Figure 2.

Equipment and camera specification for potential instrument-based surveys for polar bears and seals in the eastern Chukchi Sea. As with previous IBS surveys in the Bering Sea, a DeHavilland DHC-6 Twin Otter aircraft (a) would be equipped with three long wavelength infrared (LWIR) thermal cameras (FLIR SC645) and three high-resolution digital single-lens reflex (SLR) cameras (Canon 1Ds Mark III) mounted through its bellyport (b). Blue lines (c) indicate thermal camera swath width for each camera, while red and green polygons represent the expected footprint of SLR photographs. Flying at a target altitude of 300 m, this configuration results in a thermal swath width of 470 m of which automated digital photographs cover ca 84%.