In QGIS, I have a number of LIDAR scans of the same geographic location over a number of years. The actual values in the .asc files differ markedly (see image). Do the different value ranges for the different scans mean anything? As some are the same ranges, some are not. As its the same geographic location I would have expected the value ranges to be identical.
closed as unclear what you're asking by Andre Silva, LaughU, whyzar, Vince, Jochen Schwarze Nov 12 '18 at 16:18
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I don't know your dataset, but LIDAR DSM are made of point observation in a given field of view, which are resampled in a grid in your case. A few cm deviation between two date could make a small high feature visible (or not). A LIDAR also has several returns, so maybe your DSM correspond to the first, second and third returns, hence another difference in height.