Velocity Measurements from a Self-Propelled Vehicle

Velocity measurements from a self-propelled vehi- cle are limited by the vehicle´s response to the ambient velocity field. For constant thrust and depth a linear model predicts that the vehicle acquires a fraction 1/e of an impulsive incremental longitudinal velocity change in a distance λ_L = [l(1 + C_M)]/C_D where ℓ is the length of the vehicle, C_M is the added mass coefficient, and C_D is the drag coefficient. For a small velocity increment normal to the vehicle path, the model predicts a response length λ_T = 2λ_L.