A long-time spectrum monitoring and nonlinear probing fusion detection system and method

Abstract

The present application belongs to the technical field of hidden spying device investigation, and particularly relates to a long-time spectrum monitoring and nonlinear detection fusion detection system and method, which comprises a detachably connected external independent antenna receiving unit and an integrated portable main control terminal unit, and the two establish a bidirectional communication link through a special wired cable. The present application integrates the spectrum monitoring system into the nonlinear detection visualization terminal, discards the double-terminal separation mode, and completes all operations, data display and layer matching in an integrated manner, thereby eliminating the artificial coordinate registration error from the root, and making the device operation more simple and the scene adaptability stronger. The present application filters the normalized civil electromagnetic signals through a public signal database, and only retains the instantaneous, intermittent and non-public abnormal signals characteristic of the spying device, thereby solving the problem of the traditional spectrum monitoring heat map disorder and the suspicious area mislabeling, and significantly improving the abnormal target recognition accuracy.

Description

Technical Field

[0001] This invention belongs to the field of concealed espionage device detection technology, specifically relating to a long-term spectrum monitoring and nonlinear detection fusion detection system and method. Background Technology

[0002] Currently, spectrum signal monitoring and nonlinear node harmonic detection are two mainstream technologies for regional spectrum control and investigation of concealed espionage devices in important locations. Existing methods use these two types of detection equipment completely independently, lacking a mature detection solution that integrates the hardware and software of the two, enables data exchange, and links the processes. Furthermore, individual detection equipment still has many core defects and cannot meet the requirements for high-precision, automated, and integrated investigation.

[0003] Independent broadband spectrum monitoring equipment can only detect eavesdropping devices that are emitting radio frequency signals. Most spy cameras and recording devices on the market use short-term intermittent transmission modes, making them prone to being missed by conventional short-term spectrum scans. Relying on manual long-term monitoring and recording of spectrum data is extremely costly, and the independent screen of the equipment can only output electromagnetic thermal maps, unable to simultaneously and accurately locate the target. At the same time, existing spectrum equipment lacks the ability to automatically filter public electromagnetic signals. Common public signals such as WIFI, mobile communications, and broadcasts can create a large number of false suspicious areas, interfering with investigation and judgment.

[0004] Independent handheld nonlinear node detectors lack the ability to predict the electromagnetic environment across the entire area. During inspections, staff need to perform point-by-point blind scans of the entire house and space. Inspections of large-area important locations are time-consuming and labor-intensive. The manual scanning process is prone to blind spots such as wall cavities and ceilings, posing a serious risk of missed detections. Furthermore, the equipment relies solely on harmonic signals for judgment and cannot distinguish whether the equipment has the ability to wirelessly transmit and leak information, resulting in a single dimension of risk assessment.

[0005] Currently, the industry's screening process involves purchasing and operating two separate sets of equipment: a standalone spectrum analyzer is used for short-term inspections, followed by a manual, handheld nonlinear scanning device for a full-area blind scan. The two sets of equipment are displayed on separate terminals with incompatible coordinate systems. Suspicious areas marked with spectrum markers require manual memorization and matching, resulting in significant matching errors, fragmented workflows, and a lack of automated, tiered screening and full-process data archiving capabilities. Consequently, the standardization and traceability of the screening process fail to meet the management standards for important government locations. In summary, the industry currently only has two separate, mature testing devices; there is no integrated testing solution, and a complete testing method lacking a unified terminal display, intelligent long-term spectrum filtering, automatic risk assessment, step-by-step verification via linked nonlinear modules, and automatic data retention. Summary of the Invention

[0006] To address the technical problems existing in the current industry investigation model, this invention provides a long-term spectrum monitoring and nonlinear detection fusion detection system and method.

