For widespread adoption, public security and surveillance systems must be accurate, portable, compact, and real-time, without impeding the privacy of the individuals being observed. Current systems broadly fall into two categories -- image-based which are accurate, but lack privacy, and RF signal-based, which preserve privacy but lack portability, compactness and accuracy. Our paper proposes mmSense, an end-to-end portable miniaturised real-time system that can accurately detect the presence of concealed metallic objects on persons in a discrete, privacy-preserving modality. mmSense features millimeter wave radar technology, provided by Google's Soli sensor for its data acquisition, and TransDope, our real-time neural network, capable of processing a single radar data frame in 19 ms. mmSense achieves high recognition rates on a diverse set of challenging scenes while running on standard laptop hardware, demonstrating a significant advancement towards creating portable, cost-effective real-time radar based surveillance systems.

翻译：为了实现广泛部署，公共安全与监控系统必须在精准、便携、紧凑且实时的同时，不侵犯被观察者的隐私。现有系统大致分为两类——基于图像的方案虽精准但缺乏隐私保护，而基于射频信号的方案虽保护隐私却难兼顾便携性、紧凑性和准确性。本文提出mmSense——一种端到端便携式微型化实时系统，能够以离散且保护隐私的方式精准探测人体上隐藏的金属物体。mmSense采用毫米波雷达技术，通过Google的Soli传感器进行数据采集，并配备我们的实时神经网络TransDope，可在19毫秒内处理单个雷达数据帧。mmSense在多种具有挑战性的场景中实现了高识别率，且运行于标准笔记本电脑硬件之上，为构建便携、经济高效的实时雷达监控系统迈出了重要一步。