Generating Custom Garmin GPS Maps : Part 2

By Adam Newham

The following article is a follow up article on how to generate downloadable maps for Garmin's range of GPS receivers using one of the new GUI's that have appeared in the last year. This article will focus on the use of MapEdit. The GUI that originally shipped with GPSMapper is no longer supported by it's authors. I also took a look at GlobGPS, but in my opinion MapEdit has a better feature set/easier to use despite the fact that GlobGPS has calibration integrated into the application.

As with the original article, it is still required to have some form of basis for the map you wish to create. This process simply removed the requirement of tracing the files in OziExplorer and the tedious task of generating the text control file.

The basis for your map can be anything from; an existing track taken with you GPS, a set of waypoints, or for my example an aerial photograph. I currently use UsaPhotoMap in combination with BigJpeg due to its ease of use and that it gives both aerial photographs and topographic maps. If you are using this process I suggest that you take note of two waypoints that can be used later as calibration points.

This article assumes that the tools required are installed and configured as per the previous article.

The Example

USA PhotoMap

The following example will create a map from scratch using aerial photograph downloaded using TeraServer.

• Start UsaPhotoMap.
• Click File/New Map File. For you own map, enter suitable information. For my example enter the following for the Torrey Pines Municipal Golf Course, home of the Buick Invitational here in San Diego. Description: Torrey Pines GC, Lat -117.2453 Long 32.9045. Make sure the zoom is set to 1 metre/pixel, and then click File/Download Map Data. This should give you part of the golf course around the club house.
• Using the cursor keys move the screen/download map data until both the north and south courses are visible. Navigate to the top left corner of the golf course and press X. Cut and paste the coordinates into a text file, and perform the same operation for the bottom right. The coordinate will look something like this;

Top Left N 32.915435° W 117.255387° N 32° 54.9260' W 117° 15.3232' N 32° 54' 55.56" W 117° 15' 19.39" Easting 476,120 Northing 3,641,941 z11y18209 x2380 32.54 -117.15

Bottom Right N 32.889138° W 117.242589° N 32° 53.3482' W 117° 14.5553' N 32° 53' 20.89" W 117° 14' 33.32" Easting 477,310 Northing 3,639,023 z11y18195 x2386 32.53 -117.14

• Mark a couple of reference points that can be used for calibration. For golf courses I use the center of the greens as they are usually easy to detect. Road intersections are good for other types of maps. When you exit the UsaPhotoMaps application, a xml file will be created with the waypoint information. However as I personally don't like having to type in all of the information, I save the waypoints to my GPS which I then load back into OziExplorer. At the moment I don't know how to save the waypoints in UsaPhotoMaps into a Ozi compatible file directly. So if your unable to save to a GPS unit and export into Ozi from it, you'll have to write the waypoints down.
• Start BigJPEG (should be in the UsaPhotoMap directory), using the data just captured enter the coordinates for the top left and bottom right. (tip: if the program complains that a specific DTA file cannot be found and the files exists in the directory, close the UsaPhotoMaps application and rerun BigJpeg)
• Create a working directory e.g. "My Maps" in your home account.Copy the generate BigJPEG file/jgw file to your working directory and rename to something relevant e.g. torreypines_gc.jpg/jgw. (the actual map is below for reference if you wish to skip the steps above)

OziExplorer

• Start OziExplorer.
• For calibration I'm going to use North Course hole 15 (top right @ lat="32.914054" lon="-117.246742") and South Course hole 12 (bottom right @lat="32.891984" lon="-117.249686"). Click "View/Lists/Way Point List". Click Add.
• Enter the information for the two points (make sure your units are correct. (tip: Ozi requires that the decimal part has . prefix). Save the way points to a file by clicking Save disk icon, "Save Waypoints to file" and save to torreypines_gc_cal.wpt
• Now it's time to calibrate the map (if your using the evaluation version, you will need to convert the JPG to a BMP before doing this). Click "File/Load and Calibrate Map Image". Select the file that was created from using UsaPhotoMaps. Click the "Point 1" tab and navigate to the same location as N15, click the center of the green, now click the "Wp" button next to it and use N15 as the reference. Click"Point 2" tab and do the same for S12. The further apart and more numerous the calibration points are, the better the calibration.
• Save the file as torreypines_gc.map

