An accuracy assessment of a GPS- enabled digital camera

An accuracy assessment of a GPS- enabled digital camera

As the consumer market embraces digital imaging, digital cameras are becoming less expensive while producing higher resolution images. This explosion in camera architecture combined with GPS technology and consumer grade photogrammetric software can provide for noncontact, inexpensive, safe and practical measuring systems which can be used for direct geo-referencing of points of interest and 3D modelling.

This study investigates the accuracy of a measuring scheme based on a GPSenabled digital camera (Ricoh 500SE) and photogrammetry software (PhotoModeler by Eos Systems Inc). The coordinate values of selected target points determined by this close-range photogrammetric system are compared to the coordinates of the same target points computed using a surveying total station. The target points were not chosen to satisfy the photogrammetry technique but were in fact natural targets part of a noise barrier located along a busy motorway.

The results of this study showed that measurements with the proposed system differed from the more precise surveying measurements by an overall positional accuracy in x, y and z of 0.5 m. This expected accuracy result was essentially a function of the accuracy of the GPS unit and when a more accurate version becomes available and is incorporated with the camera, the accuracy should reduce to that approaching a total station. The efficiency of the GPS-enabled camera system was the important point disclosed by this study.