Using radar principles to explore the ground has been proposed as early as 1910. At that time, G. Leimbach and H. Lowy of Germany had clarified this issue in the form of patents. In 1926, Hülsenbeck first used pulse technology to determine the location of buried bodies and pointed out that this technology was superior to seismic methods due to the realization of wave source directionality. However, since the underground medium has much stronger electromagnetic wave attenuation characteristics than air, and coupled with the diversity of underground medium conditions, the propagation characteristics of waves in the ground are much more complex than in the air. Therefore, in the next 60 years, pulse technology, as a detection method, was mostly used in media such as ice and salt with weak wave absorption. For example, B.O. Steenson (1951) and S. Evans (1963) used radar to measure the thickness of glaciers and polar ice. Harrison obtained data penetrating 800 to 2200m on the Antarctic ice in 1970. L.T. Procello used radar to study the lunar surface. Structure, R.R. Unterberger detects the thickness of glaciers and icebergs, etc. With the greatly improved signal-to-noise ratio of instruments and the application of data processing technology, the practical application range of ground-penetrating radar has expanded rapidly after the 1970s, including: detection of quarries in limestone areas; detection of freshwater and desert areas; Engineering geological detection; coal mine detection; peat survey; radioactive waste disposal survey; and ground and borehole radar for geological structure mapping, hydrogeological survey, cavity and crack investigation under foundations and roads, buried object detection, dams, tunnels, etc. Exploration of embankments, ancient tomb ruins, etc.
With the rapid development of microelectronics technology, current ground-penetrating radar equipment is being improved from large and bulky structures to lightweight structures suitable for field use.
The development of ground-penetrating radar instruments in my country began in the early 1970s. The Geophysical Exploration Institute of the Ministry of Geology and Mineral Resources, the Coal Research Institute of the Ministry of Coal, as well as some universities and other research departments have all conducted the development of ground-penetrating radar equipment. and field test work. At that time, a same-point antenna was used, and a high-frequency oscilloscope was used to display the echo, and the first arrival of the reflection was directly read or the waveform was photographed. Due to various reasons, this research could not be formally used in practice. At present, the State Seismological Bureau, hydropower survey and design department, coal department, railway department, relevant departments of the Yellow River Water Conservancy Commission, as well as some engineering survey units and some universities have successively introduced foreign instruments, and the application and theoretical research work of ground penetrating radar have been promoted. Great development.
After China University of Geosciences (Wuhan) introduced ground-penetrating radar equipment from Canada in 1990 using a World Bank loan from the Education Commission, it carried out a series of theoretical and radar data positive and negative studies with funding from the National Natural Science Foundation. performance research, as well as testing and survey work on engineering sites.
The following technical characteristics of ground-penetrating radar pave the way for the rapid expansion of its application fields: ①Ground-penetrating radar is a non-destructive geophysical detection technology that can be safely used in cities. and construction sites under construction. For portable radar equipment, the working site conditions can be arbitrary, the adaptability and resistance to magnetic interference are strong, and it can work in various noisy environments in the city with little impact from environmental interference. ② It has satisfactory detection depth and resolution in engineering geological survey. Some equipment can also provide real-time profile records and map displays with two-dimensional coordinates on site, and the images are clear and intuitive. ③The portable instruments are fully digital on-site raw data collection and recording, and all digital collection, recording, storage, processing, display and graphing are controlled by a general-purpose portable microcomputer. Fully battery powered, low power consumption. The lightweight instrument can be automatically controlled and operated. Only 1 to 2 people can work on site, and the work efficiency is high. Of course, due to the use of a higher operating frequency, the attenuation of electromagnetic wave energy in the underground is greater, so under the condition of high conductivity and thick coverage, the detection depth is limited. Like other geophysical prospecting methods, the correct interpretation and interpretation of ground-penetrating radar images has always been an important and complex task for ground-penetrating radar workers.