Abstract
This paper presents the theoretical foundation and computational modeling of a novel phase-based interferometric method for precise displacement estimation in environmental monitoring applications. The method leverages the phase difference between two coherent radio signals transmitted over a wireless forward link, enabling sub-millimeter resolution without relying on reflected signals or embedded sensors. Unlike radar interferometry and distributed fiber optic systems, the proposed technique operates entirely in a forward-link architecture, making it more scalable, energy-efficient, and suitable for low-infrastructure deployments. Special attention is given to the computational procedures required for real-time signal interpretation, including instantaneous phase extraction using the Hilbert transform, phase unwrapping algorithms, and noise mitigation via digital filters. Simulation results confirm that the method is theoretically robust and computationally tractable, offering a practical path toward implementation using lightweight embedded platforms such as software-defined radios (SDRs) with GPS-disciplined oscillators. The results also demonstrate how design parameters such as carrier frequency and dual-tone spacing – affect the sensitivity and resolution of displacement estimates. This study lies at the intersection of applied computer science, signal processing, and geospatial engineering. It provides both a mathematical and algorithmic foundation for future systems aimed at distributed, real-time sensing in civil infrastructure and geohazard management.