***Green Ball*** APRS is an amateur radio system to send/receive GPS position data. It can be used to keep track of mobile and fixed resources, weather reports, hurricanes, trouble area, etc. I'm working to integrate it into the local search and rescue organization. Many areas are integrating it into their local EOC offices. Here's a link to my Turnkey APRS Web Pages oriented towards SAR and APRS, and here's another more general APRS link to get you started. Software is available for DOS, Mac, Win32, Linux, Solaris, FreeBSD, PalmOS, WinCE, and probably others. Here are a good set of APRS tutorials written by Arte Booten, n2zrc.

***Green Ball*** The Xastir APRS program now has support for geoTIFF image files, including USGS DRG topo maps. It'll tile together a seamless topo map from multiple 7.5' topo maps and plot APRS objects and tracks on top of them. Check out the latest CVS snapshot to get this capability. It should appear in the next public release of Xastir as well. Here's the Xastir Home Page. . Xastir includes support for local Linux AX25 devices, can connect to remote aprs servers, and can connect to remote GPS data via the GPSD daemon. You can even automate saving screenshots to JPEG files to be read by web browsers. Did I mention that Xastir is free, including sources, and runs on Linux, Solaris, Mac OS X and FreeBSD? Sorry, we don't do Windows. Not directly anyway, but there are ways to run it on there. Xastir Major Features.

***Green Ball*** Free UTM Tools . These are useful for translating to/from paper maps. It's much easier to get a more accurate position plotted using these tools.

***Green Ball*** Here's a site where you can get USGS DRG topo maps as well as other types of maps: GIS Data Depot . Unfortunately only some of their data is free now.

***Green Ball*** A new vendor of topo maps that looks interesting: Igage.com .

***Green Ball*** Interested in digital maps? Get MicroDEM from Peter Guth's Web Site , which handles USGS DEM/DLG, Tiger, and Satellite image files. This program allows you to draw color topo maps or 3-D surface maps, which can be overlaid on top of satellite images. It can also overlay roads and waterways on top of the maps. Win32 program. Snag the example files as well to try it out, then go to the USGS site and get the DEM and DLG files for the areas of interest.

***Green Ball*** For a site that will show you topo's online, check here: TopoZone.com .

ArcExplorer is a free package that can be used to view USGS DRG files.

Other good programs for use with DRG's are OziExplorer and Fugawi (see my GPS page, last section). SARMAP, for Search & Rescue personnel gives the capability to draw topographic maps with roads/water overlays on a Windows PC. It uses the USGS DEM/DLG files also. Go to "programs/sarmap" directory. It is getting a bit dated though. I've also noticed that DLG and DEM files are not quite aligned properly. Nice program overall though.

Check out DLGV32 for a Win32 viewer for DLG-O and DRG files (free from the USGS).

Go to the US Geological Survey to get DEM or DLG digital map files for any place in the U.S. They have more detailed DLG files available now than the 1:100 scale ones. A few map files may also be found at the Xerox FTP Site . Here are the USGS Home Page , and the USGS Data Products Page .

Elgaard Positioning System . This is Java software which is GPL'ed (free including sources), which runs inside a browser (Internet Explorer/Netscape) or within the Java JDK. If using Linux, the program can directly communicate with a GPS using the GPSTRANS program (See Peter Bennett's Site on my GPS page). Scanned maps just have to be rectangles in GIF or JPG format, but can be any size/scale.

Digitized 7.5 minute USGS topo maps are now available on CD-ROM. They are in the neighborhood of $32 (US) per CD-ROM, and each one contains 1 degree by 1 degree of maps, which equates to approximately 64 maps on a disk. They are stored in large TIFF files.

Another good mapping program to check out is GPSS, which will allow your GPS equipped laptop to have moving map capability. If you have a sound card in it, it can speak to you to tell you your location. Uses BMP maps and WAV sound files (yes, you can add maps and sounds to it). Here are some other sites from which to get GPSS: ehssun1.lbl.gov , and ourworld.compuserve.com . Click here for more map links.

***Yellow Ball*** Make sure to check out my GPS Page for many more map links.