  This research addresses the challenge of executing multi-UAV survey missions
over diverse terrains characterized by varying elevations. The approach
integrates advanced two-dimensional ergodic search technique with model
predictive control of UAV altitude and velocity. Optimization of altitude and
velocity is performed along anticipated UAV ground routes, considering multiple
objectives and constraints. This yields a flight regimen tailored to the
terrain, as well as the motion and sensing characteristics of the UAVs. The
proposed UAV motion control strategy is assessed through simulations of
realistic search missions and actual terrain models. Results demonstrate the
successful integration of model predictive altitude and velocity control with a
two-dimensional potential field-guided ergodic search. Adjusting UAV altitudes
to near-ideal levels facilitates the utilization of sensing ranges, thereby
enhancing the effectiveness of the search. Furthermore, the control algorithm
is capable of real-time computation, encouraging its practical application in
real-world scenarios.
