Penetration detection method of multi-band modulated wave radar in non-metal medium

Abstract

The invention discloses a penetration detection method of a multi-band modulated wave radar in a non-metal medium. The detection method comprises the following steps: constructing a multi-band hybrid modulated wave radar architecture; the sawtooth wave modulation mode and the triangular wave modulation mode are subjected to alternating or mixed waveform modulation; processing the hybrid modulated wave by adopting a near-field strong clutter suppression algorithm; estimating the distance of the target by adopting a wide-range target rough measurement algorithm; calculating the distance of the target by adopting a short-distance high-precision distance measurement algorithm; performing dynamic compensation on the measurement data by adopting a Kalman filtering state estimation algorithm to obtain a distance estimation result; complementary information of long-wave and short-wave radars is utilized to form a complete detection view. And intelligent collaboration of long and short wave data is realized through hierarchical fusion. Therefore, the system can simultaneously complete large-range transmission type detection and close-range millimeter-level high-precision measurement on one platform.

Description

Technical Field

[0001] This invention relates to the field of penetration detection in non-metallic media, and more particularly to a method for penetration detection in non-metallic media using multi-band modulated wave radar. Background Technology

[0002] In the field of non-metallic medium penetration detection, radar systems face a core performance trade-off. High-frequency short-wave radar (such as millimeter-wave) boasts excellent range resolution due to its ultra-wide bandwidth, making it ideal for precise measurements. However, its electromagnetic waves attenuate rapidly when penetrating media, significantly limiting its detection range. Conversely, low-frequency long-wave radar, with its low frequency and long wavelength, can penetrate media better and achieve long-range detection, but at the cost of a large antenna size and lower resolution. The seemingly contradictory performance indicators of "large range" and "short range (3 cm) and high accuracy (1 mm)" demanded by users cannot be simultaneously met by a single-frequency radar system. Traditional radar design often requires a difficult trade-off between penetration (detection range) and resolution, constituting a fundamental challenge in this technological field. Summary of the Invention

[0003] In view of the above problems, the present invention is proposed to provide a method for penetrating and detecting non-metallic media using multi-band modulated wave radar that overcomes or at least partially solves the above problems.

[0004] According to one aspect of the present invention, a method for penetrating and detecting non-metallic media using a multi-band modulated wave radar is provided, the detection method comprising:

[0005] Constructing a multi-band hybrid modulation wave radar architecture;

[0006] Modulated waveforms that alternate or mix sawtooth and triangular wave modulation modes;

[0007] A near-field strong clutter suppression algorithm is used to process the mixed modulated wave;

[0008] A large-range coarse-measurement algorithm is used to estimate the target's distance;

[0009] The distance to the target is calculated using a short-range, high-precision ranging algorithm;

[0010] The Kalman filter state estimation algorithm is used to dynamically compensate the measurement data to obtain the distance estimation result;

[0011] By utilizing the complementary information from long-wave and short-wave radars, a complete detection view can be formed.

[0012] Optionally, the radar architecture utilizes a flexible software-defined radio (SDR) platform to alternately or hybridize the transmission of electromagnetic waves with different frequencies and modulation schemes, thereby achieving complementary and synergistic performance.

[0013] By combining the penetrating detection capability of long-wave radar with the high-resolution measurement capability of short-wave radar, the system leverages the advantages of each in different operating modes, achieving overall performance that surpasses that of single-band radars.

[0014] Optionally, the modulated waveform that alternates or mixes sawtooth and triangular wave modulation modes specifically includes:

[0015] By leveraging the advantages of both sawtooth and triangular waves, multi-target ranging and velocity measurement can be achieved within one system cycle, while significantly reducing the generation of false targets and lowering the computational load of intermediate frequency signal processing.

[0016] Alternately use sawtooth waves for large-area coarse measurements, and use triangular waves for fine distance and speed measurements.

[0017] Optionally, the process of using a near-field strong clutter suppression algorithm to process the hybrid modulated wave specifically includes:

[0018] Time gating: After the echo signal arrives at the receiving end, a short delay window is set to directly ignore strong clutter from the front surface of the medium and only process the target echo signal that arrives later.

