Processing method base on synthetic spectrum using stepped-frequency chirps

To decrease the influence of echo envelop migration in one-dimension high range resolution profile and depress the side-lobe of the profile, an improved signal processing schemes for stepped-frequency chirps is proposed. It assumed the stepped-frequency chirps as a chirp signal with large bandwidth, but was transmitted and received separately by several times. After synthesizing spectrum of each sub-pulse in frequency domain, high range resolution profile could be achieved through the matched filter. Compared to the classical method, it has advantages such as without range unambiguous, lower sidelobes level in the range profile and convenient motion compensation.