Doppler Asymmetric Spatial Heterodyne (DASH) Light Detection and Ranging (LIDAR) Receiver

The Doppler Asymmetric Spatial Heterodyne (DASH) spectrometer concept was first proposed in 2006 for measuring Doppler shifts of single or multiple, near monochromatic signals and specifically for the passive measurement of atmospheric winds in planetary atmospheres. DASH interferometers have since been proposed, built and used for the passive remote sensing of Doppler shifts of naturally occurring, telluric airglow lines to infer thermospheric winds. In particular, ground based measurements have been conducted and a space based DASH instrument payload for measuring thermospheric winds from low earth orbit is currently part of a NASA Explorer mission Phase A study. Up to now, DASH interferometers have only been implemented and proposed for instruments that perform passive detection of naturally occurring thermospheric airglow. Using DASH interferometers within the active detection system of a Doppler wind Light Detection and Ranging (LIDAR) system was recently patented in the United States of America. This paper briefly explains this concept and its potential advantages.