[0019] Frequency domain filtering: Since stationary clutter appears as zero-frequency or low-frequency components in the Doppler spectrum, high-pass filters or band-stop filters are used to remove it in the frequency domain.

[0020] Clutter map adaptive processing: Before detection, a pre-scan is performed on the stationary medium cover to establish a clutter map. During actual detection, the real-time echo data is compared with the clutter map to subtract known clutter components and highlight the target signal.

[0021] Optionally, the method of estimating the target distance using a large-range target coarse measurement algorithm specifically includes:

[0022] Coarse measurements of large-range targets are performed using long-wave radar modes, taking advantage of their strong penetration and long-range detection capabilities.

[0023] Using standard FFT processing, the distance to the target is roughly estimated by identifying peaks in the beat signal spectrum;

[0024] A multi-frequency waveform is used to transmit Chirp waveforms with different repetition periods, and then the interleaved time-delay waveform method is used to solve for the true unambiguous distance and velocity.

[0025] Optionally, the calculation of the target distance using a short-range, high-precision ranging algorithm specifically includes:

[0026] A two-stage algorithm is used for FFT refinement based on super-resolution.

[0027] Phase 1: Utilize the wide bandwidth of the shortwave radar to perform conventional FFT processing to obtain the basic resolution;

[0028] The second stage involves applying more complex super-resolution algorithms to refine the FFT peaks, thereby achieving the precision of the sub-FFT bins.

[0029] High-precision ranging and micro-motion detection based on phase information: For micro-motion within a short distance of 3 cm, the phase information of the demodulated signal is used.

[0030] Optionally, the step of using the Kalman filter state estimation algorithm to dynamically compensate the measurement data and obtain the distance estimation result specifically includes:

[0031] When the hybrid system is working, the Kalman filter state estimation algorithm is used to dynamically compensate the measurement data;

[0032] By fusing radar distance and velocity measurements and combining them with the system's own motion information, the measurement data is corrected and compensated in real time to obtain more accurate and stable distance estimation results.

[0033] Optionally, the process of utilizing complementary information from long-wave and short-wave radars to form a complete detection view specifically includes:

[0034] The fusion of long-wave and short-wave data aims to combine the advantages of both radars to form a complete detection view;

[0035] In the signal layer, raw echo signals from different frequency bands are processed collaboratively to obtain a better signal-to-noise ratio feature layer than a single sensor, fusing key features extracted from long-wave and short-wave radars.

[0036] Based on the detection results of the long-wave radar, decision logic is used to trigger the short-wave radar to enter high-precision mode, and to perform fine measurement on the area locked by the long-wave radar.

[0037] Optionally, the step of triggering the shortwave radar to enter high-precision mode using decision logic based on the detection results of the longwave radar specifically includes:

[0038] A dynamic decision-making logic is constructed, in which the system dynamically adjusts the transmitted waveform, processing algorithm, and fusion strategy according to different working modes and environmental conditions;

[0039] In the close-range high-precision mode, the phase information and super-resolution algorithm of the short-wave radar are used first; in the wide-range scanning mode, the FFT algorithm of the long-wave radar is used.

[0040] This invention provides a method for penetrating and detecting non-metallic media using multi-band modulated wave radar. The method includes: constructing a multi-band hybrid modulated wave radar architecture; alternating or mixing sawtooth and triangular wave modulation modes to generate modulated waveforms; processing the hybrid modulated waves using a near-field strong clutter suppression algorithm; estimating the target range using a large-range target coarse measurement algorithm; calculating the target range using a short-range high-precision ranging algorithm; dynamically compensating the measurement data using a Kalman filter state estimation algorithm to obtain the range estimation result; and forming a complete detection view using complementary information from long-wave and short-wave radars. Intelligent collaboration between long-wave and short-wave data is achieved through hierarchical fusion. This enables the system to simultaneously perform large-range penetrating detection and short-range micrometer-level high-precision measurement on a single platform.

