Holography of Wi-Fi radiation

TL;DR

This paper introduces a method to record and digitally reconstruct holograms of Wi-Fi electromagnetic waves, enabling 3D imaging of objects within a meter-sized region with improved image quality.

Contribution

It presents a novel scheme for phase-coherent hologram recording of Wi-Fi radiation over large areas and demonstrates 3D object reconstruction using digital algorithms.

Findings

Successful 3D imaging of objects using Wi-Fi holography

Enhanced image quality with dark field propagation techniques

Digital reconstruction enables detailed visualization of the scene

Abstract

Wireless data transmission systems such as WiFi or Bluetooth emit coherent light - electromagnetic waves with precisely known amplitude and phase. Propagating in space, this radiation forms a hologram - a two-dimensional wavefront encoding a three-dimensional view of all objects traversed by the light beam. Here we demonstrate a scheme to record this hologram in a phase-coherent fashion across a meter-sized imaging region. We recover three-dimensional views of objects and emitters by feeding the resulting data into digital reconstruction algorithms. Employing a digital implementation of dark field propagation to suppress multipath reflection we significantly enhance the quality of the resulting images.