The underground detection system contains a cable micro-vibration detector array. Based on MEMS techniques, the cable micro-vibration detector has made breakthroughs in high-precision and low-noise micro-vibration data, and the high-precision spatial positioning based on carrier phase observation. Its dynamic quality can effectively discover actions of vehicles passing and tunnel digging at night.

The principle of TDR is based on the transmission of signal in a certain transmission medium, such as cable. The TDR equipment injects a high-speed narrow pulse into the cable, and monitors the reflected signal. When the transmission medium changes in impedance, the reflected signal accordingly changes. 

Figure System Sketch Map of Underground TDR Vibration Detection

Characteristics

→  Low construction cost: complex construction is needless.

→  High positioning accuracy: the positioning accuracy is less than 1m.

→  Quick response: the response time is less than 1s, real-time online monitoring is achieved.

Radio Monitoring

Radio monitoring can be used to monitor the wireless signal and detect the suspicious wireless communication activity and illegal band transmitter in a timely manner, which provides an important means of security protection. Effectively, it can discover the wireless signal of remote aircraft control, interphone and cluster communication system, perform identification and pre-warning against illegal signals, and provide the discovery and pre-warning in the electromagnetic space dimensionality. 

It can be used in conjunction with radar and frequencyspectrumcontrol equipment. The electromagnetic spectrum management and control system can be built by distributed interference direction monitoring, as shown in the figure below:

Figure Multi-Mode Distributed Radio Monitoring System

Figure Radio Detection and Analysis Interface