A Visible and Near-Infrared Scanning Photometer for Field Measurements of Spectral Albedo and Irradiance under Polar Conditions

Abstract

The design and operating characteristics are presented for a visible and near-infrared scanning photometer which can measure incident and reflected spectral irradiance from 400 nm to 2 450 nm. The instrument is designed to record over 98% of the solar radiation incident upon and reflected from the Earth’s surface using a turret-type cosine collector and a circular variable interference filter. The apparatus has been tested successfully on Arctic sea ice at temperatures down to –20°C. It is self-contained and easily portable, and its mass is less than 16 kg. Some preliminary results are presented.