Design and laboratory tests of a Doppler Asymmetric Spatial Heterodyne (DASH) interferometer for upper atmospheric red line (630 nm) wind and temperature observations
Abstract
The oxygen red line (630 nm) has been used to obtain atmospheric F-region temperatures and winds from both ground and satellite-based instruments. The measurement requires high spectral resolution and sensitivity over a narrow spectral band; hence to date the instruments of choice have been Fabry-Perot and wide-angle Michelson interferometers. We have designed, built and are testing a Doppler Asymmetric Spatial Heterodyne spectrometer (DASH) for red line measurements. A DASH is similar to a wide-angle Michelson; however, it measures a much larger path difference interval which makes it possible to simultaneously measure multi-ple emission lines with no moving parts. The red line DASH interferometer design utilizes a Koester's prism as a beamsplitter to enable a quasi-common path configuration such that both arms use different parts of the same field-widening prism and diffraction grating. By choice of an appropriate prism glass, the interferometer was designed to be thermally compensated. In this paper we will discuss the design and laboratory tests of the interferometer and compare its expected performance with Fabry-Perot and wide-angle Michelson interferometers.
- Publication:
-
38th COSPAR Scientific Assembly
- Pub Date:
- 2010
- Bibcode:
- 2010cosp...38..855H