Wavecams topographies are validated by comparison with independent topography measurements: DGPS and Lidar data if available.
Here is an example of validation with DGPS measurements acquired in the central part of Etretat bay on the 10th of January 2020, through the following 3D interactive figure (to move inside the figure: left clic(rotation), mouse wheel( zoom), right clic(translation)) :
After interpolation of DGPS data on our topography grid, we obtain very good validation results: MAE=27cm, RMSE=32cm (MAE: Mean average Error, RMSE: Root Mean Square Error)
Here is an example of validation with Lidar measurements acquired in the whole Etretat bay on the 28th of August 2019, through the following 3D interactive figure (to move inside the figure: left clic(rotation), mouse wheel( zoom), right clic(translation)) :
Good validation results are obtained, with MAE=39cm and RMSE=50cm, knowing that the vertical precision of Lidar measurements is about 20 cm.
Even though the DGPS data were acquired in Winter, with a more fast changing topography, they provide better validation results than Lidar data (acquired in the middle of the Summer). This is mainly due to the vertical precision of DGPS measurements, inferior to 10 cm, that is better than the precision of Lidar measurements (about 20 cm).
This suggests that RMS error in Summer in well short of 50cm, probably inferior to 30cm.