Ground Control Points (GCPs) of tidal flats at Port Fourchon-Louisiana-USA with longitude, latitude, elevation and differences (m) between latitudes longitudes and elevation obtained in Oct/2017, Mar/2018, Nov/2018, Nov/2019, Nov/2021 and Jul/2022 by aerophotogrammetry from a DJI Phantom 4 Advanced and RTK drone and those obtained in the field by a Trimble Catalyst receiver, supported by a differential Global Navigation Satellite System with a millimetric correction (precision ± 2 cm) and an electronic Self Leveling Horizontal Rotary Laser (precision ± 2 cm). These data were used to evaluate the digital elevation model (DEM) acquired by photogrammetry. The vertical differences between GCPs and the DEM were evaluated by equation Zdif = ZDEM - Zgrd, where Zdif = the vertical differences, ZDEM = the Z value of the DEM, and Zgrd = the Z value of the GCPs.