Both the geometric and spectral information of the target are available with the hyperspectral light detection and ranging (LiDAR) in a single measurement. This advanced technique extends the scope of imaging spectroscopy to spectral three-dimensional (3D) sensing. However, two major geometric radiative effects exist in hyperspectral LiDAR, namely, the distance effect and incidence angle effect, which seriously restrict its quantitative remote sensing applications.
A research team led by Prof. Niu Zheng from the Aerospace Information Research Institute (AIR), Chinese Academy of Sciences (CAS) has proposed correction algorithms while studying the geometric radiative effects existing in hyperspectral LiDAR. The results were published in ISPRS Journal of Photogrammetry and Remote Sensing and IEEE Transactions on Geoscience and Remote Sensing. The researchers discovered that the analysis and correction of the distance effect and incidence angle effect can be carried out independently. They proposed a piecewise function model that couples a quadratic function and an exponential decay function to analyze and correct distance effect and developed an improved Poullain algorithm to analyze and correct the incidence angle effect. They found that distance effect originates from the system itself, and all wavelengths have a unified distance effect function. Based on this, they proposed a piecewise function model that couples a quadratic function and an exponential decay function to analyze and correct distance effect.
