  In this article, a simplified modeling and system identification procedure
for yaw motion of an unmanned surface vehicle (USV) is presented. Two thrusters
that allow for both speed and direction control propel the USV. The outputs of
the vehicle under inquiry include parameters that define the mobility of the
USV in horizontal plane, such as yaw angle and yaw rate. A linear second order
model is first developed, and the unknown coefficients are then determined
using data from pool trials. Finally, simulations are carried out to verify the
model so that it may be used in a later study to implement various control
algorithms.
