOC (listed near the end of this document) for more 
     information on the 1995 Relational WDB-II CD.


                              BACKGROUND
                              ==========

         The present version began as a three megabyte ASCII text file
     which contained some 318,568 points selected from all six of the line
     types described above.  This file was then converted into a sixteen
     bit integer format which reduced the size to just over one megabyte.
     The file was divided into six files - one for each of the six line
     types then the Internal Political Borders were broken down into 4 
     separate files.  The file was configured such that it could be readily 
     moved to most desk top microcomputers.  The following table provides a
     brief statistical overview of the six line types which are contained
     in the data base.


                      Micro WDB-POLY File Composition
                      ===============================
         
         -------------------------------------------------------
         Detail PCOAST  PBORDER  PUSA48 PCANPROV  PMEXICO  PAUST
         Level   .PNT    .PNT     .PNT    .PNT     .PNT    .PNT
         -------------------------------------------------------

           1     22917    49073   6624      4978      879   1975
           2     27775    56754   6383      5714      997   2350
           3      4314    10163   1478      1113      181    634
           4      3033     7237    917       778      113    419
           5       890     4019    740       418     1984    187
         
         Total   58929   127246  16142     13001     4154   5565
         Lines       8      175     52        12       36      7

         ---------------------------------------
         Detail  PISLAND  PLAKE   RIVER    Total
         Level    .PNT     .PNT   .PNT
         ---------------------------------------

           1      20309    4671   11146   122572
           2      24190    5758   13217   143138
           3       3832     791    1817    24323
           4       2970     581    1254    17302
           5       1618     617     760    11233
         
         Total    52919   12418   28194   318568
         Lines      364      73     196      923
         
         The above table shows the number of points which are in each
     file and for each level of detail.  It also shows the number of line
     segments in each file.

         Detail level 5 produces the least detailed graphics image.  The 
     points at each level of detail are additive to the points at all lower 
     levels.  For example, when using detail level 4 the points from both 
     levels 4 and 5 must be used/retrieved.  Therefore, if one were drawing 
     lake lines at detail level 4, a total of 1198 (581 + 617) points 
     would be processed.  These 1198 points will describe 73 polygons.
     
         Note that the same number of polygons exist at all levels
     of detail.  For example, regardless of which level of detail is
     selected, there will always be 73 polygons described by the lake
     data file.  

         Actual use of the data in these files has shown that most
     displays which cover a reasonably large area do not need all of the
     detail provided at level 1.  A large area would be a major portion of
     the U.S.  For large area plots level 3 or 4 is normally sufficient
     and greatly reduces the number of points which must be processed. 
    
                 
                 MICRO WDB-POLY FILE AND RECORD STRUCTURES
                 =========================================

         All Micro WDB-POLY files are sequential files composed of fixed
     length six byte records which can be accessed randomly.  Each record
     is composed of three 16-bit signed [short] integer fields which can
     be read by all microcomputer languages.  There are no record seperators
     used in these files.  The record layout is:

                       | Code | Latitude | Longitude |

         Within the Micro WDB-POLY files the records are stored as shown 
     below.  In some cases there may be hundreds of points in a single line
     segment.  In other cases there may be consecutive header records
     which locate individual points to be plotted.

     |Header|Point1|Point2|PointN|Header|Point1|Point2|PointN|Header
     |Point1|Point2|Header|Header|Header|Point1|Point2|PointN|


         The same format is used for both the line header records and
     point records.  The usage of each field is as follows:


                              FIELD DEFINITIONS
                              =================

     CODE - Line Header Records.

     The CODE field is used to:

        1.  Identify the type of line segment which is described by
            the point records which follow it,

        2.  Identify the line or point within the line type, and

        3.  Provide the coordinates if the record describes a point.

         In header records the CODE field is always a positive four digit
     number in the form of: ABBB where

           A =                             BBB =          CODE =
            1 = Coast lines                 001 -> 008     1001 -> 1008
            2 = International Borders       001 -> 175     2001 -> 2175
            4 = Internal Political Borders (001 -> 107     4001 -> 4107)
                  U.S.                      001 -> 052     4001 -> 4052
                  Canada                    053 -> 064     4053 -> 4064
                  Mexico                    065 -> 100     4065 -> 4100
                  Australia                 101 -> 107     4101 -> 4107
            5 = Islands                     001 -> 364     5001 -> 5364
            6 = Lakes                       001 -> 073     6001 -> 6073
            7 = Rivers                      001 -> 196     7001 -> 7196

     CODE - Point records.

         In point records the CODE field contains the detail level.  The
     detail level is a value in the range of 1 through 5.  To properly
     retrieve points at any detail level use the following comparison:

        IF CODE >= DESIRED_DETAIL_LEVEL THEN ...


     LATITUDE and LONGITUDE - In both header and point records.

