Observing the Forest from Lidar and Radar Remote Sensing

Abstract

Lidar and radar are remote sensing systems that have proven their potential to accurately monitor forest structure characteristics. Both are active systems. They send their own pulses and measure the time elapsed between the transmission of the pulse and its reception after it has been reflected in a scatterer. However, Lidar employs laser light, while radar operates with microwaves, which allows the latter to operate under any weather condition. The viewing geometry is nadir and side looking for the Lidar and the radar respectively, among other differences. Mainly due to the availability of commercial systems, contrarily to radar, Lidar has been extensively employed by forest scientists and practitioners in the last decade. The analysis in parallel of both systems can help to introduce the use of radar data to the ecology community and to identify complementarities between them. This is particularly relevant in views of the forthcoming space missions, such as JEDI and Tandem-L.