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Contour mounding over a lake

flew a site with lakes and my contours over the lakes indicate mounds of water of up to 30 feet.  Not real.

Clues?

I figured it out.  Upon closeup inspection, the camera was seeing bathy

metry. 

Hi William,

Water surfaces have almost no visual content due to large uniform areas. Sun reflection on the water and waves cannot be used for visual matching or can, typically, generate noise points. Looking at the screenshots I would anticipate that some points were generated as noise and, in the end, contributed to the generation of the results (DSM, contour lines,…).

More in the Is it possible to generate the orthomosaic of water surfaces? article. 

The most direct way to account for the noise that is present on the surface of the lake is to incorporate a Surface object. To flatten the surface of the water, create a new Surface and digitize the vertices around the edge of the lake where the water meets the land. Once you have finished creating the Surface, check the Use for DSM and Triangle Mesh option. Step 3 must be processed again to take the new Surface into account.

Best,