README.100   (as of 2/13/94)

                   1:100,000 CD ROM Map Making

                         W7KKE  
                         Ken Swaggart  
               w7kke @ ka6eyh.#nocal.ca.usa

The 1:100,000 line segment maps contained on the USGS CD ROM uses
a different format than the 1:2,000,000 CD ROM maps. My first
utility, CONV100.BAS, converts the 1:100,000 map "Optional Format" 
extracted files to the .GRF file format which can be read by the APRS
MAPFIX.BAS program. When you import these map files into MAPFIX you
will notice they are extremely fragmented into small line segments
which are not adjacent. The second utility, DEFRAG.BAS takes the saved 
MAPFIX file and defragments it.

Corrections made since the September first "pre-beta test" version
are:

  a. Fixed the DEFRAG.BAS so it doesn't eat color/attribute lines.

  b. Corrected endless loop problem in DEFRAG.BAS so that it saves
the file and exits when it detects that no corrections have been
made during the previous pass.

  c. Enhanced CONV100.BAS so that the road type and number is added
to the attribute line, i.e. US101, I-5, etc.  No road info will
show up for anything below county roads. This is handy for manually
editing the map.

  d. Incorporated WB4APRs enhancements from his MY100.BAS. The
program now extracts all the roads by looping through the
extraction routine.

  e. Added code in CONV100.BAS to adjust the converted latitude and
longitudes due to rotation of UTM grid from due north.

  f. Was missing large rivers, so now extract "near shore" and "far shore"
water body segments.


Here are the step by step instructions:

  1. Create a directory on your hard drive where you will be work
on your maps. Stick my programs in this directory and copy
MAPFIX.BAS from the APRS directory into this working map directory.
I use C:\APRSMAPS as my working map directory.

  2. Extract "Transportation" and "Hydrography"  for your area of
interest from the 1:100,000 CD ROM using the extraction program
which comes on the CD ROM. I zoom down to the 15' scale on the USGS
extraction program before I extract the map file. Copy these files
into your working map directory.

  3. Run CONV100.BAS.  The program will extract each feature, such
as Interstates, US Highways, etc., as separate files with the
filename extension of .GRF. 

  4. Run MAPFIX.BAS. Import the first converted .GRF file  by using
the @U command in MAPFIX.BAS. After the file is imported you and on
your MAPFIX screen use the Join command (@J) to join adjacent line
segments for this feature. Save this feature as its own .MAP file
and repeat the process for each map feature you created. 

  NOTE: Make sure you use the same origin and scale each time you
        import the .GRF file using the @U command.

  5. Run DEFRAG.BAS to de-fragment the .MAP files you have created.

     If DEFRAG.BAS crashes, you can recover most of your defragmented
     segments. Look for SCRATCH1.TMP and SCRATCH2.TMP. Rename the
     larger of these two and delete the remaining .TMP file.

  6. Use a text editor, such as DOS's EDIT, and examine your
defragmented .MAP files and tweak as you see fit. You may find that
some line segments consist of only one point - edit those out.

  7. Run MAPFIX.BAS again and import your defragmented .MAP file.
Check it over for any obvious errors, correct those, then run the
smoother function (@SMOOTH) to pare down the .MAP file.

  Note: I generally do not run smoother on the water boundaries and
streams, but hand edit to reduce the points. Another option which
works well is to use the U command to overlay the water boundaries
and streams, then manually draw in the rivers with the @new and @A
commands. This results if far fewer points than the automatic
method.

 8. Save your smoothed .MAP file and import your next feature and
repeat the process. (I only run the smoother on each separate
feature file so I can control what gets smoothed.) Sometimes I have
to bump the smoother factor way up to pare down the points to fit
the total point limit for APRS.

  9. Use a text editor, such as DOS's EDIT, to assemble the final
map from all the defragmented and smoothed .MAP files created for
each map feature type. 

  10. Run MAPFIX again and import the resulting complete .MAP file
with all your features. If it is too large, which it probably is,
delete points until you have a map which will fit within APRS
limits. 

  - There is some small errors (less than 1/4 mile) toward the north east 
and north west sections of the map. This is due to the conversion scheme 
I use to get from the UTM grid to lat/long. The two grids do not line up
exactly. When you join two adjacent 15' maps, you will see that the roads 
are off by about 100 meters. Use mapfix to tweak the lines so they join.


Please send me any program enhancements/fixes you make to either
program. I'm sure there are a lot better ways to defragment the
.MAP files - there MUST be!

PS - watch out for "Streams" - when I extract the ones around here
the resulting .MAP has thousands of points! 

