weighted residuals from equation 16 is minimum thereby assuring that the corresponding value of u03c8 was the proper and optimum choice and divorced of any dependency upon output history the rotational velocities w yy and w sub zz so obtained are stored in coordinate computer 27 as are aperture weighting range frequency azimuth and elevation angles for all scatterers above a prescribed signal threshold after a prescribed period of such data collection i e 6 seconds a third degree weighted least squares polynomial curve fit as denoted by equation 29 is performed on the collected w yy and w zz data in coordinate computer 27 response frequencies are determined using an interpolation routine carried out in coordinate computer 27 followed by scatterer sorting and precision frequency determination using third degree polynomial curve fits similar in form to equation 29 scatterer acceleration is derived from differentiating the frequency polynomial in coordinate computer 27 sorted azimuth and elevation angle data is similarly curve fitted in coordinate computer 27 in accordance with equation 32 as is the elevation angle time derivative as prescribed by equation 33 for a number of the brightest scatterers i e 10 equation 31 is applied in coordinate computer 27 for each of the 10 scatterers and an averaged w los is derived therefrom the time derivatives w yy and w zz are computed by equation 30 and.