[mapserver-users] upload/stream data from GPS unit?

Brent Fraser bfraser at geoanalytic.com
Thu Mar 27 11:46:25 PDT 2008


Bill,

  Maybe.  It depends what your expectations are with respect
to Near-Real-Time.  Mapserver can support GDAL/OGR layers if
Mapserver is built with GDAL+Expat (not uncommon, but my
version isn't built with Expat).  I think the layer
definition might look something like:

LAYER
    NAME "gps"
    TYPE point
    STATUS DEFAULT
    CONNECTIONTYPE OGR
    CONNECTION "mygps.gpx"
    CLASS
        STYLE
            COLOR 0 0 255
        END
    END
END

Hopefully (!) there won't be any file access problems if
your GPS s/w is creating the gpx file the same time
Mapserver/GDAL is trying to read it.

We implemented a tracking system a few years ago by writing
a program to insert/update positions (received every 30
minutes per gps unit by email) into a PostgreSQL database
and have Mapserver read the positions from there.  Using a
relational database avoids the file locking problem and
provided a few other benefits.

Another limitation of Mapserver is the fact that is doesn't
push any data to the end application (e.g. browser, WMS/WFS
client) until it is requested.  For example if you show a
raster map in a browser and don't refresh it for an hour,
your positions as displayed in the browser are an hour old.
Of course it is possible to code some html/javascript to
request a new map every so often.

If your main interest is in how to get the positions from
the GPS receivers into a database, as far as I know there
are no open standards used directly by the GPS vendors.  One
open project is http://www.opendmtp.org/.  Another effort is
the Ham radio APRS (while the radio part is for
non-commercial use only, you might be able to use some the
ideas in the upper levels of the protocol). In any case,
you'll likely need to do some programming/scripting...

Brent Fraser
GeoAnalytic Inc.
Calgary, Alberta

----- Original Message ----- 
From: "Bill Wordsworth" <bill.wordsworth at gmail.com>
To: <mapserver-users at lists.osgeo.org>
Sent: Thursday, March 27, 2008 11:52 AM
Subject: Re: [mapserver-users] upload/stream data from GPS
unit?


> Please let's not hijack my poor thread :)! Anyway, here's
my original
> question:
>
> "How can I upload/stream near-real-time GPS data from
on-site to
> webserver/MapServer (MapServer 5.x can read *.gpx)?"
>
> I've been referred to http://franson.com/gpsgate/ from the
usenet groups. I
> am looking for something with WPA.
> Cheers, Bill
> On Wed, Mar 26, 2008 at 11:39 AM, Carlos Pinto
<cmspinto at gmail.com> wrote:
>
> >
> > Hi all,
> >
> > I'm new in MapServer and I'm using Openlayers that can
be a client of
> > MapServer.
> >
> > What I'm trying to set-up is a grid that is in GML file.
And I want
> > MapServer to build the layer reading the GML file and
give it to OpenLayers
> > (javascript API) would read it as WMS.
> >
> > I have instaled MapServer in C#  so I'm using MapScript.
Is this possible?
> >
> > Thanks
> >
> > Carlos
> >
> > _______________________________________________
> > mapserver-users mailing list
> > mapserver-users at lists.osgeo.org
> > http://lists.osgeo.org/mailman/listinfo/mapserver-users
>
>
>  On Wed, Mar 26, 2008 at 11:25 AM, Bill Wordsworth <
> bill.wordsworth at gmail.com> wrote:
>
> >  How can I upload/stream near-real-time GPS data from
on-site to
> > webserver/MapServer (MapServer 5.x can read *.gpx)?
> > Cheers, Bill
> >
>


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