Patent ID: 7928898

Claim:
A method for determining a kinematic state of an object, including at least one of position, velocity and acceleration of the object, said method comprising: a sensor making a sequence of discrete polar measurements with respect to said object, said polar measurements including as polar measurement variables, range and azimuth measurements from said sensor to said object; converting the polar measurements to Cartesian coordinates by conversion of the polar measurement variables range and azimuth; scaling the Cartesian coordinates to Cartesian pseudo-measurements using a scaling factor β which is determined as a function of measured range; determining associated nominal pseudo-measurement error variance matrices, each comprising specific nominal pseudo-measurement error variances (R 2 m ) in a range direction and transversely thereto (C 2 m ), as a function of the measured range; and based on the Cartesian pseudo-measurements and the associated nominal pseudo-measurement error variance matrices, an estimation unit estimating the kinematic state of the object, with an estimated variance {circumflex over (σ)} 2 cross being determined transversely with respect to the range direction; wherein, the scaling factor β is determined in the estimation device such that no systematic error results for a position estimate comprising n>1 measurements; and the nominal pseudo-measurement error variance R 2 m in the range direction is determined in the estimation device as a function of the nominal pseudo-measurement error variance C 2 m transversely to the range direction, or such that the variance {circumflex over (σ)} 2 cross which is estimated after the processing of n>1 measurements, transversely with respect to the range direction, on average matches the actual variance {circumflex over (σ)} 2 cross of the estimated error transversely with respect to the range direction.