[0007] To solve the above-mentioned technical problems, the technical solution adopted by the present invention is as follows: A long-term spectrum monitoring and nonlinear detection fusion detection system includes a detachably connected external independent antenna receiving unit and an integrated portable main control terminal unit, which establish a two-way communication link through a dedicated wired cable; The external independent antenna receiving unit is used for fixed-point, long-term, full-domain radio frequency signal acquisition. It includes a 360° rotating radio frequency base driving module, a 20MHz-6GHz broadband radio frequency receiving antenna module, a radio frequency signal conditioning and acquisition module, and a wired detachable signal transmission interface module. The 360° rotating radio frequency base driving module receives rotation control commands from the integrated portable main control terminal, driving the broadband radio frequency receiving antenna to rotate horizontally 360° back and forth. The 20MHz-6GHz broadband radio frequency receiving antenna module picks up analog spatial electromagnetic wave signals in the 20MHz-6GHz frequency band. The radio frequency signal conditioning and acquisition module performs radio frequency signal filtering, noise suppression, amplification, analog-to-digital conversion, and buffers long-time-series raw spectrum data. The wired detachable signal transmission interface module enables uplink transmission of spectrum data and downlink reception of control commands, and supports physical plug-and-play separation. The integrated portable main control terminal unit can be independently handheld and portable after disconnecting the external independent antenna receiving unit. It includes a signal intelligent processing core module, a nonlinear node detection hardware module, a dual-source fusion risk judgment module, a visualization display and human-computer interaction module, and a local encrypted storage and archiving module. The core module for intelligent signal processing has a built-in database of common electromagnetic signal features and a four-dimensional feature intelligent reasoning algorithm. It is used to filter normalized common electromagnetic interference signals, extract four-dimensional features of abnormal signals and divide suspicious areas, and output scanning control commands downward. The nonlinear node detection hardware module receives scanning control commands, outputs harmonic excitation beams in a directional manner, and collects target second and third harmonic amplitude and phase characteristic data. The dual-source fusion risk assessment module receives spectrum anomaly feature and harmonic detection feature data, and executes a two-dimensional closed-loop risk assessment logic. The visualization and human-computer interaction module uniformly calibrates the spectrum space coordinate system and the nonlinear beam scanning coordinate system, displays electromagnetic thermal layers, harmonic positioning marks, and graded highlighted suspicious areas on the same screen, and provides a human-computer operation interaction entry. The local encrypted storage and archiving module encrypts and stores the entire process of detection data and automatically generates standardized investigation reports.

[0008] The external independent antenna receiving unit supports 72 hours of uninterrupted full-domain radio frequency signal acquisition, completely retains the original data of radio frequency signal arrival angle, signal strength, and duration, and captures weak eavesdropping radio frequency signals that are transmitted intermittently and in short bursts.

[0009] The core module for intelligent signal processing can read locally cached raw spectrum data in offline mode and independently complete the entire calculation process of signal filtering, abnormal heat map generation, and suspicious area division.

[0010] The four-dimensional feature intelligent reasoning algorithm extracts the four-dimensional core features of the abnormal signal, namely the frequency of signal occurrence, duration, signal strength, and spatial distribution. Through quantitative analysis, it automatically distinguishes between suspicious areas and safe areas and generates a hierarchical investigation sequence, which is then pushed to the visualization display and human-computer interaction module.

[0011] The closed-loop judgment logic of the dual-source fusion risk judgment module includes: If abnormal spectral signals and effective harmonic responses are present synchronously, it is identified as a high-risk target for active intermittent espionage. If only abnormal spectrum signals are present and there is no harmonic response, it is determined to be a common wireless interference source, thus eliminating the risk of eavesdropping. Regions without spectral anomalies are directly identified as environmentally safe, eliminating the need for nonlinear harmonic scanning.

[0012] The locally encrypted storage and archiving module retains data including long-term monitoring raw spectrum data, public signal filtering logs, risk-level area coordinates, harmonic location data, dual-source determination conclusions, and full-process investigation time trajectories.

