Altitude Measurement and Tracking Algorithm for FMCW Radar Altimeter Based on Reconfigurable Baseband waveform

Abstract

An altitude measurement and tracking algorithm for Frequency Modulated Continuous Wave (FMCW) Radar Altimeter making use of variable Sweep Rate has been presented in this paper. To enable on the fly real-time reconfiguration of the baseband FMCW signal parameters, a Direct Digital Synthesizer (DDS) based scheme has been used which ensures the generation of baseband waveform with different Sweep Rates for different altitude zones. The proposed scheme of Altitude Measurement & Tracking Algorithm is aimed at reducing the bandwidth of the beat frequency signal specifically for the applications requiring wide range of altitude to be measured which in turn leads to reduction of thermal noise floor and better sensitivity. In addition, it also ensures the reliable detection of beat frequency corresponding to the ground return signal in the presence of in-band spurious signals generated from power supply circuit.