Hyperspectral Light Detection And Ranging(LiDAR) is a research direction that is being passionately advanced by both of the communities of LiDAR and hyperspectral remote sensing，because this frontier technology is of high potential for providing a feasible way to realize the beyond-3D RS.Some prototype systems have been developed and principally validated，but，so far，the fundamental technologies aiming at the core circles of its functioning are still in shortage.One of the representative circles is that the backscatting signals of different spectral bands are affected by the incidence angles of lasers，and this angular effect restricts hyperspectral LiDAR from achieving high-performance RS.In order to better grasp this angular effect that is caused by the morphology of object surfaces impacting the spectrum-location-synchronous data collection，this study explored its underlying characteristics，in the case of applying the Finnish Geospatial Research Institute-constructed hyperspectral LiDAR prototype system for measuring the trunk of a Birch tree.The rules of its different spectral bands responding to different laser incidence angles were analyzed and deduced，e.g.，for all of the spectral bands，their angular effects become weakening along with the laser incidence angles increasing.The findings of this study can provide new knowledge about the underlying mechanism of the angular effect，in favor of the following hyperspectral LiDAR researches on system development，data processing，and information derivation.
