The high‐resolution doppler imager on the Upper Atmosphere Research Satellite

Abstract

The high‐resolution Doppler imager (HRDI) on the Upper Atmosphere Research Satellite (UARS) is a triple‐etalon Fabry‐Perot interferometer designed to measure winds in the stratosphere, mesosphere, and lower thermosphere. Winds are determined by measuring the Doppler shifts of rotational lines of the O 2 atmospheric band, which are observed in emission in the mesosphere and lower thermosphere and in absorption in the stratosphere. The interferometer has high resolution (0.05 cm −1 ), good offband rejection and excellent stability. This paper provides details of the design and capabilities of the HRDI instrument.