Atmospheric CO2 Sensing with a Random Modulation Continuous Wave Integrated Path Differential Absorption Lidar

Kurzfassung

We propose an integrated path differential absorption (IPDA) lidar system based on a hybrid master oscillator power amplifier (MOPA) and single photon counting detection for column-averaged measurements of atmospheric CO2 . The random modulated continuous wave (RM-CW) approach has been selected as the best suited to the average output power obtained from hybrid and monolithically integrated MOPAs. A compact RM-CW IPDA lidar instrument has been designed and fabricated. High sensitivity and low noise single photon counting has been used for the receiver. Co-located 2 km horizontal trial path experiments with a pulsed system and insitu measurements were performed for comparison. The RM-CW IPDA lidar instrument shows a relative accuracy of the order of about 10% or 40 ppm CO2 concentration in absolute terms. The measurements qualitatively demonstrate the feasibility of CO2 IPDA measurements with a RM-CW system.