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[aprssig] California APRS Mile Marks

Robert Bruninga bruninga at usna.edu
Sun Apr 10 15:54:50 UTC 2005


Many new-generation APRS users may not be aware
of how APRS includes Interstate Mile Marks so that you
can quicly and easily put a non-APRS mobile on the map
who reports his traveling position by "mile mark".  This 
has been in APRS since the mid 1990's, but most people
are not aware of it or dont use it.

In APRSdos, just hit MM and then the State and Interestate 
number.  For example MM GA95 will plot the milemarkers in
Georgia along Interstate I-95.     This capability is also in 
UIview under PMapserver-7 select MAP-SEARCH.

But the file we use does not have any data for California
beacuse only recently did California begin to at least number
all of its exits by mile-number.  So we need a volunteer to
build the California entires for the mile-marker file from the
data on the California WEB page shown in the following
email that is circulating on the UIVIEW list.

The original MileMarks system from APRSdos and what
was inplemented in UIview uses the data file MILEMARK.DAT
and is described in:

 http://www.ew.usna.edu/~bruninga/APRS-docs/MILEMARKold.TXT

The APRSdos national mile-mark data file was upgraded
and improved as MM-DATA.DAT in 2003 and is
described in a newer text file as:

http://www.ew.usna.edu/~bruninga/APRS-docs/MILEMARKold.TXT 

This newer format is much more user friendly because it contains
LAT and LONG for the key mile marks instead of just one or the
other for the original N/S or E/W format.

I hope a volunteer will come forward to take the
data off the WEB page below and masage it into
the needed MILEMARK.DAT or MM-DATA.DAT
file..... thanks       Bob

*-------------------------
This is brought over from the UIVIEW list

>>> bruninga at usna.edu 4/10/05 10:58:46 AM >>>

>>> ve7gdh at rac.ca 4/9/05 8:55:00 AM >>>
>>Chuck provided a link to the Calif Interstate Exit numbering system:
>> http://www.dot.ca.gov/hq/traffops/signtech/calnexus/ 
Keith said:
>The info listed ... would make it super-easy to create a few 
>entries for the milemark.dat file. Anyone going to ... do it? 
>Even [without] "mile markers" on the side of the road, 
>knowing that the exits are numbered ...on mileage ...
>would still make them useful.

Yes someone please do and dont just list every single exit.
List only those that mark a change in the road from a straigh
line segment.  If the exit is not at a bend, you can still use
the exit number to estimate the actual mileage of the bend
in the road, and it is only the Bends that are needed in this 
file.  If anyone takes on this project, please make sure I get
a copy...

These positions do not need to be exact, just approximate
to say a fraction of a mile...

thanks, and we can move this discussion off list...

Bob, WB4APR







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