Regarding the definition of BEV:

[liuzhihua-web]

Thanks to the authors for your hard work and sharing!
I have a question: I would like to know why you call this projection in equation (2) as a BEV, in other research work, such as FusionVLAD, BEVPlace, their BEV is obtained by projecting onto the XY plane.

Related Blogs and Papers:
FusionVLAD: A Multi-View Deep Fusion Networks for Viewpoint-Free 3D Place Recognition
BEVPlace: Learning LiDAR-based Place Recognition using Bird’s Eye View Images
http://ronny.rest/tutorials/module/pointclouds_01/point_cloud_birdseye/