Airborne Testing of 2-μm Pulsed IPDA Lidar for Active Remote Sensing of Atmospheric Carbon Dioxide

The capability of an airborne 2-μm integrated path differential absorption (IPDA) lidar for high-accuracy and high-precision active remote sensing weighted-average column dry-air volume mixing ratio atmospheric carbon dioxide (XCO2) is demonstrated. A test flight was conducted over the costal oceanic region USA to assess instrument performance during severe weather. IPDA targets CO2 R30 line using high-energy laser transmitter. HgCdTe avalanche photodiode detection system used in receiver. Updated model included range correction factor account platform attitude. Error budget XCO2 retrieval predicts lower random error longer length. Systematic dominated by water vapor (H2O) through number density derivation, followed H2O interference ranging related uncertainties. results 404.43 ± 1.23 ppm, as compared 405.49 0.01 ppm from prediction models, consistent reflectivity steady elevation surface target. This translates 0.26% 0.30% relative accuracy precision, respectively. During gradual spiral descend, 404.89 1.19 404.75 0.73 indicating 0.04% 0.23% accuracy, Challenging cloud limited precision 2.56% 4.78%, respectively, due errors.