CONTENTS: APRSdos STREET LEVEL MAPS OF ONE OF THE FOLLOWING COUNTIES OF NE FLORIDA:
fl??map#.zip - ?? County, FL, where ?? is one of:
FILE COUNTY NUNBER OF FILES FOR COMPLETE MAPSET
fldu - Duval County, FL Two files fldu1 and fldu2
flcl - Clay County, FL Two files flcl1 and flcl2
flsj - St. Johns County, FL One file flsj
flna - Nassau County, FL Two files flna1 and flna2
flpu - Putnam County, FL Two files flpu1 and flpu2
flba - Baker County, FL One file flba1
flbr - Bradford County, FL Two files flbr1 and flbr2
PLEASE NOTE: These APRSdos maps were produced as a public service for Amateur Radio use and Emergency Preparedness by NOFARS, The North Florida Amateur Radio Society. These maps provide street level coverage of all seven counties (Baker, Bradford, Clay, Duval {Jacksonville}, Nassau, Putnam, and St. Johns) of the Florida Crown District. These maps may be distributed without charge so long as credit is given to NOFARS for their funding and Alan Crosswell, N2YGK, as the author.
README -- Documentation for the local area APRS map maintainer.
See also, INTRO, a short introduction to using these maps.
APRSdos detailed street maps from US Census TIGER/Line 1995 files.
Generated by Alan Crosswell, N2YGK, n2ygk@weca.org using tig2aprs.
If you would like maps like these for another county, please contact
me for more info.
The zip files
-------------
The distribution is in a bunch of zip files meant to be unzipped
relative to the APRS main directory.
fl??map#.zip - ?? County, FL, where ?? is one of:
du - Duval County, FL
cl - Clay County, FL
sj - St. Johns County, FL
na - Nassau County, FL
pu - Putnam County, FL
ba - Baker County, FL
br - Bradford County, FL
and # is 1 or 2 (the files are split up to fit on floppies).
The zips are in 1.44MB chunks so they can fit on a 3.5" floppy.
Within each zip file are the following subdirectories:
maps - contains the map files
maplists - contains the maplist files
tig2aprs - miscellaneous junk that you can unzip and look at
but not necessary for use with APRSdos.
To get setup on APRSdos, CD to the APRS directory and UNZIP each of
the files. For example, for Duval:
Assumes you have PKUNZIP or similar file decompressionprogram and know how to use it, if not
refer to that untility program's instructions:
cd \aprs
unzip a:fldumap1.zip maps/* maplists/*
unzip a:fldumap1.zip maps/* maplists/*
More details about the contents of the subdirectories follows:
MAPS - APRSdos map files
-------------------------
Maps rendered at ranges of 16,8,4,1 miles plus one big APRSdos map.
Naming scheme is:
fl??h000.map - 32 mile map radius (one map)
fl??g000.map - 16 mile map radius (one map)
fl??8###.map - 8 mile map radius (several maps)
fl??4###.map - 4 mile map radius (several maps)
fl??1###.map - 1 mile map radius (hundreds of maps)
?? is one of du,cl,sj,na
### is a 3-digit automatically generated (meaningless:-) map number
MAPLISTS - Maplist files
------------------------
maplist.du? - a set of maplists for Duval County
maplist.cl? and so on for Clay,
maplist.sj? St. Johns, and
maplist.na? Nassau
Where ? is one of blank,A,1,2,3,4
maplist.xxA - All maps. This maplist is too large to actually use
with DOS aprs which has a 169 maps per maplist limit
and is meant solely as a reference for you to cut and
paste your own maplists together from. In fact, it is
not even a true maplist since it is missing the header
lines.
maplist.xx - All maps with no overlaps. This gives you full coverage
but you have to HOME at the crosshair to see each map.
Panning (tracking, etc.) off the crosshair will cause
APRSdos to back off to the next larger (less detailed)
size.
maplist.xx? - Where ? is one of 1,2,3,4 for the NW,NE,SE,SW quadrants.
