Many of our flights are near or over bodies of water. These do not triangulate correctly of course and we need to eliminate this data. Frequently we will already have a 2d-polyline in a dxf representing the shoreline that could be used to trim a majority of the bad data. Is this something that can be added to survey to speed up processing. Right now the only way for us to achieve this is entirely manually or partially through alternate software.
Thanks again!
Hi Brian,
That’s an interesting idea, thanks for sharing it! As a workaround today, I would use that polyline, import it to Survey, and on import you’ll be asked if you want to assign a single Z value to 2D objects. Give it the elevation of the water body, then once imported, set that layer to be a terrain layer. Make sure that any points within the boundary aren’t in the terrain class, and then when you create a grid, it’ll be ignored. On TIN creation, the Z value of the line can be applied as a breakline, and you’ll get a flat water body. Does that help? Of course, it won’t have any impact on the processing of the images, but it should at least clean up the outputs.
Here’s the effect you get in the bottom of a quarry:
We are actually in the process of submitting our flight of the surrounding shoreline alongside our bathymetric survey of the waterbody, so we would prefer not to generate terrain data over the waterbody. As well, the flight took a few weeks to complete, roughly 6 Sq. Kilometers just for the water itself, so the water elevation fluctuated up to 30cm depending on the date of the flight. Is there a way to select a collection of points within a polyline boundary? Selecting and classifying them manually would be days of effort. Any way to use a polyline as a boundary for selection would be extremely useful.