[0013] A fusion detection method combining long-range time-frequency spectral monitoring and nonlinear detection includes the following steps: S1. The system can be detached and deployed with integrated calibration; the external independent antenna receiving unit is deployed to the monitoring point in the place to be inspected and connected to the integrated portable main control terminal unit through wired cable; the main control terminal automatically completes the unified calibration of the spatial coordinates of the spectrum acquisition module and the nonlinear node detection module, so that the reference of the two types of detection layers is matched; S2, 72-hour full-range long-term spectrum acquisition; activate uninterrupted monitoring mode, 360° rotating broadband antenna to acquire RF signals across the 20MHz-6GHz full-band frequency range at all times, and cache raw RF data for all time periods; S3, intelligent spectrum layering and filtering and device switching; after the acquisition cycle ends, the external antenna receiving unit is physically disconnected and the main control terminal switches to offline portable mode; the signal intelligent processing core module retrieves local spectrum raw data and automatically filters WIFI, Bluetooth, base stations, and civilian remote control normal public signals based on the public signal feature database to generate a heat map of pure abnormal electromagnetic signals. S4. Intelligent reasoning to classify suspicious areas; extract four-dimensional features of abnormal signals, including frequency of occurrence, duration, signal strength, and spatial distribution. Quantitatively analyze and judge these features using a four-dimensional feature intelligent reasoning algorithm to classify suspicious areas and safe areas. Highlight suspicious areas on a heatmap and synchronize their spatial coordinates. S5. Directional harmonic scanning of suspicious areas: The operator holds the main control terminal and points it at the suspicious area according to the visual interface prompts. The nonlinear node detection hardware module performs fine beam scanning to collect regional harmonic amplitude and phase characteristic data. S6. Spectrum-Harmonic Dual-Source Closed-Loop Intelligent Verification and Judgment: For suspicious areas marked by the spectrum, a two-way judgment is performed based on the spectrum characteristics and harmonic response, and the final risk level is output. S7. Automatic encryption and archiving of data throughout the entire process; the system automatically records all detection dimension data, encrypts and stores it locally, and generates standardized investigation reports to achieve traceability and verification of the entire detection process.

[0014] In step S2, the monitoring duration can be customized, and in step S3, the spectrum receiving frequency band range of the broadband radio frequency receiving antenna can be customized and adjusted according to the site management requirements.

[0015] The external independent antenna receiving unit in step S1 can be replaced by a distributed multi-terminal network acquisition structure for collaborative spectrum acquisition at multiple points in a large space.

[0016] The four-dimensional feature intelligent reasoning algorithm can iteratively expand the feature sample library of espionage devices, enabling automatic identification and classification of suspicious espionage device types.

[0017] Compared with the prior art, the beneficial effects of this invention are: 1. Achieve integrated control on a single terminal, significantly improving positioning and matching accuracy. This invention integrates the spectrum monitoring system into a nonlinear detection visualization terminal, abandoning the dual-terminal separation mode. All operations, data display, and layer matching are completed in one integrated manner, eliminating manual coordinate registration errors at the source. The equipment is easier to operate and has stronger scene adaptability.

[0018] 2. Intelligent spectrum filtering significantly reduces false positives and interference. This invention filters routine civilian electromagnetic signals through a public signal database, retaining only instantaneous, intermittent, and non-public abnormal signals characteristic of espionage devices. This solves the problems of cluttered traditional spectrum monitoring heatmaps and mislabeling of suspicious areas, significantly improving the accuracy of abnormal target identification.

[0019] 3. The risk assessment and screening process is highly integrated, achieving fully automated and standardized detection. This invention uses intelligent reasoning algorithms to unify risk classification and automatically generate screening sequences. Relying on an integrated system, it autonomously completes layer-by-layer scanning, ensuring a closed-loop, continuous process without human intervention. This completely avoids the problems of subjective human judgment bias and missed scans, significantly reducing labor costs.

[0020] 4. The dual-source closed-loop verification logic is rigorous, and judgment loopholes are completely fixed. This invention optimizes the bidirectional judgment mechanism of spectrum and harmonics, specifically identifying pure spectrum interference signals, solving the problems of self-contradictory logic and inability to distinguish interfering devices in traditional logic, and making the detection and judgment results more accurate and rigorous.

[0021] 5. Automatic data archiving throughout the entire process, meeting the traceability needs of important scenarios. This invention automatically records and encrypts all data throughout the entire process, forming a complete investigation ledger, enabling full traceability of the testing process and results, and fully adapting to the high-standard security control requirements of important government agencies and locations. Attached Figure Description

[0022] To more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings in the following description are merely exemplary, and those skilled in the art can derive other embodiments based on the provided drawings without creative effort.

