MODIFIED HAND-HELD CAMERA SERVES AS INFRARED IMAGER ON ISS

摘要

INTRODUCTION A hand-held Nikon D3s camera was modified to allow near-infrared (NIR) photography from the International Space Station. This replaces the Crew Earth Observation (CEO) photography which was lost when NIR film capability was no longer available when onboard film cameras were switched to digital. The digital IR camera has an extended sensitivity in the near IR over color IR film so this offers an advantage over what was available with film. Color IR film was sensitive to 875nm where the digital CMOS array is sensitive to 1200nm due to the inherent sensitivity of CMOS detectors. Astronaut Don Pettit first initiated the camera conversion to collect imagery of the red emissions of auroras while on Expedition 30 of the ISS. Other applications include vegetation investigations for the daytime color IR images. With a selection of filters, CEO imagery can duplicate the standard LandSat bands and thus collect data that is commensurate with those historic images, offering current data that can be compared to that collected in the 1970's. Nighttime images are also enhanced since many natural phenomena such as noctilucent or polar mesospheric clouds, lightening, sprites, forest fires, and star light have extended red to near IR emissions. The Nikon D3s cameras were modified, tested, launched and first used in December 2011 once Don Pettit arrived at the ISS.