한국도로학회논문집 제20권 제6호 (p.101-108)

도로공동 탐지를 위한 멀티채널 GPR 장비 비교 연구

Comparison of Multichannel Ground Penetrating Radar Equipment for Detecting Road Cavities
키워드 :
Road Cavity,Ground Penetrating Radar,Multichannel,Signal analysis

목차

ABSTRACT
1. 서론
2. GPR 탐사 기본 원리
  2.1. GPR 탐사 개요
  2.2. 멀티채널 GPR 탐사 원리
3. 3D 멀티채널 GPR 장비 비교
  3.1. 개요
  3.2. 시험방법
  3.3. 자료처리
4. 멀티채널 GPR 원시 자료 분석 결과
  4.1. 시간 영역 분석
  4.2. 주파수 영역 분석
5. 멀티채널 GPR 자료처리 분석 결과
  5.1. 최적 자료처리 방법
  5.2. 공동 신호분석
6. 결론
REFERENCES

초록

PURPOSES: The purpose of this study is to compare the advantages and disadvantages of 3D multichannel ground penetrating radar (GPR) equipment, which is mainly used for road cavity detection. The optimal signal analysis method was also proposed for 3D GPR data.
METHODS: Four types of 3D GPR equipment were used to detect road cavities in a pilot road section in Seoul. The obtained GPR signals were evaluated in the time and frequency domain using raw data. In addition, various types of filters were applied to time domain (B-scan) data to examine the optimal signal processing.
RESULTS: The time and frequency domain analysis of raw data showed that all the equipment produced reverse and strong signal reflections owing to the low dielectric permittivity of air in the cavity compared with neighbor materials. Also, the asymmetric parabolic curve was observed as well. The optimal signal processing method was determined to detect road cavities: zero-setting and background removal should be applied to all equipment. Bandpass filtering can be optionally applied to remove high-frequency noise or direct waves.
CONCLUSIONS: Despite the different specifications of GPR equipment in terms of signal generation and bandwidth, the GPR signals were appropriate in terms of zero-setting, noise level, and depth of investigation. Therefore, all the multichannel GPR devices evaluated were found to be suitable to detect road cavities located at depths of 1.0 and 1.5 m after the application of proper filtering process.