<title>Near-infrared sky brightness monitor for the South Pole</title>

Abstract

ABSTRACT The antarctic plateau has the potential for being the best site on Earth for conducting astronomical observationsfrom the near-infrared to the sub-millimeter. Particular gains are expected in the 1 to 5micron region, wherethe high altitude, low water vapour content, and low thermal emission from the atmosphere combine to createobserving conditions unequalled elsewhere on the surface of the earth. We describe an instrument, the InfraredPhotometer-Spectrometer (IRPS), that we are using to quantify site conditions at the South Pole by measuring thenear-infrared sky brightness. We also describe some ofthe unique problems associated with building instrumentsto work in Antarctica.Keywords: near-infrared, Antarctica, astronomy, site-testing 1 THE ENVIRONMENT AT THE SOUTH POLE The US Amundsen-Scott South Pole Station is located within a few hundred meters of the Geodetic SouthPole, at an altitude of 2900 m. Centrifugal and temperature effects reduce the air-pressure to the equivalent ofbetween 3200 and 3600 m depending on the weather. At these altitudes, there is noticeably less oxygen in the air,leading to sleeping difficulties, reduced mental capacity, loss-of-breath after moderate exercise, and sometimes