Large-burial-depth ground penetrating radar system supporting multi-path data acquisition

Abstract

The invention discloses a large-burial-depth ground penetrating radar system supporting multi-path data acquisition. The system comprises a real-time sampling master control system, a multi-time backboard system, an array antenna system, an accurate positioning unit and an upper computer. According to the invention, deep target area signal energy is actively enhanced through a multi-receiving focusing mode, multi-dimensional scattering information of a target body is acquired by using a multi-path mode, and multi-path data is subjected to cooperative processing through system data superposition. The problems that when a traditional ground penetrating radar detects a large-burial-depth target, signal attenuation is fast, the signal-to-noise ratio is low, the resolution and the penetration depth are contradictory, and the multiplicity of an inversion result is high are effectively solved, and the penetrating power of deep detection, the imaging resolution and the reliability of geological interpretation are remarkably improved.

Description

Technical Field

[0001] This invention relates to the field of ground-penetrating radar (GPR) detection technology, and more particularly to a deep-buried GPR system that supports multipath data acquisition. By acquiring and processing echo signals with multi-phase information, it achieves the acquisition of information on the multipath propagation of electromagnetic waves in underground media. Combined with multipath data superposition, the detection depth of the GPR is significantly improved. Background Technology

[0002] Ground penetrating radar (GPR) is a geophysical method that utilizes the reflection and scattering phenomena of electromagnetic waves at points where the electromagnetic properties of underground media change to acquire information about underground scenes. It can achieve efficient and non-destructive detection of underground targets. With the in-depth development of GPR research, the detection task has evolved from simply acquiring information such as the location, shape, and size of targets to accurately inverting the structural characteristics of targets buried at great depths.

[0003] For the detection of deep-buried targets, traditional ground-penetrating radar systems face severe challenges: (1) Severe signal attenuation: Electromagnetic waves attenuate exponentially with propagation distance, resulting in extremely weak signals and low signal-to-noise ratio at depth. (2) Contradiction between resolution and detection depth: High-frequency antennas are required to improve resolution, but high-frequency signals attenuate faster; low-frequency antennas are required to increase detection depth, but resolution will decrease. (3) Limited information from a single acquisition path: Traditional systems typically use a single transmit-receive path. For complex deep structures, the inversion interpretation of a single dataset is subject to multiple solutions, resulting in insufficient accuracy and reliability. (4) Weak anti-interference capability: Weak signals at depth are easily submerged by environmental noise and system noise.

[0004] While existing technologies employ array antennas or multi-channel systems to increase spatial sampling density, they primarily focus on shallow, high-resolution imaging. Their system architecture, signal excitation, and processing methods are not suitable for enhancing and extracting extremely weak signals in deep-buried exploration. How to synergistically improve the penetration capability, resolution, and interpretation reliability of deep-buried exploration is a pressing issue that needs to be addressed in this field. Summary of the Invention

[0005] The purpose of this invention is to overcome the shortcomings of existing technologies and provide a deep-penetrating radar system that supports multi-path data acquisition. This system, through innovative hardware architecture and collaborative data overlay processing, effectively enhances deep signal energy and comprehensively utilizes multi-dimensional information to achieve high signal-to-noise ratio, high resolution, and high reliability detection and imaging of deep-penetrating targets.

[0006] The technical solution of the present invention is as follows: a deep-buried ground-penetrating radar system that supports multi-path data acquisition, the system comprising a real-time sampling main control system, a multi-path backplane system, an array antenna system, a precise positioning unit and a host computer.

[0007] Furthermore, the real-time sampling control system includes an FPGA, a high-speed AD converter, and circuitry. It directly samples the echo signal, obtaining N sampling points for each echo. Through multiple transmission cycles, it controls the stepping relationship between transmission and sampling, and the obtained data is stitched together to obtain a complete echo waveform.

[0008] Furthermore, the circuit includes a transmit pulse generation circuit, an echo signal receiving multiplexing circuit, a clock management circuit, and a ranging wheel interface circuit.

