Method for determining an estimate of the absolute radial speed of radar echoes, covering a certain radar area in subsequent scans of duration T scan wherein it transmits a signal and listens to return echoes during a sweep time interval and comprising a coherent transmitter and receiver, with a coherent oscillator that gives the phase reference, a signal processor, a radar extractor that on the basis of detected echoes, produced by objects close to a waterbody surface or by sea spikes produced by a radar in X-band and with resolution of 5-10 meters or less, extracts plots characterized by range and azimuth, the method being characterized in that it comprises a quantization of the range radar area into a plurality of elementary radar range cells, and the execution of the following steps: A1. Extracting from the radar signal provided by the coherent receiver the phase of all echoes within a single sweep; A2. For each cell, calculating the phase differences Δφ between any two subsequent sweeps within a pre-defined coherent processing interval CPI comprising a multiplicity of subsequent sweeps; A2b. Selecting only the range cells wherein the coherent radar extractor has extracted a plot; A3. For the range cells of step A2b, calculating the instantaneous absolute radial speeds v and radial direction of the echoes, starting from the phase differences of sub-step A2, as v = λ /(4 πT)·Δ φ, wherein the radial direction of the echoes is positive in case of moving away of the object that has caused the echo from the radar and negative in the case of approaching to the radar, λ is the radar operation wavelength, T is the time interval between two subsequent sweeps; A4. For each range cell of step A2b, averaging the values of the absolute radial speeds and directions of the echoes obtained for all the CPIs in sub-step A3, obtaining the radial speeds and radial directions of the corresponding extracted plots; and A5. For each range cell of step A2b, obtaining the radial speeds and radial directions of the corresponding extracted plot as the averages calculated in step A4. A1. Extracting from the radar signal provided by the coherent receiver the phase of all echoes within a single sweep; A2. For each cell, calculating the phase differences Δφ between any two subsequent sweeps within a pre-defined coherent processing interval CPI comprising a multiplicity of subsequent sweeps; A2b. Selecting only the range cells wherein the coherent radar extractor has extracted a plot; A3. For the range cells of step A2b, calculating the instantaneous absolute radial speeds v and radial direction of the echoes, starting from the phase differences of sub-step A2, as v = λ /(4 πT)·Δ φ, wherein the radial direction of the echoes is positive in case of moving away of the object that has caused the echo from the radar and negative in the case of approaching to the radar, λ is the radar operation wavelength, T is the time interval between two subsequent sweeps; A4. For each range cell of step A2b, averaging the values of the absolute radial speeds and directions of the echoes obtained for all the CPIs in sub-step A3, obtaining the radial speeds and radial directions of the corresponding extracted plots; and A5. For each range cell of step A2b, obtaining the radial speeds and radial directions of the corresponding extracted plot as the averages calculated in step A4.