A Better Breed of GPS Software?
willo asks: "I recently built an on board computer for my Grand Cherokee.
The initial uses for it include music, gps navigation, on board diagnostics and a baby cam so I can see how my kid is in that rear facing seat. After lots of research and testing, I'm really disappointed with the
mapping software out there for Linux. Gpsdrive provides the basic functionality I need, but the street names are built into the image and
are difficult to read at a glance while driving. Not to mention that it has to download the maps it needs ahead of time. Xastir can handle almost any map out there, but it reads through every map for each redraw! It also seems to lack the ability to zoom intelligently based on location. Note that it's not really designed to be a navigation aid, but rather a ham radio APRS tool. (I am a ham). Delorme Street Atlas USA does what I really want, but it's been a pain to make run properly under wine. Is anyone else out there working on a decent navigation application?"
Map Sources do exist for this! Bruce Perens made TIGER/line data availible. NAVTECH is the map source for pretty much all the vehicle navigation systems out there, and high resolution maps are availible from the Geographical Information Survey."
"To be really usable navigation software should do the following:
- handle maps efficiently and draw them quickly
- have intelligently organized map sets for countries/states. (You can't download a friggin map in the middle of Montana!)
- include serial gps/gpsd support. (just about everyone has this)
Map Sources do exist for this! Bruce Perens made TIGER/line data availible. NAVTECH is the map source for pretty much all the vehicle navigation systems out there, and high resolution maps are availible from the Geographical Information Survey."
...if you can code in Java, my open source GPS library will make this a much easier process. Demo applications are included (for PC's and Palm's).
.pdf format). I built some mapping/tracking display software (based on the GPS Library) that is used as part of this project.
All at Chaeron GPS Software
Also check out the Mobile GPS Demonstration Platform (MGDP) project info (in
Enjoy!
Chaeron Corporation
I write GPS mapping software for Windows, aimed at the outdoor recreation market. You can check it out at http://www.expertgps.com/
ExpertGPS is unique in that it pulls down topo maps and aerial photos over your Internet connection, so you can scroll the map across the country and the program automatically downloads and displays the correct maps. For the geocachers out there, ExpertGPS reads geocache data downloaded from http://www.geocaching.com/, and even links back to the geocaching website to report your finds.
The next release will support scanned paper maps and additional file formats, and a PocketPC version is in the works.
About a year ago, a bunch of GPS developers got together to work on a standard XML file format for exchanging GPS data. A number of programs now support GPX (the GPS Exchange format), including programs for Mac, Windows, and Linux. For details, see http://www.topografix.com/gpx_resources.asp
I'll probably get bashed for this, but here goes. When shopping for a computer, find the killer gotta have program and purchase whatever hardware is needed to run it. For Web servers, that is Apache. For in vehicle nav and Ham Radio, (especialy moving ADF work) the aps are mostly Windows. :-(
Now on to the informative stuff... There are two kinds of maps. Vector and Raster. Vector maps are smaller. The text and roads are just data, so road names can remain the same size at various zoom levels. Raster Maps are photos of maps. These are great for off road treks as they are detailed. The road names can be hard to read on vector maps. I use both kinds of maps. (I'm also a dedicated geocacher). I use the National Geographic TOPO maps with the GPS most of the time (great detail helps find best route to difficult location) TOPO maps are about 6 CD's per state for about $100 per state. They have full GPS waypoint management ability. Building a route is as simple as dropping waypoints on the map, connecting the dots and uploading it to your GPS. The other software I like for highway cruising is Streetfinder. It does not have upload/download abilities, but it does do a great job showing where you are. You can record your adventure and play it back later. Use it to fight that radar ticker. It plays back just like a saved race game including the time, speed and location. It makes a great package to check on your teen's driving. Find out where and when they went after or during the prom! The Vector software was much cheaper at $17 for the entire US on 3 CD's and included 1 CD of trip planning software. I have found no Linux replacements for either package. Since one of my older laptops came with Windows 95, it has become the mobile map unit. Hackability of the OS is of no concern, it has no net connectivity, so the security holes are not important for this application. No Office, No VBS, No TCP/IP, No hackers.
I forgot the name of the package, but there is a nice APRS feature being built into one of the map packages that supports RDF showing not only your location but the direction of your DF target. Great for getting a running fix on a fox if you also have auto DF with RS232 output. A Google search should show the DF version of APRS. It only works with a static map so far. Moving maps are not yet supported.
The truth shall set you free!
More intelligent map handling is in the works for Xastir. For things like Tiger maps it already doesn't read thru every map for each redraw and the maps are nicely detailed. And organizing the tigermap sets is high on the list of todo's.
If you see features that are needed, come on by the sourceforge project page at http://sourceforge.net/projects/xastir/ and leave a feature request. Or join us on the mailing lists at: http://krypton.hscs.virginia.edu/mailman/listinfo/ xastir-dev
and http://krypton.hscs.virginia.edu/mailman/listinfo/ xastir
The developers are active and very responsive to reasonable feature requests. (heck we even accept some of the unreasonable ones :-)
The OpenGIS Consortium is a standards body which has been thinking a lot about the technologies, protocols and infrastructure needed to support the kind of tasks you want to perform. (Acualy, so far a lot of it has been behind closed doors as the Open in OpenGIS tends to come into effect once they think they have the standards right)
You can find out a bit more about one initative that they are involved in here:
http://www.openls.org/about.htm
And a google on OpenLS will bring you back more.
Now, all that tells you is about the standards, but doesn't give you any tools you actualy need.
[big self plug]
I am one of the lead developers of GeoTools2 an open source Java project which is aiming to implement as many of the OGC standards as make sense (and those of other standards groups if they seem appropriate). So far the toolkit will give you the parts you need to read a number of datasources, filter them to show what you want to see and render them using a detailed styling descriptor aimed at geographic information.
It dosn't hook to GPS yet, though the ChaeronGPS library mentioned in other posts may merge well with what we have alrady.
I'm not a mobile map expert, though I would be happy to combine the map rendering expertese I have with someone who is activly developing GPS solutions.
GeoTools2 is available under the LGPL (www.geotools.org), the OGC can be found at www.opengis.org
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Spell checker (c) Creative Spelling inc. (aka my dyslexic brain)
Spell checker (c) creative spelling inc. (aka my dyslexic brain)
Advantages:
Although GRASS (GPL) is just now running on PC's via Cygwin, it was designed as a Unix GIS. What it provides:
* A framework for organizing, storing and retrieving maps.
* Map information that can be presented multiple layers at a time.
* A means of generating an image file based on various map layers.
* A map feature attribute mechanism. This is what allows you to control street names and how they appear as you zoom in and out.
* A C api with over 800 GIS functions. (Also a Java interface)
With GRASS, you could write a C program that monitors the GPS fix queries the map database and repeatadly presents the info as a image on your screen.
BTM
That was the turning point of my life--I went from negative zero to positive zero.