[0023] The structures, proportions, sizes, etc. illustrated in this specification are only for the purpose of assisting those skilled in the art in understanding and reading the content disclosed herein, and are not intended to limit the conditions under which the present invention can be implemented. Therefore, they have no substantial technical significance. Any modifications to the structure, changes in the proportions, or adjustments to the size, without affecting the effects and objectives that the present invention can produce, should still fall within the scope of the technical content disclosed in the present invention.

[0024] Figure 1 This is a block diagram illustrating the hardware composition principle of the present invention; Figure 2 This is a schematic diagram of the detection process of the present invention. Detailed Implementation

[0025] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. These descriptions are only for further illustrating the features and advantages of the present invention, and not for limiting the claims of the present invention. Based on the embodiments in this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0026] The specific embodiments of the present invention will be described in further detail below with reference to the accompanying drawings and examples. The following examples are for illustrative purposes only and are not intended to limit the scope of the invention.

[0027] This invention is applicable to important locations such as confidential conference rooms, secret offices, archives, and secure computer rooms in government agencies. It enables fully automated screening of concealed electronic espionage devices, including those that emit intermittent signals, trigger instantaneously, or remain silent while recording, recording, wireless eavesdropping, and GPS tracking. It can complete 72 hours of long-term, full-domain spectrum monitoring without continuous human supervision. Combined with nonlinear node harmonic detection, it achieves dual-dimensional closed-loop verification, meeting the standardized and traceable security screening requirements of confidential locations.

[0028] Example 1

[0029] This system adopts a modular, detachable hardware architecture, such as Figure 1 As shown, it includes an external independent antenna receiving unit and an integrated portable main control terminal unit. The two are detachably connected by a dedicated wired cable, which enables bidirectional transmission of control commands and spectrum data.

[0030] The external independent antenna receiving unit serves as a fixed-point acquisition device, and internally includes a 360° rotating RF base drive module, a 20MHz-6GHz broadband RF receiving antenna module, an RF signal conditioning and acquisition module, and a wired detachable signal transmission interface module.

[0031] The 360° rotating RF base drive module receives control commands from the main control terminal and drives the broadband RF antenna to rotate horizontally 360° back and forth, supporting 72 hours of continuous and stable operation to ensure the acquisition of RF signals without blind spots throughout the entire area.

[0032] The 20MHz-6GHz broadband radio frequency receiving antenna module covers the 20MHz-6GHz frequency band and picks up radio frequency analog signals generated by permanent public signals, short bursts, and intermittent eavesdropping devices in the venue.

[0033] The radio frequency signal conditioning and acquisition module performs filtering, noise suppression, amplification, and analog-to-digital conversion on the analog radio frequency signal, caches 72 hours of long-sequence spectrum raw data, and completely retains the signal arrival angle, intensity, and duration information.

[0034] The wired detachable signal transmission interface module enables uplink of spectrum data and downlink of control commands. The physical interface supports plug-and-play separation and can be separated from the main control terminal after spectrum acquisition is completed.

[0035] The integrated portable main control terminal unit can be operated independently by hand after disconnecting the external antenna. It integrates a core module for intelligent signal processing, a hardware module for nonlinear node detection, a dual-source fusion risk assessment module, a visualization and human-computer interaction module, and a local encrypted storage and archiving module. It is factory-calibrated with two sets of spatial coordinate systems: spectrum and nonlinear detection.

[0036] The core module for intelligent signal processing has a built-in database of public electromagnetic signal features and a four-dimensional feature intelligent reasoning algorithm. In offline mode, it can read locally cached spectrum data, automatically filter common public signals such as WIFI, Bluetooth, and base stations, extract four-dimensional features of abnormal signal frequency, duration, intensity, and spatial distribution, divide suspicious areas, and generate investigation sequences.

[0037] The nonlinear node detection hardware module receives the investigation command, emits harmonic excitation beams to suspicious areas, collects the second and third harmonic amplitude and phase characteristics of the target, and identifies electronic devices containing semiconductor nodes.

[0038] The dual-source fusion risk assessment module simultaneously reads spectrum anomaly data and harmonic detection data to perform assessments: if both abnormal spectrum and effective harmonic response are present, it is determined to be a high-risk active eavesdropping device; if only spectrum anomaly exists without harmonics, it is determined to be wireless interference; areas without spectrum anomalies are directly determined to be safe.

