[Xastir] APRS with non APRS equiped stations ?

[Curt Mills]

On Wed, 15 Dec 2004, Wes Johnston wrote:

> Just thinking aloud.... if you were to have a text file that contained one line
> per 100 feet of $GPGGA data (or other lat/lon data), then your tracking program
> would would simply have to lookup the correct line inthe text file.  It is
> entirely possible to set a GPS to record points based on distance.  All the
> program needs to do (note how I say that as if I could actually write it!!) is
> calc distance traveled based on time and then divide by 100 feet, fetch that
> line from the file and display the object at that point.  Easy eh?

GPGGA or GPRMC or one of the other few that have position data in
them.  Yea, it would be VERY easy to make a Perl program that fed
lines into Xastir at a set rate.

I'd go one further and have one data file that defines all the
course points, another that defines the objects.  Keep track of a
pointer and a speed for each object.  Use that pointer to snag the
next line of NMEA for that object, create an APRS object or item
packet for it using that position, inject it into Xastir's server
port.  Sounds like something that could be written in an evening or
two, with probably only five years to adequately debug it.  ;-)


> Heck that would even work for laps around the same course.... just drive the
> course with your GPS ahead of time and transfer the bread crumb trail points to
> the text file.

Or have Xastir log it as you drive around.  Or use GPSMan to suck in
the track to create the file.  Or manually create it by dragging an
object around the map, clicking on every interesting point, then
saving the track for that object.  That last would currently create
a Shapefile though, which is probably not what we want in this case,
but that could be made to work as well.


> Something I do know how to write would be a program that would take arbitrary
> points from a GPS $GPxxx file, interpolate between the points and output the
> lat/lon of each 100 foot marker.  Then the recorded data density wouldn't
> matter... record at any time or distance interval and my program (which has not
> been written) would output a text file with markers every XX feet.

I think we're all sneaking around roughly the same idea.  Get this
hammered out a bit more as to the requirements and then see if you
can sucker someone into...er... convince someone to write it.

-- 
Curt, WE7U.				archer at eskimo dot com
http://www.eskimo.com/~archer
  Lotto:  A tax on people who are bad at math. - unknown
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