[0041] The above description is merely an overview of the technical solution of the present invention. In order to better understand the technical means of the present invention and to implement it in accordance with the contents of the specification, and in order to make the above and other objects, features and advantages of the present invention more apparent and understandable, specific embodiments of the present invention are described below. Attached Figure Description

[0042] To more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings used in the following description of the embodiments will be briefly introduced. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0043] Figure 1 This is a flowchart of a multi-band modulated wave radar penetration detection method in non-metallic media, provided as an embodiment of the present invention. Detailed Implementation

[0044] Exemplary embodiments of the present disclosure will now be described in more detail with reference to the accompanying drawings. While exemplary embodiments of the present disclosure are shown in the drawings, it should be understood that the present disclosure may be implemented in various forms and should not be limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the disclosure to those skilled in the art.

[0045] The terms "comprising" and "having," and any variations thereof, in the specification, embodiments, claims, and drawings of this invention are intended to cover non-exclusive inclusion, such as including a series of steps or units.

[0046] The technical solution of the present invention will be further described in detail below with reference to the accompanying drawings and embodiments.

[0047] like Figure 1As shown, this invention provides a method for penetrating and detecting non-metallic media using multi-band modulated wave radar. The method includes: constructing a multi-band hybrid modulated wave radar architecture; alternating or mixing sawtooth and triangular wave modulation modes to generate modulated waveforms; processing the hybrid modulated waves using a near-field strong clutter suppression algorithm; estimating the target range using a large-range target coarse measurement algorithm; calculating the target range using a short-range high-precision ranging algorithm; dynamically compensating the measurement data using a Kalman filter state estimation algorithm to obtain the range estimation result; and forming a complete detection view using complementary information from long-wave and short-wave radars.

[0048] This invention proposes a "multi-band hybrid modulation wave radar" architecture. This architecture utilizes flexible platforms such as Software-Defined Radio (SDR) to alternately or hybridize the transmission of electromagnetic waves with different frequencies and modulation methods, achieving complementary and synergistic performance. This approach draws on the successful experience of multi-band collaborative operation in hybrid radar and ground-penetrating radar (GPR). By combining the penetrating detection capability of long-wave radar with the high-resolution measurement capability of short-wave radar, the system leverages the advantages of each in different operating modes, thereby achieving overall performance exceeding that of single-band radars.

[0049] This invention will systematically explain how to construct a radar system that meets users' stringent performance requirements from three levels: physical principles, waveform design, and algorithm implementation. The report focuses on the algorithmic level, detailing the complete processing chain from the raw echo signal to the final high-precision measurement result. This includes near-field clutter suppression, multi-stage ranging algorithms (covering super-resolution technology and high-precision methods based on phase information), and multi-level data fusion strategies, aiming to provide a comprehensive technical blueprint for the development of next-generation penetrating detection systems.

[0050] The fundamental characteristics of long-wave and short-wave radar and the penetration mechanism of non-metallic media include:

[0051] The penetration advantages and limitations of long-wave radar include:

[0052] Long-wave (low-frequency) electromagnetic waves, due to their low frequency and long wavelength, interact weakly with microscopic particles within a medium, resulting in slow energy attenuation. This allows them to propagate over long distances, similar to ground-penetrating radar (GPR), through rocks, soil, ice, and even non-metallic building materials such as wood or ceramics, making them suitable for penetrating detection and large-range measurements. This characteristic of long-wave radar makes it ideal for large-area "reconnaissance" and initial target location. However, wavelength is inversely proportional to resolution; long-wave radar has low range resolution, making it difficult to meet users' 1mm accuracy requirements. Furthermore, the required antenna size is directly proportional to the wavelength, typically necessitating a large antenna, which is unsuitable for portable devices.

[0053] The advantages and limitations of high resolution in shortwave radar include:

[0054] Shortwave (high frequency) radar, especially millimeter-wave radar (30-300GHz), has extremely high frequencies and can achieve ultra-wide bandwidth.

[0055] According to the radar range resolution formula:

[0056] ΔR=2Bc

[0057] Where ΔR is the distance resolution, c is the speed of light, and B is the signal bandwidth. This formula shows that ultra-wide bandwidth is the physical basis for achieving high resolution.

