The advantage of bistatic remote sensing is the ability to measure in a remote area from the receiver and transmitter. In this case, the scattering will remain quasi-specular and is calculated in the Kirchhoff approximation. This makes it possible to obtain an explicit relationship between the scattering characteristics and the parameters of the water surface, which opens possibilities for creating new algorithms for solving the inverse problem of retrieving wave parameters. In addition, the power of the received signal in the quasi-specular reflection region significantly exceeds the power of the reflected signal in the resonant scattering region, which makes it possible to use the signals of satellite navigation systems reflected from the underlying surface for remote sensing tasks. In this work, a formula is given for the Doppler spectrum (DS) of radiation reflected by a water surface in a bistatic formulation of the problem, taking into account the antenna patterns of the receiving and transmitting antennas, taking into account the movement of the receiver and transmitter. A feature of the approach used is the description of the water surface by six second-order statistical moments. The features of the DS model are investigated depending on the geometry of the problem, on the speeds of the transmitter, and on the direction of the wave propagation. An algorithm is proposed for determining the direction of wave propagation from measurements of the DS characteristics of reflected radiation.