         The latitude and longitude fields contain the coordinate values
     expressed in signed minutes.  The values in these fields are computed
     with the formula COORD_VALUE = (Degrees * 60) + Minutes.  Thus, the
     ranges of coordinate values in MWDB-POLY are:

      90 00N =    5400
      90 00S =   -5400
     180 00E =   10800
     180 00W =  -10800

     NOTE: The Latitude and Longitude data can be converted on the fly to
     Decimal Degrees by dividing the signed minutes values by 60.

         MWDB-POLY uses the standard four quadrant cartesian coordinate
     system in which north, south, east, and west are referenced to the
     equator and the Greenwich meridian.

         When a header record is followed by point records the
     coordinates in the header record are the beginning of the line.  When
     a header record is followed by another header record then the
     coordinates in the header record should be plotted as a single point.
     When working at low levels of detail it is common to find multiple
     consecutive header records which locate isolated points.
     
         This documentation and the associated files are placed in the
     public domain and may incorporated into other products without fee so
     long as appropriate credits are included.  An appropriate credit line
     would be - "This product contains/uses data originally placed in the
     public domain by Fred Pospeschil and Antonio Riveria that has been
     modified by Paul Anderson of Global Associates, Ltd. The Original
     coordinate data was created by the Central Intelligence Agency."

                            
                            MWDBPOLY.ZIP CONTENTS
                            =====================

         MWDBPOLY.ZIP contains a MWDBII database that is reasonably up to 
     date, clean, and modified to provide closed polygons without using an 
     index file (Index files ARE available).

     The following files are in MWDBPOLY.ZIP:

     GLOBAL.TXT   - About Global Associates, Ltd.
     GOODEIHS.BAS - Quick Basic program that draws Goode's Homolosine 
                     projection interrupted for continental unities.  The 
                     Plot file routines and the way the map is drawn inside 
                     the "extensions" are NOT the best, but it works. The 
                     plot files import into Corel Draw with no problems. 
                     
                     NOTE: The Open file statements will have to be modified 
                     to reflect where the *.PNT files are located on your 
                     system. This program was written for Quick Basic 4.5,
                     however, it will run (slowly) with the Qbasic interpreter 
                     that comes with MSDOS.
     MWDBPOLY.TXT - This document.
     PBORDER.TXT  - Notes on PBORDER.PNT and VECTOR graphics output.
     PCOAST.PNT   - Use this file when you don't want Political Borders.
     PBORDER.PNT  - Use this file in place of PCoast.pnt when you want 
                     political borders.
     PUSA48.PNT   - USA internal Political Borders.
     PCANPROV.PNT - Canadian Internal political Borders.
     PNTCONV.ZIP  - Two programs that can be used to convert the *.PNT files 
                     to and from ASCII.
     PMEXICO.PNT  - Mexican Internal Political Borders
     PAUST.PNT    - Australian Internal Political Borders.
     PISLAND.PNT  - Islands of the world.
     PLAKE.PNT    - Lakes of the world.
     RIVER.PNT    - Rivers of the world. Original MWDB II file (No Polygons).
     SELECT.EXE   - This program is from the original MWDB II distribution 
                     disks. You can use it to: 
                
                     1) Combine all the *.pnt files into 1 (one) file.
                                           Or
                     2) Create *.PNT/*.MAP/*.ALL or *.CCI files containing 
                         less data.
         
     ------------------------------------------------------------------------
     MWDB-POLY can be used AS IS with the following programs:           
     
       1) Charles Culberson's VersaMAP (70511.3134@compuserve.com)
       2) Philip Voxland's WORLD (voxland@atlas.socsci.umn.edu)
       3) Daan Strebe's GeoCART [MAC] http://terradata.com/
       4) Scott Loomer's MicroCAM and WinCAM
          ftp://ftp.usma.edu/g&ene/gsl/microcam/          
          - or -
          http://wolf.its.ilstu.edu/microcam/

     ------------------------------------------------------------------------
                            
                            
                              FINAL NOTES
                              ===========

         This document is a modified version of the original that is included
     with the Micro WDB-II database.
     
     Additional map data base products may be obtained from:

      Fred Pospeschil (AKA Micro Doc)
      2739 42nd St.
      Two Rivers, WI 54241-1111 

      E-mail: fwp@excel.net 

      - and -

      Charles Culberson
      8 Ritter Lane
      Newark, DE  19711

     The MWDB-POLY database is released to the Public Domain by: 

      Global Associates, Ltd.
      Suite 206
      1206 Laskin Road
      Virginia Beach, Va.

      Ph. (804) 428-4902
     
     =====================================================================    
         ALL USERS OF THESE MATERIALS ARE TOTALLY RESPONSIBLE FOR THEIR
     USE AS THESE MATERIALS ARE PROVIDED WITHOUT EITHER EXPRESS OR IMPLIED
     WARRANTIES OF ANY KIND.
     =====================================================================