[0058] For example, a 4GHz bandwidth radar can achieve a range resolution of approximately 3.75cm. The high frequency also means that the antenna size can be made very small, facilitating integration into compact devices. However, high-frequency shortwave radiation attenuates rapidly in a medium, has weak penetration, and is easily blocked or significantly weakened by objects. Therefore, its detection range is relatively short, making it unsuitable for long-range penetration detection.

[0059] Electromagnetic wave propagation models in non-metallic media include:

[0060] The behavior of electromagnetic waves penetrating non-metallic media (such as ceramics and wood) can be compared to that of ground-penetrating radar (GPR) detecting underground structures. When an electromagnetic wave encounters an interface between media with different electromagnetic properties (such as dielectric constant and conductivity), some of the energy is reflected back to the radar receiver, while the rest continues to propagate within the medium. The higher the conductivity of the medium, the faster the electromagnetic wave is converted into heat energy during propagation, resulting in a sharp decrease in penetration depth. Understanding this propagation mechanism is the physical basis for designing ground-penetrating radar systems and corresponding algorithms.

[0061] The necessity of a hybrid long-wave and short-wave system includes:

[0062] The user's requirements for "large range" and "high precision (1mm)" are two seemingly contradictory indicators, but the real requirement behind them is not to achieve both of these performances for the same target at the same time.

[0063] Large-range detection can be used for coarse location and penetration confirmation of distant targets, while high-precision detection focuses on fine measurements at close range (3 cm).

[0064] The inherent logic of the long-wave and short-wave hybrid system is as follows: the long-wave radar acts as a "scout," using its strong penetration and long-range detection capabilities to conduct large-scale searches and preliminary target location; while the short-wave radar acts as a "sniper," using its wide bandwidth and high resolution capabilities to perform high-precision measurements in the specific close-range area locked by the long-wave radar.

[0065] The division of labor and cooperation model is the key to resolving performance contradictions and achieving performance complementarity.

[0066] The table below provides a visual comparison of the characteristics of the two radars:

[0067]

[0068]

[0069] Hybrid modulation waveform design and signal processing fundamentals, including:

[0070] The principle of Frequency Modulated Continuous Wave (FMCW) radar is as follows: FMCW radar transmits a continuous signal whose frequency varies linearly with time (commonly referred to as "linear frequency modulation / chirp"). When this signal encounters a target and is reflected back to the radar, due to the propagation time, there will be a frequency difference (i.e., beat frequency) between the received echo signal and the currently transmitted signal. The beat frequency is proportional to the distance to the target. By performing a Fourier transform (FFT) on the beat signal, the range information can be obtained.

[0071] Innovative designs for hybrid modulation waveforms include:

[0072] To address the limitations of traditional modulation waveforms, an innovative scheme that alternates or mixes sawtooth and triangular wave modulation modes has been proposed. This scheme aims to leverage the respective advantages of sawtooth and triangular waves to achieve multi-target ranging and velocity measurement within a single system cycle, while significantly reducing the generation of false targets and lowering the computational load of intermediate frequency signal processing, thereby improving the system's real-time performance. For example, sawtooth waves can be used alternately for large-area coarse measurement, while triangular waves can be used for fine ranging and velocity measurement. This hybrid waveform design not only overcomes the inherent limitations of single waveforms but also provides richer and more reliable raw data for backend algorithms.

[0073]

[0074]

[0075] Key algorithm implementation logic: Large range and high precision ranging

[0076] Near-field strong clutter suppression algorithms include:

[0077] In penetrating detection at extremely short ranges (3 cm), the greatest challenge lies in effectively suppressing strong reflective clutter from ceramic or wooden surfaces. This primary clutter typically has energy far exceeding the weak echoes from targets behind the medium; without processing, the target signal will be completely drowned out. The approach to solving this problem is similar to the logic of suppressing strong reflective clutter at the air-to-ground interface in ground-penetrating radar (GPR).

[0078] The main implementation logic includes:

[0079] Time gating: After the echo signal arrives at the receiving end, a short delay window is set to directly ignore strong clutter from the front surface of the medium and only process the target echo signal that arrives later.