[0039] The visualization and human-computer interaction module displays electromagnetic and thermal layers, harmonic positioning marks, and highlighted suspicious areas on the same screen, and provides interactive functions such as device configuration, monitoring start / stop, and report export.

[0040] The local encrypted storage and archiving module encrypts and retains the entire process of detection data, automatically generates standardized investigation reports, and achieves full traceability.

[0041] Example 2

[0042] Using a medium-sized, classified conference room of a government agency as the implementation scenario, such as Figure 2 As shown, the complete closed-loop detection process of this invention is executed.

[0043] The first step is to complete the detachable deployment and integrated calibration of the system. The external antenna receiving unit is placed at the monitoring point in the conference room and connected to the integrated main control terminal through a cable. The device automatically unifies the spatial coordinates of the two modules and completes the layer matching.

[0044] The second step involves initiating a 72-hour full-range long-term spectrum acquisition, with a 360° rotating antenna continuously acquiring radio frequency signals across the entire 20MHz-6GHz band, fully storing the original signal data for each time period, and capturing intermittent and momentary weak transmission signals from eavesdropping devices.

[0045] After the third step of spectrum acquisition is completed, the external antenna is disconnected, and the main control terminal switches to offline portable mode. The intelligent signal processing module retrieves all spectrum data, filters civilian permanent electromagnetic signals based on the public signal database, and generates a clean abnormal electromagnetic thermal distribution map.

[0046] The fourth step, the intelligent signal processing module, extracts the four-dimensional core features of the abnormal signal and uses the built-in reasoning algorithm to quantify and judge the situation. The area behind the decorative painting on the north wall and the table ornaments on the south side are classified as suspicious areas and highlighted on the heat map.

[0047] In the fifth step, the operator holds the main control terminal and points it at the suspicious area according to the on-screen prompts. The nonlinear detection module automatically performs a fine beam scan and collects harmonic characteristic data of the corresponding area.

[0048] The sixth step involves the system performing a dual-source closed-loop verification of spectrum and harmonics. The decorative painting area on the north wall exhibits both abnormal spectrum and harmonic response, indicating it is a high-risk active eavesdropping device. The table ornaments only show spectrum interference and have no harmonic output, indicating they are a source of interference from the wireless intercom in the adjacent room, thus eliminating the risk of eavesdropping. The remaining areas without spectrum markings are deemed safe.

[0049] In the seventh step, the system automatically encrypts and stores all information, including raw spectrum data, filtering logs, risk classification, harmonic coordinates, and judgment conclusions, and generates a standardized classified site investigation report for retention. The entire process of detection records can be verified and traced.

[0050] Example 3

[0051] This invention provides multiple alternative implementation schemes that do not change the core architecture.

[0052] The first alternative is distributed multi-terminal network spectrum acquisition, which replaces the single-point external antenna with multiple antennas deployed in a distributed manner. The spectrum data is collected synchronously from multiple points and aggregated to the same master control terminal for processing. This is suitable for ultra-large space scenarios and improves the accuracy of signal recognition and risk classification.

[0053] The second alternative eliminates the external separate antenna unit and integrates the small radio frequency antenna and rotation drive circuit into the main control terminal body. It does not require external cable separation and is only suitable for simple inspection in a small area in a single office. It cannot complete 72-hour long-term fixed-point monitoring.

[0054] The third alternative keeps the hardware and basic detection process unchanged, iteratively upgrades the four-dimensional feature intelligent reasoning algorithm, expands the feature sample library of espionage devices, and adds an automatic classification and identification function for suspicious espionage devices.

[0055] The fourth alternative supports customizable monitoring duration, adjusting the continuous monitoring cycle according to the site's control level; it also allows for customizable antenna spectrum reception range to adapt to different site radio control requirements.

[0056] Example 4

[0057] Compared with the traditional separate display and operation scheme of independent equipment, the present invention has many beneficial effects, which can be intuitively verified in the above-mentioned conference room implementation scenario.

[0058] This invention employs a single-terminal integrated control system, with two sets of detection layers naturally matched, completely eliminating errors caused by manual coordinate matching and significantly improving positioning accuracy.

[0059] By relying on a public signal database to automatically filter civilian electromagnetic interference, heat map clutter is significantly reduced, the probability of signal misjudgment is lowered, and the accuracy of abnormal target identification is improved.