MapEdit

• Start MapEdit.
• Click "File/Open" select torreypines_gc.map
• Zoom to a scale that gives detail for your screen size/resolution (30m is about right for me) and navigate to to where the club house is (right hand side/half way down the map @ lat="32.90448" lon="-117.24541"). Select the "point tool" on the tool bar by selecting the arrow between the wand tool and rectangle-cut tool. Select the club house, when the "Change region type" dialog appears, navigate to symbol 0x0040 - Golf and select it. A small white rectangle will now appear of the map - enter "Torrey Pines Golf Course". A POI (a.k.a. Point of Interest") has now been created.
• Repeat this for all of the holes on the course. I created two files with this information for north and south courses respectively.
• Click "File/Save as" and enter name. This saves all of the POI's as a txt file compatible with gpsmapper.
• Creating the fairways for the course is similar to the POI's. This time using the region tool select "Polygon" and draw round one of the fairways. When done, hit escape and select "Golf Course - 0x0018" in the dialog and then add a description such as "Fairway N13". The new region will now be shown in red hash overlaid on top of the map.
• Repeat the above process for the remaining holes/water hazards etc. For my example I used "Lake - 0x003c" for the water hazards. During the creation phase, if you make a mistake, the polygon can be edited by selecting the "Move Points" tool on the tool bar, zooming in over the point you wish to change (the cursor will change over an movable point) and drag and drop the points. Additional points may be added by right-clicking the mouse and selecting "Add Points".
• If you decide you don't like the name that you entered in the previous steps, it may be renamed by selecting the object, right-clicking and selecting "rename". Other options on this menu are "Change Type" and "Move Points".

The following file is a partial map of Torrey Pines.

Tip: If you have multiple maps, using the "File/Add" option you are able to import each of them into the work area. Then using the mask option select the area of interest and right-click cut outside. This is useful when wanting to perform the equivalent of a merge and want to avoid having a "blank" area's just outside of your custom map when used with Garmin supplied maps.

Generating Map

• Finally we are ready to generate the map. But before we do we want to make sure all of the maps properties are correct. Click File/Map Properties. For ID Enter 10000013, Name: Torrey Pines Golf Course. RTE_size: 6000, TRE_margin: 0.000. Leave the other options at their defaults.

• Click the levels tab, and the "Insert before" tab. This will add two levels. As a golf course is pretty small and detailed we want the maximum resolution. Higher resolutions would result is a jaggy look. Highlight level 0 and click change. Make the Bits: field 24 but leave the zoom range at under 1.2Km. Highlight level 1 and click change. Continue with options until it looks like the image below.

Generating the Map

• Finally we are ready to generate the map. For this we will need a DOS prompt, getting this will depend on your OS for Win2k/XP using click Start/run and enter "cmd" (without quotes) and you should have prompt. Change directory to where you saved all of your files.
• Run the attached files. This will invoke the cgpsmapper utility with the correct options to generate the actual map in the correct Garmin IMG format and a preview file that can be used with MapSource. (When you have more maps to add, simply modify the attached version to expand the auto-generation of the maps and previews)
• Now copy the two generated IMG files (100000013.img/GolfCourses.img) and the TDB files to the location that was configured in your registry.
• The new maps should be available in MapSource.

Tool Installation

The following tools need to be installed (listed in the order they are required)

• UsaPhotoMap (BigJPEG)
• OziExplorer
• MapEdit
• GPSMapper

FAQ

The following is a selection of commonly asked questions I've received since I wrote the first article.

Q: Can I download a image (scan/photograph or other bitmap image) directly to my GPS receiver?

A: No, GPS receivers require specially formatted maps which are in "vector" format i.e. a sequence of coordinates representing individual lines rather than "bitmaps" which typically represents an image such as a photograph.

Q: Do you know of a program similar GPS Mapper for my brand "X" receiver

A: There might well be, but as a Garmin owner I am unfamiliar with other brands that might or might not have comparable utilities available for them.

Q: GPSMapper doesn't seen to generate maps correctly, what is wrong?

A: Make sure that you're able to generate the example map that comes with GPSMapper. It's located in the directory where you installed GPSMapper under SampleMap or Test_map. Note, I am not the author of this program. I've simply written this How-To FAQ to assist enthusiasts.

Q: I have Garmin's "X" GPS receiver. Will this method work for it?

A: Any of Garmin's GPS receivers that have mapping capability will work with this process. Garmin GPS receivers that support POI should still be able to display POI information contained in the maps, but will not be able to display the maps themselves.

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