POSTER SESSION 4
10:30–12:30, Thursday, September 17
Poster Session | 1 | 2 | 3 | 4 | Schedule at a Glance
ABSTRACT 1205 | POSTER 248
Klidar VERSUS Kd: A REVISIT OF GORDON’S CONCLUSIONS
For oceanic waters, the relationship between the diffuse attenuation coefficient (Kd) and the lidar attenuation coefficient (Klidar) constitutes a pivotal scientific knowledge in the integration of active and passive optical remote sensing. Based on Monte Carlo simulations, Gordon (1982) concluded that, in general, Klidar is between Kd and c (the beam attenuation coefficient). More specifically, when the product of c and the lidar’s receiving radius at the water surface (R) is small, Klidar approaches c; on the other hand, when this product is large, Klidar converges toward Kd. Given the substantial receiving radius of spaceborne lidars, it is generally perceived that the Klidar values measured by such systems should be slightly higher than Kd and could therefore be approximated to Kd as done in many studies. However, recent measurement data from the ICESat-2 satellite reveal discrepancies with Gordon’s theoretical predictions. Through semi-analytical Monte Carlo modeling and Hydrolight numerical simulations, this study obtained Klidar and Kd for a wide range of water properties. It is found that Gordon’s conclusions hold for limited situations. In particular, the relationship between Klidar and Kd is highly sensitive to the scattering phase function as well as the single-scattering albedo. These findings provide more insights regarding the attenuation of lidar photons, as well as a cautious note on the application of Gordon’s (1982) conclusions regarding the relationship between Klidar and Kd.
Xiuling Wu, Xiamen University, [email protected]
Poster Session | 1 | 2 | 3 | 4 | Schedule at a Glance
