The disclosure includes a computer-implemented method for predicting trajectory data of an object including: acquiring radar data of the object; determining a parametrization of the trajectory data of the object based on the radar data; and determining a variance of the trajectory data of the object based on the radar data. The trajectory data of the object includes a position of the object and a direction of the object. The parametrization includes a plurality of parameters and a polynomial of a pre-determined degree. The parameters include a plurality of coefficients related to elements of a basis of the polynomial space of polynomials of the pre-determined degree.