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Moagu doesn't "vectorize" the data except in the coarsest sense of the word, so it doesn't keep attribute data. You could create a Moagu map from the NLCD raster data, but it's going to draw and pan very, very slowly.

Converting the map into KMZ format with minimal compression, and using it in a Colorado/Oregon/Dakota is probably the best approach.

If you can live with older data with a coarser categorization scheme, there's LULC data in shapefile format available for free:

http://www.webgis.com/lulcdata.html

[Don't install KMZ files created with G-Raster into your Garmin's internal memory - put them into an external memory card in an external reader. Just a precaution for use with the Garmin beta software, and version 1.0 of G-Raster. That way, if there's a problem with the overlay, you can always just remove the card from the GPS unit.]

Been plugging away the last week, and now have the first version ready of G-Raster, a program that will load georeferenced imagery, tile it automatically, and create a Garmin-compatible KMZ file.

Don't install KMZ files created with G-Raster into your Garmin's internal memory - put them into an external memory card in an external reader. Just a precaution for use with the Garmin beta software, and version 1.0 of G-Raster. That way, if there's a problem with the overlay, you can always just remove the card from the GPS unit.

Download link to most recent version can be found on this page:

http://moagu.com/?page_id=155

Interface is fairly straightforward:

1. Open your graphic file; supported formats are:

a. Files with embedded geodata (GeoTiff, NOAA BSB, MRSID, IMG)
b. USAPhotoMaps Big JPEG files (UTM, you'll need the UTM zone)
c. Generic graphic files with UTM worldfiles (you'll need UTM zone, and specify datum and hemisphere)
d. Generic graphic files with worldfile in any coordinate system (you'll need to specify the EPSG code)

2. Process the raster graphic file

3. Set basic options (overlay name, JPG compression, transparency in Google Earth). You can also rescale the image by a factor >= 1.0 to reduce its size (reduces resolution, but also reduces the number of tiles).

4. Create the overlay.

You should definitely check it in Google Earth to make sure it's in the right position; just remember that Google Earth imagery can be off from 0 to 100m depending on where you are. If it looks good, put it in the \Garmin\Custom Maps directory on the external data card and test it out.

Limitations:

- Maximum file pixel size is 100 million; larger than that, and you have the option of cropping it down to a smaller size

- Tile size is set to be the largest compatible with the image dimensions and a max tilesize of 1024 pixels.

Mostly functional for free (though I do ask for a small registration fee if you find it useful)

Grab a copy of DNRGarmin:

http://www.dnr.state.mn.us/mis/gis/tools/arcview/extensions/DNRGarmin/DNRGarmin.html

You can create a CSV text file of your coordinates, specify the input coordinate system using the Set Projection command, then have them converted automatically to lat/long. You can then send them directly to your Garmin, or save them in GPX format.

In the Heading section of Setup, if you select North Reference to be Grid or User, you can set a custom value for magnetic variation. If you set it on Magnetic, it looks like it automatically calculates and displays an unmodifiable current variation value; at least, it's correct for my current location. And on True, there's no variation visible or set.

Corpscon was my first link ...

Theoretically, there's one set of circumstances where having WAAS turned on might degrade accuracy. If you have a 12-channel unit, and there are 12 or more GPS satellites visible, having WAAS enabled would "crowd out" one of the available slots for GPS satellites. If the missing satellite was in a key area for the best geometry, you could in theory get slightly more accurate positions by turning WAAS off to free up that one satellite spot.

In practice, though, this is so incredibly unlikely to happen that for accuracy, you're always better off having WAAS turned on. It will also reduce battery life slightly, but not by very much.

As long as there's some way for your mapping software to know that a particular point you're entering is in one or the other datum, then yes. If it can't, it will show the points as being about 200 meters apart (at least in the SW US).

Try this one:

http://freegeographytools.com/2007/coordinate-converters-i-nad-conversions

Or this one:

http://freegeographytools.com/2009/online-coordinate-conversion-and-epsg-code-lookup

If not, take a look at other posts in the "coordinate conversion" category. But every solution will have a learning curve associated with it.

