Patent ID: 8305257
Filing Date: 2012-11-06
Classification: G01S,Y02A

Abstract:
1. A method of determining a plurality of wave heights of an ocean wave field comprising: receiving a first real intermediate frequency (IF) radar echo signal, at a first azimuthal radar antenna position, comprised of a plurality of samples, at a marine radar device, as a result of a radar transmit signal first pulse interacting with the ocean wave field; generating a first complex intermediate frequency signal from the first real intermediate (IF) radar echo signal; wherein the first complex intermediate frequency signal is comprised of a plurality of samples, and wherein each sample of the plurality of samples of the first complex intermediate frequency signal has a real part I wherein each sample of the plurality of samples of the first complex intermediate frequency signal corresponds to a range delay, such that there are a plurality of range delays for a corresponding plurality of samples of the first complex intermediate frequency signal; using a computer processor to determine the phase of each sample of the first complex intermediate frequency signal by taking the arc tangent of the ratio of I storing the first plurality of phases for the first complex intermediate frequency signal in computer memory; receiving a second real intermediate frequency (IF) radar echo signal, at a second azimuthal radar antenna position, comprised of a plurality of samples, at the marine radar device, as a result of a radar transmit signal second pulse interacting with the ocean wave field; generating a second complex intermediate frequency signal from the second real intermediate (IF) radar echo signal; wherein the second complex intermediate frequency signal is comprised of a plurality of samples, and wherein each sample of the plurality of samples of the second complex intermediate frequency signal has a real part I wherein each sample of the plurality of samples of the second complex intermediate frequency signal corresponds to a range delay of the plurality of range delays; using a computer processor to determine the phase of each sample of the second complex intermediate frequency signal by taking the arc tangent of the ratio of I storing the second plurality of phases for the second complex intermediate frequency signal in computer memory; using a computer processor to determine the difference between each phase of the first plurality of phases and each phase of the second plurality of phases for a corresponding range delay of the plurality of range delays to determine a plurality of phase differences for the corresponding plurality of range delays; storing the plurality of phase differences in computer memory; wherein there is a time period between the radar transmit signal first pulse and the radar transmit signal second pulse; using a computer processor to transform each of the plurality of phase differences in radians to a Doppler shift of each range delay of the plurality of range delays by dividing each of the plurality of phase differences by the time period between the radar transmit signal first pulse and the radar transmit signal second pulse, so that a plurality of Doppler Shifts are formed one for each range delay of the plurality of range delays; wherein the radar transmit signal first pulse and the radar transmit signal second pulse are part of a radar transmit signal having a wavelength; and using a computer processor to determine a first sequence of a plurality of radial velocity measurements of the ocean wave field from the plurality of Doppler shifts by multiplying each of the plurality of Doppler shifts by one half the wavelength of the first radar transmit signal.