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I've replaced google earth with Xastir. Xastir is for ham radio station tracking but it featurs address lookup, multiple map layers, online maps, tigermaps, and gps support. When I was a cab driver I could use xastir to look up addresses offline because it's address mappings are stored locally. It doesn't look fancy, but it does look professional. http://www.xastir.org/

Though slightly off topic from image inversion I'll put in my 2 us cents.

As a HAM radio operator I use an "embedded" PC running Xastir in my vehicle to track my location, the location of other HAM operators, send brief text messages and for the reception of weather alerts. I find it VERY useful if I can locate an open access point which further allows me to download live weather radar images, check on forecasts, etc. While I realize the "theft" of their service is considered illegal by most I hope it would make some aware that if they own a wap, and the weather is severe but you're brave enough to leave your equipment on you might consider removing security from it, especially if you see a vehicle with lots of antennas roaming the neighborhood.

Now, please don't confuse the black excursion with loads of antennas for a HAM radio operator. That is likely the NSA or RIAA/MPAA looking for goodies. The HAM guy will be in a beat up 80's model vehicle and likely be short, fat, and pale, much like your typical WoW player, except older and more intelligent. (Just Kidding!!)

Anyhow, there are both positive and negative aspects to open WAPs, the best anyone can do is educate people about the consequences and once that happens, I guess us HAMs will have to go knocking on doors.

73s

• One, called PSK31, uses less bandwidth than a morse code signal (31Hz), and uses a computer soundcard to audio encoding and decoding. You can read more about it here. You can talk around the world with 5 Watts on HF (high frequency, 14.070 MHz, in this case). There are other, similar, digital modes available for keyboard-to-keyboard communications (synchronous, non face-to-face) that have different radio propagation and bandwidth characteristics, as well as image transmissions modes that work on HF, which propagates world-wide, and you can read about those in the PDF presentation above as well.
• The other, APRS , uses VHF and UFH (usually 144.39 MHz in the US), and because of the shorter range, uses a store-and-forward packet technology. This mechanism is more like SMS in that it is asynchronous, non-face-to-face, and in that it uses a network of repeaters and packet forwarding systems, and message lengths are limited.
  
  There used to be a wider ham packet network, back before the ARPANet became the Internet; this piggybacks on the technology and uses it for short message, position reporting, and weather reporting. Check out APRSWorld.net for open-source software for the network side of this. (The radio side is already taken care of in the Linux kernel, and in various Windows packages. There is also a client program called XASTIR.

Best. ham. radio. software. ever. I wish every application was so great.

http://www.xastir.org/

We sort of have something like that in the Xastir project.

It true purpose is a client for the APRS (Automatic Packet Reporting System) used by Amateur Radio operators to do object tracking, but as a side-feature, it supports a multitude of map formats.

We're currently partway through integrating GDAL/OGR, which will add a couple dozen new map formats, including TIGER. TIGER support exists if you compile in GDAL/OGR, but it currently doesn't allow customizing of line widths/colors per layer. Fortunately, some users have converted all of the TIGER data to shapefiles, hosted at http://xastir.tamu.edu.

Xastir uses an awk-like language that we call dbfawk for describing the attributes of line segments in shapefiles, which allows you to set the display to look like whatever you like, with some work.

Be default it does GPS tracking -- that's the initial purpose. If you're a Ham radio operator, you can even rig it up to a radio and TNC (radio modem) and see what other hams in your area are up to.

It can also download raster maps on-the-fly from various sources including the TIGER map server, TERRAserver, and maybe another. A "GEO" file describes the raster image source as well as the tiepoints (pixel->real coordinate) for ANY OTHER raster image you have. And the image source can be a local file or a remote file via HTTP -- so getting live radar background to your GPS tracking is a snap.

Items not yet added, but requested: routing, speed limit display, and 3D views -- all those were also requested by our users.

It has extensive documentation and includes explicit instructions on running it on MacOS X.

Dunno 'bout the others - but Xastir dosen't do route plotting - yet. It's 'on the list'.

However, in the meantime, it does have 'address lookup' - plug in your target addy and it'll show you where it is. From there - look at the maps to see how to get there. Zoom in or out for as much detail or over-view as you need.

Us ham types've been doing GPS navigatin not only of our own vehicles, but others as well for over 12 years now! I use a package called 'Xastir' and an on the air protocol called APRS.

Basicly, take a GPS receiver and a laptop (Not just linux, xastir will run on Windows too), a TNC and a VHF radio - use pretty much any map you'd care to use (local or online), current weather information, satallite imagry, NWS alerts, warnings, etc, etc, etc... See your track - find your way, see forest fires, floods, tornadoes, hurricanes....
The only limit is imagination

Just wanna check on someone? Use your web browser and visit Findu - plug in their callsign and see where they're at.

And no, you don't need a ham license to play along. Just to feed data into the world wide Information System.

Kinda neat to zoom in on 'the old country' and watch my firends in the UK on thier way to work as I'm get'n ready to call it a day, then keyboard to keyboard messaging with 'em along the way.....
And no air time fees

• Position (needs GNUstep)
• linuxNav
• roadMap
• gpsdrive
• Xastir

I found most of these projects at TuxMobil.org. I havn't actually used any of these programs, but I'm working on it!

Amateur ballooning can be quite a bit of fun. There is a small but active ballooning sub-hobby within the ham radio hobby. Ham radio is an ideal medium for transmitting telemetry from balloons, since we have access to cheap high quality (and high power) equipment.

I participated in a balloon tracking experiment not too long ago. The students of Timberlane Regional High School of Plaistow NH launched several high-altitude balloons carrying APRS transmitters, as a part of their CAPSAT (Coordinated Algebra (II) & Physics Simulated Satellite) project. I was able to track two of them. The balloons carried GPS receivers and ham radio Automatic Position Reporting System transmitters.

The launch was from Hopkinton NH. The first launch went well, and we received good signals from the balloon all the way out into the Atlantic ocean. This was quite a bit farther than they expected the baloon to travel, they had planned on recovering and reusing it :o It was still cool IMHO. Check out this kick ass map of the balloon's track.

The second launch was also a success, and the baloon only traveled about 50 miles before touchdown. Map is here.

The third launch went up with the GPS receiver turned off :/ At last check, it was at 00.000N 000.00W. They didn't launch any more balloons that day.

My tracking station consisted of a Kenwood TH-D7 radio and a PowerMac 7500 604e-180 running XASTIR on Yellow Dog Linux. The full results of the day (and APRS logs for the entire hamfest) are here.