I have obtained LiDAR data from my environmental agency in order to obtain the relative heights of each watercourse station. A far as I know, LiDAR signals do not get returned over water bodies. However my data does in fact show many last returns. Would these returns be reflections from nearby objects (vegetation)? The height values do however show that there is a relative drop from the river bank returns to the points returns on the water surface.
The image shows the course of a river and the LiDAR surface returns.
Could anyone explain why I get returns over water bodies and whether these returns have any practical use?