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Sometimes you wish to use your GPS and data enabled mobile phone to navigate but either you do not have a data signal, or the map you require is not available through Google or BlackBerry maps. This short article will talk you through how to create a map to be used with TrekBuddy on your mobile, PDA or BlackBerry.

When mountain biking or trekking its great to have Google Maps to help guide you, but when you lose your data signal you lose your map. Additionally maps such as Google Maps in either map or ’satellite’ view do not have the required detail, missing important features such as contour lines. In the UK Maps such as Ordnance Survey’s Explorer series range with a 1:25 000 scale provide the required amount of detail. These maps can be purchased in digital format from Memory-Maps or can be scanned. It is also possible to buy maps from Memory-Maps that can run directly of your smartphone without following this procedure.

How To

1.Obtain your map in one large file in JPEG or PNG format. If you have mapping software such as Memory Map, you can export the map by using the menu and going to Menu Bar->Map -> Image Export. You require a registered version of memory map to unlock this functionality. This creates a BMP file, this may be quite large at around 15000 by 10000 pixels and 500MB in size.

2. Crop your map to the required area using an image editor that can deal with large images, I suggest GIMP 2 which you can download here, using the save as function to create a PNG file. This will reduce the file to a more manageable size.

3.Next you need to calibrate your map using Map Calibrator v2.4. This can be downloaded from here. Once this is installed load your full size map, and move to each of the 4 extreme corners of the map. For this you need to pick a point on the map you know the true latitude and longitude of , you could pick a feature such as a building but I prefer to pick the intersection of 2 grid lines. Right click on the map and “add new calibration point”, carefully enter the true position of your point WGS84 format. Be careful to correctly specify the N/S E/W portion.

If you do not have the exact location for 4 features, you could use StreetMap, left click on the grid line or feature on the map and there is a link at the bottom of the page which will give you the position of where you clicked in several formats. You can also convert the UK Grid References into the correct format using this converter.

Now save the file by simply exiting Map calibrator, it should produce a .gmi calibration file.

4. Now load the excellent TB Cutter, this can be downloaded from here. Specify the location of your files and accept the default formats. Depending on your PC speed and size of map this may take a few minutes. You can now copy the map to your mobile phone, you will need to copy the .gmi, .set file and the set folder which contains the tiles of the map to the maps directory of your mobile, more details of how to do so can be found in this article.

Problems and Pitfalls

1. If you use Memory-Map to save full size 1:25 000 scale maps the maps may not be saved, presumably because of low memory, try viewing each half of the map on screen in turn and then exporting it as 2 files, this can then be stitched together in GIMP.

2. If you scan maps or download maps from Memory-Maps, there may be copyright implications. It is suggested you check your licence.