Real-time laser Doppler anemometry for optical air data applications in low aerosol environments

Abstract

Laser Doppler anemometry (LDA), sometimes also referred to as cw Doppler lidar, is a promising optical technique for the measurement of primary flight data such as true air speed, angle of attack, and angle of sideslip. Multiple flight campaigns have shown the potential of this technique for future air data systems. However, LDA remains challenging in low aerosol environments at cruise altitude, and the high raw-data bandwidth of LDA sensors impedes real-time operation. In this work, we present a real-time preprocessing scheme, which is optimized to handle the signal structure of single-particle scattering events. We discuss how this scheme is implemented on system-on-chip field-programmable-gate-array hardware and how it is used with a four channel laser Doppler anemometer.