This is a cracker. Use your existing PDA’s GPS receiver to write a GPX log, and then use it to tag your photos with the exact location where they were taken later, with no connection between the GPS receiver and the camera necessary!
Here’s how it works. It’s all about time. A GPX log just records the raw data coming from the GPS receiver – basically just a very accurate time together with an exact location, at intervals along your journey. Digital cameras tag the photos you take with the time and date they were taken – so all you need is a piece of software that’s smart enough to take the timestamp and use the GPS log to turn it into a position.
Here’s one way to do it:
First, I needed a program for my PDA phone: a t-mobile MDA Vario (also known as iMate K-JAM, Qtek 9100, HTC Wizard, etc. etc. – man, I hate re-badging like that) running Windows Mobile 5. It doesn’t have a buit-in GPS receiver – my next phone will (HTC Kaizer) – but I do have a Bluetooth GPS unit which works just fine for the moment. I wanted a program that would also allow the GPS port to be connected to another program while the logger was active, so I could still use it for navigation. What I found does exactly that: I can still use TomTom Navigator at the same time. The logging program is called SunsetGPSLogger and it works a treat. It does have a couple of foibles, but what do you want for free? It doesn’t remember what port your GPS receiver is connected to, so you have to set that every time you launch it. It has a hard-wired path to the place where it will write the logs – and that path is in /Storage Card, so you’d better not have an empty expansion slot. It also has some useful smarts, though: not least the clever algorithm which only writes “good quality” waypoints to the log. Anyway, it writes lovely, compact logs – now I need something to use those logs to tag my photos.
That’s where GPicSync comes in. Again, it’s free, and again, it’s nifty. You point it at the GPS log, and you tell it where the photos are, and you press a button. Actually, it’s also a good idea to tell it the difference between your camera’s clock and the proper GPS time: it’s less easy to keep camera clocks spot on than those of a PDA.
Press the button Synchronise button, and off it goes – writing to the EXIF tags of your photos, and even backing them up if you want, in case it messes things up. It even has a button to show the results in Google Earth once you’re done. Very, very nifty.