[0060] The system relies on intelligent reasoning to automatically divide risk areas and generate investigation sequences. The entire detection process is executed automatically and in a coherent manner, reducing subjective bias in human operation, lowering manpower input, and avoiding missed scans and inspections.

[0061] The dual-source closed-loop verification mechanism of spectrum and harmonics can distinguish between real espionage devices and purely wireless interference, making up for the loopholes in the traditional single-dimensional judgment logic, and the detection results are more rigorous and accurate.

[0062] The system automatically encrypts and archives the entire process of testing data, generates standardized investigation logs, and fully meets the confidentiality and control requirements of the testing process and results traceability in important government locations.

[0063] The above description only illustrates the preferred embodiments of the present invention. However, the present invention is not limited to the above embodiments. Within the scope of knowledge possessed by those skilled in the art, various changes can be made without departing from the spirit of the present invention, and all such changes should be included within the protection scope of the present invention.

Claims

1. A long-term spectrum monitoring and nonlinear detection fusion detection system, characterized in that: It includes a detachable external independent antenna receiving unit and an integrated portable main control terminal unit, which establish a two-way communication link through a dedicated wired cable; The external independent antenna receiving unit is used for fixed-point, long-term, full-domain radio frequency signal acquisition. It includes a 360° rotating radio frequency base driving module, a 20MHz-6GHz broadband radio frequency receiving antenna module, a radio frequency signal conditioning and acquisition module, and a wired detachable signal transmission interface module. The 360° rotating radio frequency base driving module receives rotation control commands from the integrated portable main control terminal, driving the broadband radio frequency receiving antenna to rotate horizontally 360° back and forth. The 20MHz-6GHz broadband radio frequency receiving antenna module picks up analog spatial electromagnetic wave signals in the 20MHz-6GHz frequency band. The radio frequency signal conditioning and acquisition module performs radio frequency signal filtering, noise suppression, amplification, analog-to-digital conversion, and buffers long-time-series raw spectrum data. The wired detachable signal transmission interface module enables uplink transmission of spectrum data and downlink reception of control commands, and supports physical plug-and-play separation. The integrated portable main control terminal unit can be independently handheld and portable after disconnecting the external independent antenna receiving unit. It includes a signal intelligent processing core module, a nonlinear node detection hardware module, a dual-source fusion risk judgment module, a visualization display and human-computer interaction module, and a local encrypted storage and archiving module. The core module for intelligent signal processing has a built-in database of common electromagnetic signal features and a four-dimensional feature intelligent reasoning algorithm. It is used to filter normalized common electromagnetic interference signals, extract four-dimensional features of abnormal signals and divide suspicious areas, and output scanning control commands downward. The nonlinear node detection hardware module receives scanning control commands, outputs harmonic excitation beams in a directional manner, and collects target second and third harmonic amplitude and phase characteristic data. The dual-source fusion risk assessment module receives spectrum anomaly feature and harmonic detection feature data, and executes a two-dimensional closed-loop risk assessment logic. The visualization and human-computer interaction module uniformly calibrates the spectrum space coordinate system and the nonlinear beam scanning coordinate system, displays electromagnetic thermal layers, harmonic positioning marks, and graded highlighted suspicious areas on the same screen, and provides a human-computer operation interaction entry. The local encrypted storage and archiving module encrypts and stores the entire process of detection data and automatically generates standardized investigation reports.

2. The long-term spectrum monitoring and nonlinear detection fusion detection system according to claim 1, characterized in that: The external independent antenna receiving unit supports 72 hours of uninterrupted full-domain radio frequency signal acquisition, completely retains the original data of radio frequency signal arrival angle, signal strength, and duration, and captures weak eavesdropping radio frequency signals that are transmitted intermittently and in short bursts.

3. The long-term spectrum monitoring and nonlinear detection fusion detection system according to claim 1, characterized in that: The core module for intelligent signal processing can read locally cached raw spectrum data in offline mode and independently complete the entire calculation process of signal filtering, abnormal heat map generation, and suspicious area division.

