Lag-angle compensation technique applied to a fast-scanning long-range Doppler lidar system

The coherent Doppler lidar SKIRON3D is LEONARDO's solution to the problem of identifying dangerous wind hazards at airports. Fast beam scanning while maintaining a long operational range is the key enabler for updating alerts and warnings according to operational requirements. One downside of fast beam scanning, though, is the decrease of the heterodyne efficiency due to the mismatch between the transmitting and receiving beam caustics. At a typical scanning speed of 12°/s, this leads to a decrease of approximately 20% in operational range. This so-called “lag-angle effect” can be compensated either by a moveable receiver or transmitter. LEONARDO's solution is a continuously tilting piezo-mounted receiver mirror to compensate for the lag-angle losses. Instrument setup and measurement results for long-range operations using our lag-angle compensation technique (LACT) will be presented in this contribution.