I have created and loaded a map onto my BlackBerry that can be used off line with the internal GPS. The advantage of this is that maps other than Google and BlackBerry maps can be displayed; OSM and OS for instance and data charges are therefore not incurred if applicable.
What I did was:
Created a map of the area I commonly ride in by grabbing screen shots from a suitable website. (Could also scan in a map.) These were stitched together using an image handling program, I used GIMP2, and saved as a .png file.
The map was then calibrated using ‘Map Calibrator v2.6’ using 4 points in the corners – lat/long references taken from the donor website.
I then used ‘TB Cutter 0.5.01’ to chop up the map into tiles for display on the BlackBerry.
The BB runs a program called ‘TrekBuddy’ which works very well.
However!
I have a display error of about 500m that I am struggling to account for. The location displayed on screen is consistently 400-500m to the S-SE of where it is supposed to be even when I am at one of the locations that I used as a calibration point. The GPS in the BB returns coordinates that are no more than 30m away from the coordinates of the calibration point when AT the calibration point!
Anyone any thoughts?
How to do it