4. The long-term spectrum monitoring and nonlinear detection fusion detection system according to claim 1, characterized in that: The four-dimensional feature intelligent reasoning algorithm extracts the four-dimensional core features of the abnormal signal, namely the frequency of signal occurrence, duration, signal strength, and spatial distribution. Through quantitative analysis, it automatically distinguishes between suspicious areas and safe areas and generates a hierarchical investigation sequence, which is then pushed to the visualization display and human-computer interaction module.

5. The long-term spectrum monitoring and nonlinear detection fusion detection system according to claim 1, characterized in that: The closed-loop judgment logic of the dual-source fusion risk judgment module includes: If abnormal spectral signals and effective harmonic responses are present synchronously, it is identified as a high-risk target for active intermittent espionage. If only abnormal spectrum signals are present and there is no harmonic response, it is determined to be a common wireless interference source, thus eliminating the risk of eavesdropping. Regions without spectral anomalies are directly identified as environmentally safe, eliminating the need for nonlinear harmonic scanning.

6. The long-term spectrum monitoring and nonlinear detection fusion detection system according to claim 1, characterized in that: The locally encrypted storage and archiving module retains data including long-term monitoring raw spectrum data, public signal filtering logs, risk-level area coordinates, harmonic location data, dual-source determination conclusions, and full-process investigation time trajectories.

7. A long-term spectrum monitoring and nonlinear detection fusion detection method based on the system described in any one of claims 1-6, characterized in that, Includes the following steps: S1. The system can be detached and deployed with integrated calibration; the external independent antenna receiving unit is deployed to the monitoring point in the place to be tested and connected to the integrated portable main control terminal unit through wired cable; The main control terminal automatically completes the unified calibration of the spatial coordinates of the spectrum acquisition module and the nonlinear node detection module, so that the reference of the two types of detection layers is matched. S2, 72-hour full-area long-term spectrum acquisition; Activate the continuous monitoring mode, and the 360° rotating broadband antenna collects radio frequency signals across the entire frequency band from 20MHz to 6GHz at all times, and caches the raw radio frequency data for all time periods. S3, intelligent spectrum layering and filtering and device switching; after the acquisition cycle ends, the external antenna receiving unit is physically disconnected and the main control terminal switches to offline portable mode; the signal intelligent processing core module retrieves local spectrum raw data and automatically filters WIFI, Bluetooth, base stations, and civilian remote control normal public signals based on the public signal feature database to generate a heat map of pure abnormal electromagnetic signals. S4. Intelligent reasoning to classify suspicious areas; extract four-dimensional features of abnormal signals, including frequency of occurrence, duration, signal strength, and spatial distribution. Quantitatively analyze and judge these features using a four-dimensional feature intelligent reasoning algorithm to classify suspicious areas and safe areas. Highlight suspicious areas on a heatmap and synchronize their spatial coordinates. S5. Directional harmonic scanning of suspicious areas: The operator holds the main control terminal and points it at the suspicious area according to the visual interface prompts. The nonlinear node detection hardware module performs fine beam scanning to collect regional harmonic amplitude and phase characteristic data. S6. Spectrum-Harmonic Dual-Source Closed-Loop Intelligent Verification and Judgment: For suspicious areas marked by the spectrum, a two-way judgment is performed based on the spectrum characteristics and harmonic response, and the final risk level is output. S7. Automatic encryption and archiving of data throughout the entire process; the system automatically records all detection dimension data, encrypts and stores it locally, and generates standardized investigation reports to achieve traceability and verification of the entire detection process.

8. The long-term spectrum monitoring and nonlinear detection fusion detection method according to claim 7, characterized in that, In step S2, the monitoring duration can be customized, and in step S3, the spectrum receiving frequency band range of the broadband radio frequency receiving antenna can be customized and adjusted according to the site management requirements.

9. The long-term spectrum monitoring and nonlinear detection fusion detection method according to claim 7, characterized in that, The external independent antenna receiving unit in step S1 can be replaced by a distributed multi-terminal network acquisition structure for collaborative spectrum acquisition at multiple points in a large space.

10. The long-term spectrum monitoring and nonlinear detection fusion detection method according to claim 7, characterized in that, The four-dimensional feature intelligent reasoning algorithm can iteratively expand the feature sample library of espionage devices, enabling automatic identification and classification of suspicious espionage device types.

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