Canon has a new version of their geek oriented point-and-shoot camera, the Canon PowerShot S100. My S90 essentially replaced my DSLR for walking around. The S100 is great; see this review. The cool new feature in the S100 is a built-in GPS for geotagging photos. I've tried to map my photos for years but without GPS in the camera it's been a hassle. Here's some notes on how the S100 GPS works.

The GPS antenna is in the top of the camera, above the lens. It's GPS only, no cell or wifi location, so it needs a view of the sky and won't work inside. There's three software GPS modes: entirely off, on when taking photos, or GPS tracking even when the camera is off. A warm start seems to find a position fix in 5–40 seconds. GPS location is written into EXIF tags in the photo and both Lightroom and Flickr understand the GPS format perfectly. There's no dedicated camera display of GPS data although you can see photos' locations in the viewer.

Digging deeper, exiv2 identifies 12 GPS tags in the JPEG and CR2 photo files. GPSVersionID is, there's lat/lon, altitude MSL (geoid corrected), timestamp, and minimal GPS status. Unfortunately location accuracy doesn't seem to be logged in the EXIF.

The GPS tracker is a nice bonus feature, I could see it being useful to document a photoshoot (although one wonders about battery life). Tracks are in standard NMEA format as a text file on the SD card. One fix is logged every 65-90 seconds. Each fix is logged both as GPGGA and GPRMC, basic position data. GPGGA includes HDOP and number of satellites and GPRMC includes speed and track. Note that as documented, the camera won't write GPS tracks to an Eye-Fi card but a standard SD card is no problem. Here's a sample log of me walking to lunch, see it mapped here. The track the S100 recorded is roughly accurate but missed logging my actual destination; compare to my AMOD dedicated tracker for the same walk. I'm pleased the S100 was able to log even when in my leather camera case on my belt.

The S100's GPS is a great addition to a great camera. It's not going to replace a serious GPS for navigation or technical measurements. But it's good enough for photos and terrific at making it easy to remember where you took your outdoor pictures.

Update: after a recent tourist trip to France I'm a little less excited about the GPS. It doesn't acquire position very quickly if you mostly keep the camera off, particularly for the first photos of the day. About 40% of my photos ended up without GPS coordinates logged, and that was after I was conscientious to stand around a minute or two letting the thing find position.
  2012-03-20 22:40 Z