Automatic geocoding in HoudahGeo matches photos to a GPS track log. A track log is a record of where you have been. A GPS app or track logger records your current position and the current time. It does so every few seconds and thus creates a breadcrumb trail of your travels.
HoudahGeo figures out where you took a photo by matching the timestamp on the photo with the times in the GPS track log. While the GPS device gets accurate time information from satellites, your camera clock is probably not accurate. Most cameras also do not record time zone information: the photo coming out of the camera may say it was taken at 12 PM, but there is no telling if that is to be understood as 12 PM east coast or west coast – a 3-hour difference.
Timestamps in HoudahGeo
HoudahGeo needs to know the exact time a photo was taken. That is why HoudahGeo asks about camera clock settings when you import images.
There are 4 ways you can tell HoudahGeo about your camera clock settings. The first 3 are found in the Load > Camera Setup… panel. This panel pops up automatically when you import photos that lack time zone information.
You can skip Camera Setup… – accept the current settings – and proceed to import more images and GPS track logs. We will correct the camera clock settings later by matching a key photo to a spot on the track log. Continue reading HoudahGeo 6: A New Way of Lining Up Photos with a GPS Track