[0080] Frequency domain filtering: Since stationary clutter (such as the surface of a medium) appears as zero-frequency or low-frequency components in the Doppler spectrum, it can be removed in the frequency domain using high-pass filters or band-stop filters (such as notched filters). This is particularly effective for detecting small moving targets behind the medium.

[0081] Clutter map adaptive processing: Before detection, a pre-scan is performed on the stationary medium cover to establish a "clutter map". During actual detection, the real-time echo data is compared with this clutter map, and known clutter components are subtracted to highlight the target signal.

[0082] Large-range target coarse measurement algorithms include:

[0083] Coarse measurements of long-range targets are handled by long-wave radar mode, leveraging its strong penetration and long-range detection capabilities. The core algorithm in this mode is standard FFT processing, which roughly estimates the target's range by identifying peaks in the beat signal spectrum. To address potential range and velocity ambiguity in long-range detection, a multi-frequency waveform approach can be employed. This involves transmitting chirp waveforms with different repetition periods, and then using the remainder theorem or the more efficient interleaved delay waveform method proposed in the patent to solve for the true unambiguous range and velocity.

[0084] Short-range, high-precision (1mm) ranging algorithm, including:

[0085] The user's requirement for "1mm high precision" cannot be met simply by increasing physical bandwidth, as achieving a distance resolution of 1mm theoretically requires a bandwidth of up to 150GHz, which is extremely impractical in real-world engineering. Therefore, the key to achieving high precision lies in employing advanced algorithms that exceed the limits of physical resolution, which constitutes the core technological advantage of this system.

[0086] The method for FFT refinement based on super-resolution employs a "two-stage algorithm".

[0087] The first stage (coarse localization) utilizes the wide bandwidth of the shortwave radar to perform conventional FFT processing, obtaining a relatively good base resolution (e.g., a resolution of 3.75 cm can be obtained using a 4 GHz bandwidth). This is sufficient to locate the target within a specific FFT frequency bin.

[0088] The second stage (refinement): Around the FFT peak (i.e., the bin containing the target), more complex super-resolution algorithms are applied for refinement to achieve the accuracy of the sub-FFT bins. For example, K-order polynomial interpolation is used to accurately estimate the peak location, or...

[0089] ChirpZ-transform (CZT) performs high-precision spectral analysis within a specific frequency range, thereby enabling more accurate estimation of frequencies within the FFT bin.

[0090] For high-precision ranging and micro-motion detection based on phase information, resolution alone is insufficient for detecting minute movements within short distances (3 cm). A more effective method is to utilize the phase information of the FMCW demodulated signal. Phase is extremely sensitive to changes in distance; even millimeter-level or sub-millimeter-level movements can cause considerable phase changes. For example, in a 6 GHz FMCW radar system, a 1 mm hand movement can result in a 14° phase change, which is easily detectable. This algorithm continuously monitors the phase change of the demodulated signal over time, accurately measures the phase drift, and can then inversely calculate the change in target distance, thus achieving micrometer-level or even sub-millimeter-level accuracy far exceeding the physical resolution limit.

[0091] Motion compensation and synchronization algorithms, including:

[0092] When a hybrid system is operating, even slight movements of the detection platform itself can introduce additional errors, affecting the accuracy of high-precision measurements. Therefore, state estimation algorithms such as Kalman filtering are needed to dynamically compensate for the measurement data. By fusing radar range and velocity measurements with the system's own motion information (e.g., from an inertial measurement unit, IMU), the measurement data can be corrected and compensated in real time, resulting in more accurate and stable range estimations.

[0093] Multi-level data fusion and decision optimization, including:

[0094] The fusion framework and strategy include: Improving the performance of a hybrid radar system is not simply about presenting data from two radars side-by-side; its true value comes from multi-level, intelligent data fusion. This invention employs a hierarchical fusion framework, including signal-level fusion, feature-level fusion, and decision-level fusion, to achieve comprehensive collaboration from raw signals to high-level decision-making. This hierarchical processing framework systematically utilizes the complementary information from long-wave and short-wave radars to maximize the overall system performance.

