Shui Hanyue, Geng Haoran, Li Qiong, Du Li, Du Yuan
School of Electronic Science and Engineering, Nanjing University, Nanjing 210001, China.
Sensors (Basel). 2022 Feb 6;22(3):1236. doi: 10.3390/s22031236.
The method of making precise measurements of remote water depth using mmWave technology has great potential for preventing urban waterlogging. To achieve waterlogging prevention, the mmWave system needs to measure the water depth change accurately with a short acquisition time. This paper demonstrates a new accurate mmWave water depth measurement system based on Frequency Modulated Continuous Wave (FMCW) Radar with a center frequency of 77 GHz. To improve distance resolution and lower acquisition time, the Swept Frequency-Cross Correlation (SFCC) algorithm is proposed for the first time to improve the distance computation resolution by 9× and lower time complexity from O(n·logn) to O(n) compared to traditional FFT-based FMCW radar distance computation. A prototype system equipped with a humidity sensor, a processor module and TI's FMCW radar module is designed for monitoring urban floods in cities. Using the prototype system with the proposed SFCC, the depth measurement error is reduced from 4.5 cm to less than 5 mm, compared to the default radar post-processing algorithm embedded in the radar module.
利用毫米波技术精确测量远程水深的方法在预防城市内涝方面具有巨大潜力。为实现内涝预防，毫米波系统需要在短采集时间内准确测量水深变化。本文展示了一种基于中心频率为77GHz的调频连续波（FMCW）雷达的新型精确毫米波水深测量系统。为提高距离分辨率并缩短采集时间，首次提出扫频互相关（SFCC）算法，与传统基于快速傅里叶变换（FFT）的FMCW雷达距离计算相比，将距离计算分辨率提高9倍，时间复杂度从O(n·logn)降低到O(n)。设计了一个配备湿度传感器、处理器模块和德州仪器FMCW雷达模块的原型系统，用于监测城市中的洪水。与雷达模块中嵌入的默认雷达后处理算法相比，使用配备所提出的SFCC的原型系统，深度测量误差从4.5厘米降低到小于5毫米。
