A terahertz ground detection system and detection method for detecting vehicle bottom safety

Abstract

The present invention provides a terahertz ground detection system for detecting the safety of the bottom of a vehicle, comprising a terahertz exciter, a terahertz detector, a near-infrared detection system and a data processing system, wherein the terahertz exciter and the terahertz detector are both arranged underground; the terahertz exciter generates terahertz waves by excitation, which are emitted to a target vehicle, and the terahertz signal reflected by the bottom of the target vehicle is transmitted to the terahertz detector, and the terahertz detector generates terahertz spectrum information according to the terahertz signal reflected by the bottom of the target vehicle, and transmits the information to the data processing system for processing, generates a corresponding relationship between the terahertz spectrum information and an unidentified object at the bottom of the target vehicle, and displays the result on a computer; after the near-infrared detection system detects the target vehicle information, the information is sent to the data processing system. The present invention also provides a detection method for a terahertz ground detection system. The present invention can detect bombs hidden at the bottom of a vehicle, and the detection result is accurate.

Description

Technical Field

[0001] The present invention belongs to the field of safety detection, and in particular provides detection of the bottom of a vehicle on a road, and specifically relates to a terahertz ground detection system and a detection method for detecting the safety of the bottom of a vehicle. Background Art

[0002] At present, the inspection of vehicles and other means of transportation is still limited to detecting metal. It is difficult to detect rubber and plastic bombs hidden under the bottom of the vehicle, which poses a threat to safety.

[0003] The detection of hidden rubber plastic bombs is an extremely difficult problem. High sensitivity and special analytical methods are required to detect hidden rubber plastic bombs. The detection equipment is required to have high sensitivity and specificity, in order to eliminate the interference of non-explosives on explosives. One of the effective methods used to search for hidden rubber plastic bombs is dogs. This special dog can identify rubber plastic bombs after special training, but there are difficulties such as high training costs and difficulty in controlling, so people can only use other methods. At present, there are many detection methods. Bomb detection technology mainly includes electron capture detection technology, X-ray method, ion mobility spectrometry detection technology, handheld metal detectors, etc. However, these methods have certain limitations in practical applications. Electron capture detectors can be used to detect explosive vapors. They are inexpensive, have a fast response speed and high sensitivity, but the detection results are not specific, the mechanism is complex and the operation is difficult. The X-ray method is not accurate because it cannot distinguish between explosives and non-explosives of similar density. Ion mobility spectrometry detection technology can only separate pairs of ions, making it difficult to accurately measure ions, and its selectivity is not very good. Handheld metal detectors are designed to detect metal objects carried by people or objects. They can detect weapons, explosives or small metal objects in packages, luggage, letters, fabrics, etc. carried by people. The special appearance of their sensitive surfaces makes operation simple and easy, but handheld metal detectors are only sensitive to metal bombs and are difficult to detect rubber and plastic bombs. There are also differences in detection distances. Too far a distance may result in failure to detect metal bombs.

[0004] In traditional vehicle inspection technology, when vehicles pass through important roads, it is impossible to stop all vehicles for inspection due to the large number of vehicles and high speed, especially the bottom of the vehicle is often overlooked. In addition, the vehicle is usually parked and then a long pole detection device is inserted under the vehicle to record video or take photos. Therefore, traditional technology still has the possibility of missed inspections, and the operation is cumbersome, time-consuming and labor-intensive.

[0005] Terahertz waves (Terahertz or terahertz radiation, T-rays, submillimeter waves, far infrared, referred to as "THz") usually refer to electromagnetic radiation with a frequency range of 0.1 to 10THz (1THz=1012Hz). It is a general term for a specific band. It is very rare to name a frequency band by frequency. However, "terahertz" has become a symbolic symbol in this field. The frequency of 0.1 to 10THz is different from other frequency bands. Terahertz spectroscopy technology is widely used in various fields because the photon energy of terahertz radiation is low. It is a non-contact measurement technology that does not generate radiation to the object to be detected. In addition, terahertz waves have good penetration characteristics for packaging. Compared with X-rays, it will not destroy the material to be detected due to photoionization. It has a high signal-to-noise ratio and can quickly analyze and identify subtle changes in the object to be detected.

[0006] Terahertz spectroscopy technology, with its characteristics of high resolution, high sensitivity and high selectivity, provides a new detection idea for the detection of explosives under the vehicle. At present, there is no relevant technology that uses terahertz spectroscopy technology to detect dangerous goods under the vehicle. Summary of the invention

[0007] The purpose of the present invention is to solve the problems in the background technology and provide a terahertz ground detection system and a detection method for detecting the safety of the bottom of a vehicle. The present invention provides a terahertz ground detection system and a detection method for detecting the safety of the bottom of a vehicle, which solves the problem of difficulty in detecting bombs hidden under the vehicle.

[0008] The above technical purpose of the present invention is achieved through the following technical solutions:

[0009] A terahertz ground detection system for detecting the safety of the bottom of a vehicle, comprising a terahertz exciter, a terahertz detector, a near-infrared detection system and a data processing system, wherein the terahertz exciter and the terahertz detector are both arranged underground, and the terahertz detector is connected to the data processing system;

[0010] The terahertz exciter generates a terahertz wave signal, which is emitted to the target vehicle, and transmits the terahertz signal reflected by the bottom of the target vehicle to the terahertz detector, which generates terahertz spectrum information according to the terahertz signal reflected by the bottom of the target vehicle and transmits the information to the data processing system for processing, and the data processing system processes the terahertz spectrum information, generates a corresponding relationship between the terahertz spectrum information and the unknown object at the bottom of the target vehicle, forms an image and displays the result on a computer;

[0011] After the near infrared detection system detects the information of the target vehicle, the information is sent to the data processing system.

