GPS reborn

On the first of May 2000, President Clinton ordered that the GPS signal be unscrambled, increasing the resolution available to users considerably. A resolution of 20m became quite realistic with the basic handheld receivers of the day. As a keen hill walker I'd contemplated GPS previously but suddenly I felt it was the way ahead.

I purchased a Garmin 12XL which is waterproof and will work off external power supplies of up to 30V. At the time it was a well reviewed unit, but even then, low on functionality. For some time I experimented with saving tracks and waypoints using GPSu which is an excellent little Windows application at a low price. However I didn't get into a habit of doing this, mainly due to its limited mapping facility. I bought an Anquet map package which was pretty good but heralded the death of our Windows box. It was replaced with a G4 Mac Mini as I was tired of Windows crashes and didn't want to trouble my SO with Linux. Two years ago there didn't seem to be anything simple and cheap for using a GPS unit with OSX. The 12XL was then back to being an excellent source of grid references when I was 'unsure of my position'.

For the last 18 months I've been documenting the local Rights of Way for my own use by taking digital photographs of signage and the track condition but it was a bit fiddly remembering which image was which. Then I heard of Geocoding and that seemed to be a way forward especially if it could be coupled with Google Earth.

Now there are a lot of freeware or open source programs for using GPS units with OSX. The ones I've tried out are:

• GPS Connect - a basic upload and download utility
• GPSBabel and its GUI frontend for OSX - a utility to convert between 'every' GPS file format and communicate with GPS units
• Exiftool - the perl script responsible for stuffing GPS data into image files

I was working towards a chain of programs to tag my images but stumbled across GPSPhotoLinker which does it all. Easy to use and a good introduction without getting into too much OSX setup trauma. I've only done a trial walk near home so far but it's looking good...