SOLUTION

Large depth exploration

Cave detection

Hollow road surface

Highway inspection

Tunnel lining

Disaster emergency response

Slope monitoring

Reservoir monitoring

Flash flood discharge

Structural defects

Geological karst cave

Tunnel leakage (water-rich) detection

Related plans：

1. Radar Detection Principle

Ground Penetrating Radar (GPR) works by using high-speed, carrier-free pulses as the signal source for detecting underground targets. Pulse parameters are determined by the target detection requirements. A wideband antenna converts the high-speed pulses into pulsed electromagnetic waves for radiation. A portion reaches the receiving antenna directly through the transmitting antenna, forming a direct wave that can be used as a reference for the depth of the underground target; another portion propagates underground. When encountering underground targets or different medium interfaces, reflections occur. The reflected electromagnetic waves form reflected waves from the ground surface to the receiving antenna. The time difference between the reflected wave and the direct wave reflected from the ground surface is the time it takes for the electromagnetic wave to travel from the ground surface to the target and back to the ground surface. If the speed of electromagnetic wave propagation underground is known, the depth of the underground target or interface can be determined. Furthermore, the reflected waves carry information about the properties of the underground target and medium. By analyzing the reflected waves, the nature of the underground target can be determined. When the transmitting and receiving antennas are in a fixed relative position on the ground surface and move together, a set of reflected waves can be obtained. Displaying this set of reflected waves reveals the relative position of the underground target to the ground surface, thus locating the target. Because the path, intensity, and waveform of electromagnetic waves change as they propagate through media with different electrical properties and morphologies, the structure and depth of the medium can be determined based on the measured propagation time, amplitude, and waveform of the wave. The radar image shows the pulsed reflected waveform, with positive and negative peaks distinguished by white and black. The in-phase axis visually represents the reflecting surface of the underground target.

Ground penetrating radar determines the distribution and presence of underground targets by using the underground electromagnetic parameters carried by the radiation, scattering, and reflection of pulsed electromagnetic waves. Detecting underground targets essentially involves measuring underground electromagnetic parameters.

2. Antenna Frequency

Steel Bar Detection Data

Layered Detection Data

3. Application Scenarios

4. Important Parameters

Dielectric Constant: Describes the ability of a material to store and release electromagnetic energy. It is usually expressed as a dimensionless relative dielectric constant, where:

Relative Dielectric Constant Table

Reflection Coefficient:

The intensity of the reflected signal mainly depends on the electrical difference between the upper and lower layers of the medium; the greater the electrical difference, the stronger the reflected signal. The larger the difference in electromagnetic properties between the media on both sides of the interface, the stronger the reflected wave and the greater the reflection amplitude. The nature of the media on both sides can be determined from the reflection amplitude.

Polarity of the reflected wave: When a wave travels from a medium with a lower dielectric constant to a medium with a higher dielectric constant, the reflection coefficient is negative, i.e., the reflected wave amplitude is reversed, and the reflected wave is opposite to the incident wave; when traveling from a slower to a faster medium, the reflected wave amplitude is in the same direction as the incident wave.

1. Based on the amplitude and polarity, underground anomalies can be determined as voids or water-rich areas;

2. Water has a high relative dielectric constant and strong absorption capacity for electromagnetic waves. The overall determination can be made based on the signals around and at the bottom of the anomaly (multiple reflections).