[0009] Furthermore, the multiple backplane system adopts a multi-transmit and multi-receive working mode, and reliably connects with the real-time sampling main control system through the SMB interface to realize the access of multiple echo signals.

[0010] Furthermore, the functions of the multiple backplane system include echo signal input and switching, transmit pulse conditioning, and a high-voltage power supply module.

[0011] Furthermore, the echo signal input and switching, and the transmit pulse processing are integrated into an echo signal from the antenna to the AD converter. A multiplexer is integrated on the backplane to realize the acquisition of multiple received signals.

[0012] Furthermore, the high-voltage power supply module is a single high-voltage power supply.

[0013] Furthermore, the array antenna system adopts a modular design, consisting of a transmitting antenna and multiple receiving antennas.

[0014] Furthermore, the modular design connects each antenna module to the main control subsystem and the data acquisition subsystem via cables, and power and signals are transferred through the wiring subsystem within the antenna subsystem.

[0015] Furthermore, the array antenna system includes a transmitting front-end, a pulse source, a transmitting antenna, a receiving antenna, and a low-noise amplifier.

[0016] Furthermore, the array system is responsible for generating and transmitting pulse signals, and receiving and amplifying echo signals.

[0017] Furthermore, the data superposition utilizes electromagnetic wave velocity information to perform time difference correction and in-phase addition of multipath data, thereby improving the detection depth.

[0018] This invention provides a deep-penetrating ground radar system that supports multi-path data acquisition. By acquiring and overlaying multi-path data, it can adapt to the detection needs under different depths and complex geological conditions, improving detection accuracy and depth. Compared with existing technologies, the beneficial effects of this project are:

[0019] (1) Enhance deep signal energy: By using multiple receiving focusing modes and low-frequency high-power transmission, energy is actively concentrated in the deep target area, effectively overcoming the sharp attenuation of signal with distance and significantly improving the signal-to-noise ratio of deep echo.

[0020] (2) Acquiring multi-path information: By using the multi-path acquisition mode, the scattering response of the target body can be obtained from different perspectives, and the amount of information is far greater than that of traditional single-path acquisition.

[0021] (3) Improve resolution and reliability: By using multi-receiver focusing and multi-path data overlay, not only can the horizontal and vertical resolution be improved in a coordinated manner, but the inversion process can also be effectively constrained to obtain a more accurate and reliable underground structure model and reduce the ambiguity of geological interpretation. Attached Figure Description

[0022] Figure 1 Overall design drawing of a deep-buried ground-penetrating radar system to support multi-path data acquisition

[0023] Figure 2 Workflow of a deep-buried ground-penetrating radar system to support multi-path data acquisition

[0024] Figure 3 Diagram of multiple backplane interface relationships

[0025] Figure 4 Overall layout of the antenna system

[0026] Figure 5 Connection relationship between the antenna system and other subsystems Detailed Implementation

[0027] 1. Instrument Connection and Initialization:

[0028] Connect the ground-penetrating radar main unit to the transmitting and receiving antennas via connecting cables, such as... Figure 1 As shown, this ensures the stability and real-time performance of signal transmission.

[0029] The unit is powered on for initialization and establishes a network connection with the host computer.

[0030] Configure the operating parameters of the ground penetrating radar system.

[0031] The radar's operating parameters are received by the real-time sampling main control system.

[0032] The entire ground-penetrating radar system is mounted on a remotely movable vehicle frame.

[0033] 2. Begin measurement:

[0034] After completing the parameter settings, start the measurement.

[0035] In each time-triggered or distance-triggered (analyzing mileage wheel pulse parameters) event, the pulse source of the transmitting unit is synchronously controlled.

[0036] It operates using a polling method, simultaneously collecting echo data from multiple receiving antenna channels.

[0037] Data sets are aggregated according to a multi-channel data organization method.

[0038] Data is transmitted to the host computer via the network port.

[0039] 3. Real-time display and adjustment:

[0040] The host computer displays the detection results in real time, including profile images and signal waveforms of the underground medium.

