Radar method for measuring distances between and relative speeds of a vehicle and one or more obstacles

Abstract

The present invention relates to a CW radar method for measuring distances between and relative speeds of a vehicle and one or more obstacles. The present invention further provides that the transmission (s(t)) can be composed of at least four consecutive chirps (A, B, C, D), each having different slopes. The intersection points of all lines in the distance-relative speed diagram from two chirps (A, B) can be calculated from all the ascertained frequency positions K and K . To validate those intersection points, one may observe whether a peak exists in the Fourier spectrum of a third chirp C at a frequency position K , whose assigned line intersects a surrounding area of the intersection point in the distance-relative speed diagram. A further validation of those intersection points involves observing whether a peak exists in the Fourier spectrum of a fourth chirp D at a frequency position K , whose assigned line intersects a surrounding area of the intersection point in the distance-relative speed diagram. The intersection points are then regarded as valid, when they satisfy both conditions.