You would have to select only small chunks of the coastline, which could results in a large number of segments to process. It's quite possible that you still might wind up the maps requiring more memory than you have. With such an old model, the processor speed may not be up to the task of displaying the maps with any reasonable speed. Finally, I'm assuming that this is a black-and-white display, and that will complicate the job of making a map that's usable. I wrote Moagu, and while I'd like to sell another copy, it's quite likely that it simply won't do the job for you.

Eight years is a big gap in technology; it may be time for you to think about buying a new GPSr, or a used model of recent vintage. You'll get a color display, more memory, more speed, more features, and more accuracy for less than what you probably paid for your current unit.

I wouldn't get too hung up on this - IDL is only needed to run DEM2Topo, which you only need if you're trying to create topographic contours. For that matter, for what you want (property boundaries), the full Garmin tutorial on this site may be a bit much. I've got some links to other tutorials on this page:

http://freegeographytools.com/2008/make-your-own-topo-maps-for-a-garmin-gps-unit

Wow - I hadn't heard that you could run OziExplorer CE on a Triton. Can you post a link to the install process? Also, do you know if it runs on the less expensive Triton units (300, 400,500)?

There are many ways you could go about doing something like this. Here's one off the top of my head.

1. Scan the map into digital format (which you've done)

2. You now have to assign geographic coordinates to every point on the map, a process called "registration" or "georeferencing". This is complicated a bit by the fact that it's a hand-drawn map, and thus is likely not drawn with high degree of accuracy. So the georeferencing will need to include a process called "rubber-sheeting", which warps features on the map to put them in the right position.

There are many programs, free and paid, that can do registration, but far less that also do rubber-sheeting. There's a free online service called Map Rectifier that will do both registration and rubber-sheeting, and produce a calibrated map:

http://freegeographytools.com/2008/online-raster-map-georeferencingregistration-with-map-rectifier

3. Now that the map is calibrated, you have several options:

a. Use a program like Moagu or MapWel to directly convert it into a Garmin-compatible format.

b. Load the map into a simple GIS like MapWindow, and create georeferenced vector files (shapefiles) by manually tracing over the features you want.

http://freegeographytools.com/2007/intro-to-mapwindow-gis-iii-shapefile-editing

You can then convert these shapefiles directly into GPS waypoints, routes or tracks using the free version of GPS Trackmaker:

http://freegeographytools.com/2007/a-better-solution-for-gps-exportimport-with-google-earth

c. Or you can enter the fabulous world of Garmin mapmaking by importing the shapefiles into a program like GPSMapEdit, MapDekode, MapMan or Mapwel, and create your own Garmin mapsets.

The native coordinate system for all GPS is geographic (latitude/longitude), WGS84 datum. If you set a different coordinate system for display, the unit does the coordinate display conversion on the fly, but all data you display and save (waypoints, tracks, etc.) is still in geographic/WGS84. MapSource sends all data to the GPS in that coordinate system, and also receives any data from a GPS in that coordinate system. As you say, "MapSource magically handles everything".

NAD27 and NAD83 aren't projections, they're datums, different shapes of the world that flat maps are projected onto; NAD83 is virtually the same as WGS84, within a meter across the entire US. It's not that the GPS units are so smart that they correct for different datums, it's that changing the datum only changes the coordinate displays; the data displayed stays in geographic/WGS84.

Thanks, Dan, and also thanks for creating installers for the Nantucket map I used in the tutorial. Let me know if there's anything else you need. And obviously, if anyone runs into problems with the tutorial, drop me a line at [email protected] and I'll see what I can do about making it better.

The freeware GIS MapWindow can do this.

http://freegeographytools.com/2007/intro-to-mapwindow-iv-advanced-vector-tools

Make sure the GIS tools plugin is enabled, then load in the shapefile you want to clip, and the polygon you want to clip with (or create the polygon with the shapefile editor). Then use the Clip Shapefile With Polyon tool to clip the shapefile with the polygon, You can clip point, line or polygon shapes.