A method of remote sensing of a body of water comprising: using a radar apparatus installed on a vessel to obtain a plurality of radar intensity images of the surface of the body of water; registering the geographic location of each of the plurality of radar intensity images, wherein each of the plurality of radar intensity images is converted into a geographically-referenced image using position and heading data recorded by a navigation unit, and wherein registering the geographic location of each of the plurality of radar intensity images comprises: applying one or more of the following principal systematic calibration offsets to increase image sharpness: an azimuthal alignment error (α) corresponding to an angular offset between a heading recorded by the navigation unit installed on the vessel and a true heading of the vessel; a start range error (β) corresponding to an error in a distance from an antenna to a data processing unit of the radar apparatus for a first range bin in the plurality of radar intensity images; and/or a system time error (γ) corresponding to a total time delay resulting from a time delay due to communication of data between the radar apparatus and the data processing unit and/or a computer-induced time stamp delay between a true image recording time and an image time-stamp; wherein applying the principal systematic calibration offsets begins in a first pass with all three principal systematic calibration offsets initially set to equal zero and conducting a search for an optimum value of a first one of the three principal systematic calibration offsets; and generating one or more time-integrated images of the surface of the body of water from the geographically-referenced radar intensity images. using a radar apparatus installed on a vessel to obtain a plurality of radar intensity images of the surface of the body of water; registering the geographic location of each of the plurality of radar intensity images, wherein each of the plurality of radar intensity images is converted into a geographically-referenced image using position and heading data recorded by a navigation unit, and wherein registering the geographic location of each of the plurality of radar intensity images comprises: applying one or more of the following principal systematic calibration offsets to increase image sharpness: an azimuthal alignment error (α) corresponding to an angular offset between a heading recorded by the navigation unit installed on the vessel and a true heading of the vessel; a start range error (β) corresponding to an error in a distance from an antenna to a data processing unit of the radar apparatus for a first range bin in the plurality of radar intensity images; and/or a system time error (γ) corresponding to a total time delay resulting from a time delay due to communication of data between the radar apparatus and the data processing unit and/or a computer-induced time stamp delay between a true image recording time and an image time-stamp; wherein applying the principal systematic calibration offsets begins in a first pass with all three principal systematic calibration offsets initially set to equal zero and conducting a search for an optimum value of a first one of the three principal systematic calibration offsets; and an azimuthal alignment error (α) corresponding to an angular offset between a heading recorded by the navigation unit installed on the vessel and a true heading of the vessel; a start range error (β) corresponding to an error in a distance from an antenna to a data processing unit of the radar apparatus for a first range bin in the plurality of radar intensity images; and/or a system time error (γ) corresponding to a total time delay resulting from a time delay due to communication of data between the radar apparatus and the data processing unit and/or a computer-induced time stamp delay between a true image recording time and an image time-stamp; wherein applying the principal systematic calibration offsets begins in a first pass with all three principal systematic calibration offsets initially set to equal zero and conducting a search for an optimum value of a first one of the three principal systematic calibration offsets; and generating one or more time-integrated images of the surface of the body of water from the geographically-referenced radar intensity images.