[0041] The host computer has a built-in professional two-dimensional data processing module, which allows users to flexibly configure parameters on the data processing pages of different channels, and provides a channel switching function to compare the processing effect in real time.

[0042] Initial correction: Zero-point correction is performed on the propagation time of radar waves to eliminate time errors caused by factors such as antenna delay and cable transmission, ensuring the accuracy of depth measurement.

[0043] DEWOW (zero drift removal): Effectively removes low-frequency DC drift components (WOW effect) from the data and restores the true baseline of the signal, which is an important prerequisite for subsequent high-frequency signal analysis.

[0044] Background removal: By calculating and subtracting the gather average or a specified reference background trace, random interference and inherent system noise that appear as horizontal stripes on the profile are effectively suppressed, highlighting effective tilt or anomalous reflection signals.

[0045] Gain: Provides various gain adjustment functions (such as automatic gain, exponential gain, etc.) to compensate for the spherical diffusion and medium absorption attenuation of ground-penetrating radar waves underground, enhance the display energy of deep weak reflection layers, and make the energy distribution of the entire profile more balanced, which is easier to interpret.

[0046] Users can flexibly configure processing parameters and preview the effects in real time, quickly improving the data signal-to-noise ratio and highlighting the target's reflection characteristics.

[0047] 4. Data storage:

[0048] The detection data is saved to the host computer's built-in memory.

[0049] 5. Data Processing:

[0050] Time difference correction for multipath data: Based on the speed of electromagnetic waves, time difference correction is performed on multipath data.

[0051] （1）

[0052] in, The depth of the reflective interface; The speed at which electromagnetic waves propagate; For the first Offset distance during channel signal detection; This is the two-way travel time of the reflected wave; Two-way travel time with zero offset.

[0053] The corrected multipath data is then overlaid:

[0054] （2）

[0055] Matters not covered in this invention are common knowledge.

[0056] The above embodiments are only for illustrating the technical concept and features of the present invention, and are intended to enable those skilled in the art to understand the content of the present invention and implement it accordingly. They should not be construed as limiting the scope of protection of the present invention. All equivalent changes or modifications made in accordance with the spirit and essence of the present invention should be covered within the scope of protection of the present invention.

Claims

1. A deep-penetrating ground radar system supporting multi-path data acquisition, characterized in that: Through innovative hardware architecture and collaborative data overlay processing, the energy of deep signals is effectively enhanced, and multi-dimensional information is comprehensively utilized to achieve high signal-to-noise ratio, high resolution, and high reliability detection and imaging of deep-buried targets.

2. The hardware architecture according to claim 1 includes: It consists of a real-time sampling main control system, a multi-stage backplane system, an array antenna system, a precise positioning unit, and a host computer.

3. The real-time sampling main control system according to claim 2 includes an FPGA, a high-speed AD converter, a transmit pulse generation circuit, an echo signal receiving multiplexing circuit, a clock management circuit, and a ranging wheel interface circuit.

4. The multiple backplane system echo signal input and switching, transmit pulse conditioning, and high-voltage power supply module as described in claim 2. The echo signal input, switching, and transmission pulse processing are combined into an echo signal that travels from the antenna to the AD converter. A multiplexer is integrated on the backplane to achieve multi-channel signal acquisition.

5. The array antenna system according to claim 2 adopts a modular design, consisting of one transmitting antenna and multiple receiving antennas. In this modular design, each antenna module is connected to the main control subsystem and the data acquisition subsystem via cables. Power and signals are transferred through wiring terminals within the antenna subsystem. The array antenna system includes a transmitting front-end, a pulse source, a transmitting antenna, receiving antennas, and a low-noise amplifier.

6. The data overlay processing according to claim 1 includes data preprocessing such as gain recovery, background denoising, and frequency domain filtering for each path data, and using electromagnetic wave velocity information to perform time difference correction and in-phase addition of multi-path data to improve detection depth.

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