Photogrammetry

Photograph of gray whale cow/calf pair which will be used to gather information on their health. Photo: NOAA Fisheries

Photogrammetry involves making quantitative measurements from photographs and requires the use of scale (= distance/focal length) to determine the real size of the images.  We use photogrammetry to provide data on length, growth, and body condition to understand the health of individual whales and dolphins. Images are also used to identify individual animals for mark/recapture studies. We also use photogrammetry to estimate cetacean abundance and their school structures, as well as to calibrate visual marine mammal observer group size estimates.

Over the past 40 years, as imaging technologies have advanced, we have successfully collected aerial photogrammetry data for many cetacean species worldwide, study areas include the Pacific Ocean, Atlantic Ocean, Bering Sea, and Southern Ocean waters around Antarctica. Images have been taken from land, boats, manned aircraft, and UAV (Unmanned Aerial Vehicles).  We use these same techniques to study seals and sea lions as well.