Study of High-Precision Altimetry Arithmetic in LFMCW Radar System

Introducing a LFMCW (linear frequency modulated continuous wave) radar altimeter system, which is modulating by the triangular wave, is a continuous wave modulation system of access to distance information through modulating the continuous wave. Comparing with the pulse radar, LFMCW radar has many advantages. It is based on the principle of electromagnetic wave propagation delay time in space to determine the height of the Earth´s surface craft. a new arithmetic of processing the echo signal is put forward, in order to achieve the high precision altimetry and target detection and ensure the steady false alarm. The arithmetic adopts the manner of accumulating average through the sliding window, making use of the Doppler frequency shift. Through the echo signal is demodulated and collected and processed, the information of speed and distance is picked up and the false and lose alarm are eliminated when the altitude and the speed are measured in the radar altimetry system.