A Doppler light detection and ranging, LIDAR, system mounted on a vehicle, the LIDAR system comprising: a laser source configured to emit an optical signal; a modulator configured to modulate a phase or a frequency of the optical signal; one or more scanning optics configured to transmit the modulated optical signal; and a processing system configured to: construct a scene comprising a three-dimensional, 3D, point cloud with relative Doppler speed between each point and the LIDAR system as a result of one scan, wherein the 3D point cloud corresponds to a return signal received responsive to the transmitted optical signal, wherein the return signal is scattered from an object that is moving or not moving; determine a speed and a direction of one or more moving objects by analyzing scene data; wherein the processing system is characterized in that it is further configured to: receive returns from spots (591, 592) different distances ahead on a road surface in response to scanning beams at different inclination angles; be operated to collect the 3D point cloud that indicates for each point an inclination angle and the relative Doppler speed between the point and the LIDAR system; identify in the 3D point cloud multiple stationary points corresponding to the spots th based on the inclination angle for each point; determine a ground speed of the vehicle based on multiple relative Doppler speeds corresponding to the multiple stationary points; and control the vehicle responsive to the ground speed of the vehicle and a position of the vehicle. a laser source configured to emit an optical signal; a modulator configured to modulate a phase or a frequency of the optical signal; one or more scanning optics configured to transmit the modulated optical signal; and a processing system configured to: construct a scene comprising a three-dimensional, 3D, point cloud with relative Doppler speed between each point and the LIDAR system as a result of one scan, wherein the 3D point cloud corresponds to a return signal received responsive to the transmitted optical signal, wherein the return signal is scattered from an object that is moving or not moving; determine a speed and a direction of one or more moving objects by analyzing scene data; wherein the processing system is characterized in that it is further configured to: receive returns from spots (591, 592) different distances ahead on a road surface in response to scanning beams at different inclination angles; be operated to collect the 3D point cloud that indicates for each point an inclination angle and the relative Doppler speed between the point and the LIDAR system; identify in the 3D point cloud multiple stationary points corresponding to the spots th based on the inclination angle for each point; determine a ground speed of the vehicle based on multiple relative Doppler speeds corresponding to the multiple stationary points; and control the vehicle responsive to the ground speed of the vehicle and a position of the vehicle. construct a scene comprising a three-dimensional, 3D, point cloud with relative Doppler speed between each point and the LIDAR system as a result of one scan, wherein the 3D point cloud corresponds to a return signal received responsive to the transmitted optical signal, wherein the return signal is scattered from an object that is moving or not moving; determine a speed and a direction of one or more moving objects by analyzing scene data; wherein the processing system is characterized in that it is further configured to: receive returns from spots (591, 592) different distances ahead on a road surface in response to scanning beams at different inclination angles; be operated to collect the 3D point cloud that indicates for each point an inclination angle and the relative Doppler speed between the point and the LIDAR system; identify in the 3D point cloud multiple stationary points corresponding to the spots th based on the inclination angle for each point; determine a ground speed of the vehicle based on multiple relative Doppler speeds corresponding to the multiple stationary points; and control the vehicle responsive to the ground speed of the vehicle and a position of the vehicle. receive returns from spots (591, 592) different distances ahead on a road surface in response to scanning beams at different inclination angles; be operated to collect the 3D point cloud that indicates for each point an inclination angle and the relative Doppler speed between the point and the LIDAR system; identify in the 3D point cloud multiple stationary points corresponding to the spots th based on the inclination angle for each point; determine a ground speed of the vehicle based on multiple relative Doppler speeds corresponding to the multiple stationary points; and control the vehicle responsive to the ground speed of the vehicle and a position of the vehicle.