Full coverage (maps plus 3 overlays for each). This
maintains the same level of detail when panning across
maps zoomed in at 1/2 the map scale. For example, at
the 1/2 mile scale, you can pan relatively smoothly
across the screen as APRSdos automatically loads the
next map that fully encloses the viewing area. Due to
maplist size limits, all detail maps cannot fit in a
single county-wide mapllist.
Each maplist starts with what was in MAPLIST.FL2 which is a Florida statewide
maplist found in:
ftp://ftp.tapr.org/tapr/SIG/aprssig/files/maps/PCMaps/flmaps02.zip
You also may want to acquire the following maps if you don't already have them:
ftp://ftp.tapr.org/tapr/SIG/aprssig/files/dosstuff/APRSdos/semaps12.zip
ftp://ftp.tapr.org/tapr/SIG/aprssig/files/dosstuff/APRSdos/emaps13.zip
TIG2APRS - Other files
----------------------
The following files are in the tig2aprs directory:
log.??# Execution log from tig2aprs showing what it did.
?? = county, # = range (h,g,8,4,1,w)
maplist.xxa The reference list of all APRSdos maps supplied. Use
as a source of mapnames when customizing your own
maplists.
Maplist details
---------------
Each maplist file line is commented with details that will help you
manipulate the maps. Except for the root map, each maplist
entry is either a quadrant of a parent map which was tiled because it
had too many datapoints, or an overlap of a base map. You can toss
all the overlaps for example and still have full coverage; just not
smooth panning.
Comment examples:
..., NW quadrant of fldu8000
..., E overlap of fldu1018
The map referenced for quadrants doesn't actually exist, since it was
split into 4, but you can see more about it in the log file.
Map details
-----------
Maps have been generated at several levels of detail, which for
lack of a better term, are designated by the map range in miles
for which they seemed to fit. The levels are:
>16 - Major features only such as interstate highways, oceans, large rivers.
8 - Adds major highways.
4 - Adds minor highways.
1 - Full street detail
Since APRSdos limits a given map file to 3000 data points, it is impractical
to have a reasonable looking map with full detail at any greater than a 1
mile range. In certain dense urban areas the best one gets is a .5 mile
map range. You will see some of these near the center of Jacksonville.
If you actually read a map file in a text editor, you will see a few
items worth noting:
In the comment block you'll see something like this:
Map generated by tig2aprs from 1994 US Census TIGER/Line.
tig2aprs (c) 1996,1997 Alan Crosswell N2YGK
map has 2965 points f=20 wf=0.107 sf=0.165
The third line shows the number of data points, how badly "fuzzed" the
map was (how far apart two data points can be and still be considered
the same. f=20 is the worst I will settle for); what percent size a
water body had to be to not be filtered out of the map (small lakes
that cover less than 10.7% of the map area were tossed); and a factor
that I can't explain to myself even that shows how close the slopes of
two line segments have to be in order to be collapsed into one (saving
a data point).
Each map feature is commented with details as well. For example:
3 ,(H11)Alligator Creek 84106848
This is an APRS color "3" (blue; see README\MAPMAKIN.TXT) feature.
The Census Feature Class Code is H11 (perennial stream or river),
"Alligator Creek" is the name (according to the Census records) and
the 84106848 is the unique TIGER/Line ID (TLID) of the feature (or one
of the features when they get chained together). Note that similar
features that are end-to-end are glued together to save data points,
so the TLID is only for one end of the chain. There are probably
20 or more TLIDs associated with the feature.
There are also a bunch of labels at the end of some map files which
correspond to names of places that come from the TIGER/Line data.
Appropriate APRS special symbols are included. You will frequently
find 2 or 3 words stacked one above the other. This is because APRSdos
is restricted to a 12 character label, so longer multi-word names get
split up by tig2aprs.
$/ENassau,30.538187,81.819466,4.0
Village,30.537394,81.819466,4.0
Ratliff,30.536601,81.819466,4.0
Jones,30.561619,81.860252,2.0
Cemetery,30.560826,81.860252,2.0
The labels come from the US Census concepts of places, key geographic
locations, and point and area landmarks.
More info
---------
Source code and documentation for the free program that generates
these maps is available at http://www.cloud9.net/~alan/ham/aprs.
Information about the US Census TIGER/Line data can be found at
http://tiger.census.gov.