[0095]

[0096] The implementation logic for longwave and shortwave data fusion includes:

[0097] The fusion of long-wave and short-wave data aims to combine the advantages of both radars to form a complete detection view. At the signal layer, raw echo signals from different frequency bands are processed collaboratively to achieve a better signal-to-noise ratio than a single sensor.

[0098] The feature layer integrates key features extracted from long-wave and short-wave radar.

[0099] For example, long-wave radar provides information on the "presence" and approximate location of objects behind a medium, while short-wave radar provides precise distance information.

[0100] Decision-making integration is key to achieving intelligence. Based on the detection results of long-wave radar, the system designs decision logic to trigger short-wave radar to enter high-precision mode, and performs fine measurement on the area locked by long-wave radar, thereby achieving a balance between detection efficiency and accuracy.

[0101] Decision optimization and performance enhancement include designing a dynamic decision logic that dynamically adjusts the transmitted waveform, processing algorithm, and fusion strategy based on different operating modes and environmental conditions (such as near-field and far-field). For example, in short-range high-precision mode, the system will prioritize the use of phase information and super-resolution algorithms from short-wave radar; while in wide-range scanning mode, it will rely more on the FFT algorithm from long-wave radar. This multi-level fusion and decision optimization not only significantly improves detection accuracy but also reduces computational burden and enhances system real-time performance.

[0102] This invention proposes a comprehensive solution based on multi-band hybrid modulation wave radar, aiming to resolve the inherent contradiction between large range and high accuracy in non-metallic medium penetration detection. Through physical-level combination of long and short waves, waveform-level sawtooth / triangular hybridization, algorithm-level multi-stage processing (clutter suppression, coarse measurement, and high-precision fine measurement), and multi-level data fusion, a system blueprint capable of meeting the stringent requirements of "large range, short distance (3CM), and high accuracy (1mm)" has been successfully constructed.

[0103] Beneficial effects: (1) Utilizing the complementary advantages of long-wave penetration and short-wave high resolution; (2) Employing hybrid waveforms to solve multi-target and ambiguity problems; (3) Abandoning the traditional path of simply relying on physical bandwidth to achieve 1mm resolution, and instead adopting super-resolution algorithms and more insightful phase information detection technology; (4) Achieving intelligent collaboration between long-wave and short-wave data through hierarchical fusion. These technological innovations work together to enable the system to simultaneously complete large-scale penetrating detection and close-range micron-level high-precision measurement on a single platform.

[0104] The above specific embodiments further illustrate the purpose, technical solution, and beneficial effects of the present invention. It should be understood that the above are merely specific embodiments of the present invention and are not intended to limit the scope of protection of the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A method for penetrating and detecting non-metallic media using multi-band modulated wave radar, characterized in that, The detection method includes: Constructing a multi-band hybrid modulation wave radar architecture; Modulated waveforms that alternate or mix sawtooth and triangular wave modulation modes; A near-field strong clutter suppression algorithm is used to process the mixed modulated wave; A large-range coarse-measurement algorithm is used to estimate the target's distance; The distance to the target is calculated using a short-range, high-precision ranging algorithm; The Kalman filter state estimation algorithm is used to dynamically compensate the measurement data to obtain the distance estimation result; By utilizing the complementary information from long-wave and short-wave radars, a complete detection view can be formed.

2. The method for penetrating and detecting non-metallic media using multi-band modulated wave radar according to claim 1, characterized in that, The radar architecture utilizes a flexible software-defined radio (SDR) platform to alternately or hybridize the transmission of electromagnetic waves with different frequencies and modulation schemes, achieving complementary and synergistic performance. By combining the penetrating detection capability of long-wave radar with the high-resolution measurement capability of short-wave radar, the system leverages the advantages of each in different operating modes, achieving overall performance that surpasses that of single-band radars.

