Deep detection of large depth radar ultra PE in Zhengzhou, Henan Province
Current situation of urban underground space exploration
For a long time, the detection method of urban underground space has been limited by methods and instruments, and has been unable to detect the effect of people's needs. For example, the pipeline detector can only detect metal pipes, and the detection depth is generally no more than two meters. The detection depth of micro motion method is large, but the measurement efficiency is low and the detection accuracy is poor. The effect of small point spacing of high-density resistivity imaging method is good, but it is often difficult to construct due to the limitation of site conditions. Ground penetrating radar has attracted our attention because of its non-destructive and high-precision characteristics. However, the radar wave is rapidly attenuated by the characteristics of the propagation medium. The application of traditional GPR in cities is often used in pipeline detection and cavity detection within 3 meters.
Current urban underground space construction
With the pace of urban development, the depth of about 3 meters has been unable to meet the needs of urban construction. Therefore, Canadian Sensors & software company launched a new generation of large depth ground penetrating radar at the end of 2018. Due to the following advantages, the detection depth of this radar is at least twice that of the previous generation.
1. The maximum emission voltage is 1000V, and a deeper signal can be obtained only with greater excitation
2. Higher sensitivity 1.5 μ 5. Higher sensitivity can capture weaker signals
3. 32-bit data output and high-speed data superposition technology greatly reduce the interference of random noise. The interference level can be reduced by up to 100 times, and the detection depth increases by 3 to 10 times with the local resistivity.
Experiment details
On the 22nd of this month, our company was invited to Henan to carry out the field detection experiment of large depth radar ultra PE. As the experimental site is located on a busy road, this experiment is conducted late at night.
In this experiment, 50MHz and 100MHz low-frequency antennas are selected to measure respectively.
Construction site
Line position
Experimental results
Pictures of field instrument results
Data processing results
Data result oscillogram
It can be clearly seen that the results on the site are basically the same as those on the computer. With the new generation of ultra pulseekko 50MHz antenna and 65536 times of superposition, the subway tunnel with an underground space of about 10m can be effectively distinguished on the site, and the results are clearly visible.
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