Pulse-Compression Radar with Doppler Processing and Two-Plane Monopulse Localization Using ADALM-PLUTO

Abstract

This paper presents the design, implementation, and experimental evaluation of a low-cost pulse-compression radar based on the ADALM-PLUTO software-defined radio platform. The radar operates near 2.4 GHz and transmits 1 ms linear-frequency-modulated chirps with a bandwidth and sampling rate of 30.72 MHz. A modified dual-receive, dual-transmit ADALM-PLUTO provides coherent full-duplex acquisition, while separate patch-antenna arrays form the transmit and receive apertures. The implemented processing chain combines pulse compression, coherent Doppler processing, clutter-map subtraction, CFAR detection, and two-plane monopulse localization using amplitude comparison in elevation and phase comparison in azimuth.

The work addresses practical SDR-radar limitations, including transmit-to-receive leakage, transmitter-induced spurious components, channel-delay mismatch, acquisition-buffer timing offsets, and host-processing latency. Analytical models are developed for the antenna patterns, monopulse response, detection range, and localization accuracy.

Five outdoor experiments involving pedestrian, vehicle, and maritime targets produced dominant detection sequences consistent with the target routes and demonstrated Doppler-based radial-velocity discrimination and qualitative trajectory formation in urban and coastal environments at ranges up to approximately 600 m. Range estimation was generally more stable than cross-range and height estimation, which remained sensitive to multipath propagation, calibration errors, and angular-estimation uncertainty. The platform and accompanying open-source implementation provide an accessible framework for studying pulse compression, Doppler processing, monopulse localization, and low-cost SDR-based radar systems.