3. The method for penetrating and detecting non-metallic media using multi-band modulated wave radar according to claim 1, characterized in that, The modulated waveform that alternates or mixes sawtooth wave and triangular wave modulation modes specifically includes: By leveraging the advantages of both sawtooth and triangular waves, multi-target ranging and velocity measurement can be achieved within one system cycle, while significantly reducing the generation of false targets and lowering the computational load of intermediate frequency signal processing. Alternately use sawtooth waves for large-area coarse measurements, and use triangular waves for fine distance and speed measurements.

4. The method for penetrating and detecting non-metallic media using a multi-band modulated wave radar according to claim 1, characterized in that, The specific steps of processing the hybrid modulated wave using the near-field strong clutter suppression algorithm include: Time gating: After the echo signal arrives at the receiving end, a short delay window is set to directly ignore strong clutter from the front surface of the medium and only process the target echo signal that arrives later. Frequency domain filtering: Since stationary clutter appears as zero-frequency or low-frequency components in the Doppler spectrum, high-pass filters or band-stop filters are used to remove it in the frequency domain. Clutter map adaptive processing: Before detection, a pre-scan is performed on the stationary medium cover to establish a clutter map. During actual detection, the real-time echo data is compared with the clutter map to subtract known clutter components and highlight the target signal.

5. The method for penetrating and detecting non-metallic media using a multi-band modulated wave radar according to claim 1, characterized in that, The method of estimating the distance to a target using a large-range target coarse measurement algorithm specifically includes: Coarse measurements of large-range targets are performed using long-wave radar modes, taking advantage of their strong penetration and long-range detection capabilities. Using standard FFT processing, the distance to the target is roughly estimated by identifying peaks in the beat signal spectrum; A multi-frequency waveform is used to transmit Chirp waveforms with different repetition periods, and then the interleaved time-delay waveform method is used to solve for the true unambiguous distance and velocity.

6. The method for penetrating and detecting non-metallic media using a multi-band modulated wave radar according to claim 1, characterized in that, The calculation of the target distance using a short-range, high-precision ranging algorithm specifically includes: A two-stage algorithm is used for FFT refinement based on super-resolution. Phase 1: Utilize the wide bandwidth of the shortwave radar to perform conventional FFT processing to obtain the basic resolution; The second stage involves applying more complex super-resolution algorithms to refine the FFT peaks, thereby achieving the precision of the sub-FFT bins. High-precision ranging and micro-motion detection based on phase information: For micro-motion within a short distance of 3 cm, the phase information of the demodulated signal is used.

7. The method for penetrating and detecting non-metallic media using a multi-band modulated wave radar according to claim 1, characterized in that, The process of using the Kalman filter state estimation algorithm to dynamically compensate the measurement data and obtain the distance estimation result specifically includes: When the hybrid system is working, the Kalman filter state estimation algorithm is used to dynamically compensate the measurement data; By fusing radar distance and velocity measurements with the system's own motion information, the measurement data is corrected and compensated in real time, resulting in more accurate and stable distance estimation.

8. The method for penetrating and detecting non-metallic media using a multi-band modulated wave radar according to claim 1, characterized in that, The process of utilizing complementary information from long-wave and short-wave radars to form a complete detection view specifically includes: The fusion of long-wave and short-wave data aims to combine the advantages of both radars to form a complete detection view; In the signal layer, raw echo signals from different frequency bands are processed collaboratively to obtain a better signal-to-noise ratio feature layer than a single sensor, fusing key features extracted from long-wave and short-wave radars. Based on the detection results of the long-wave radar, decision logic is used to trigger the short-wave radar to enter high-precision mode, and to perform fine measurement on the area locked by the long-wave radar.

9. A method for penetrating and detecting non-metallic media using a multi-band modulated wave radar according to claim 8, characterized in that, The specific steps of triggering the shortwave radar to enter high-precision mode based on the detection results of the longwave radar include: A dynamic decision-making logic is constructed, in which the system dynamically adjusts the transmitted waveform, processing algorithm, and fusion strategy according to different working modes and environmental conditions; In the close-range high-precision mode, the phase information and super-resolution algorithm of the short-wave radar are used first; in the wide-range scanning mode, the FFT algorithm of the long-wave radar is used.

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