[0012] By using the terahertz ground detection system in the solution of the present invention, the terahertz system can be used to preliminarily detect whether there are any unidentified objects or other dangerous goods under the vehicle. If there are unidentified objects or other dangerous goods, the suspicious target vehicle can be stopped for further careful inspection to achieve the purpose of detection. The system does not affect the passage of vehicles, there will be no missed inspections, and it saves time and effort.

[0013] As described above, a terahertz ground detection system for detecting the safety of the bottom of a vehicle, the near-infrared detection system includes a near-infrared emitter and a near-infrared detector, the near-infrared emitter emits infrared rays to the target vehicle, the infrared rays are reflected to the near-infrared detector, the near-infrared detector transmits information to the data processing system, and displays the results on the computer. Under this technical condition, the near-infrared detector is for night vision and assists terahertz in image detection, because although terahertz has penetrability, the image resolution is low, and although infrared has no penetrability, the resolution is high. Especially in dark light, such as at night, if the bottom of the vehicle directly absorbs obvious suspicious objects without camouflage, it can be directly seen through the near-infrared detector.

[0014] A terahertz ground detection system for detecting the safety of the bottom of a vehicle as described above also includes a visible camera device, which works with a CCD chip, transmits the information collected by the visible camera device to a data processing system, and displays the imaging results of the visible camera device on a computer. In the present invention, CCD is the abbreviation of Charge Coupled Device, which can convert light into electric charge and store and transfer the electric charge, and can also take out the stored electric charge to change the voltage. The CCD visible camera device has the advantages of small size, light weight, no influence of magnetic field, and anti-vibration and anti-impact. CCD can be used in a miniature camera, and the CCD photosensitive element can directly convert the optical signal into an analog current signal, and the current signal is amplified and converted to analog to digital to realize the acquisition, storage, transmission, processing and reproduction of the image. Its advantages are small size and light weight; low power consumption, low operating voltage, anti-impact and vibration, stable performance, long life; fast response speed, small image distortion, and no residual image.

[0015] In the above-mentioned terahertz ground detection system for detecting the safety of the bottom of a vehicle, glass is arranged on the ground, the terahertz exciter emits terahertz waves at a certain angle, the terahertz waves pass through one side of the glass to reach the target vehicle, and the terahertz waves reflected and refracted by the target vehicle pass through the other side of the glass to reach the terahertz detector. Under this technical condition, the function of one side of the glass is to allow the terahertz waves to pass through to the bottom of the vehicle, and the function of the other side of the glass is to allow the terahertz waves reflected by the bottom of the vehicle to pass through to the terahertz detector.

[0016] In the above-mentioned terahertz ground detection system for detecting the safety of the bottom of a vehicle, the terahertz exciter includes a terahertz exciter body, a cylindrical mirror, a first convex lens and a first concave lens, and the terahertz wave emitted by the terahertz exciter body passes through the cylindrical mirror, the first convex lens and the first concave lens in sequence to reach the bottom of the target vehicle. Under this technical condition, the terahertz wave emitted from the terahertz exciter first passes through the cylindrical mirror to convert the point light source into a line light source, and the line light source passes through the first convex lens and the first concave lens to become a parallel light source to the bottom of the car.

[0017] In the above-mentioned terahertz ground detection system for detecting the safety of the bottom of a vehicle, the terahertz detector includes a polyethylene lens, a second concave lens, a second convex lens and a terahertz detector body, and the terahertz wave reflected by the bottom of the target vehicle passes through the polyethylene lens, the second concave lens and the second convex lens in sequence to reach the terahertz detector body. Under this technical condition, the terahertz wave reflected from the bottom of the car passes through the polyethylene lens, the second concave mirror and the second convex mirror, and finally becomes a line light source to reach the terahertz detector.

[0018] In the above-mentioned terahertz ground detection system for detecting the safety of the bottom of a vehicle, the data processing system is also used to receive the terahertz spectrum information of the unknown vehicle, compare it with the corresponding relationship between the terahertz spectrum information and the unknown object under the vehicle, form an image and display the result on the computer. In other words, the terahertz ground detection system can detect both suspicious target vehicles and other unknown vehicles passing by the lane, and can achieve continuous detection.

[0019] The terahertz ground detection system for detecting the safety of the bottom of a vehicle as described above also includes a Raman detection system for analyzing the composition of dangerous goods at the bottom of the target vehicle to determine whether they are explosives, and the Raman detection system includes a Raman spectrometer. If an unknown object is detected by terahertz, the target vehicle is stopped at this time, and the unknown object is detected by the Raman spectrometer. By comparing it with the terahertz reflection Raman spectrum database, the dangerous goods at the bottom of the target vehicle are analyzed for composition, so as to determine whether they are explosives.

[0020] Based on the same inventive concept, the present invention also provides a detection method using the terahertz ground detection system as described above, comprising the following steps:

[0021] S1. The terahertz wave emitted by the terahertz exciter is collimated and expanded, and the point light source of the terahertz laser is changed into a stable line light source, which is then irradiated to the bottom of the target vehicle;

[0022] S2. The terahertz detector detects the terahertz wave reflected from the bottom of the target vehicle and transmits it to the data processing system through the collection optical system;

[0023] S3. The data processing system analyzes the detection information of the bottom of the target vehicle according to the detection data of the terahertz detector and forms an image to be displayed on the computer;

[0024] S4. If the image in step S3 is an unidentified object, stop the target vehicle, detect the unidentified object with a Raman spectrometer, and analyze the composition of the dangerous goods at the bottom of the target vehicle by comparing it with the terahertz reflection Raman spectrum database to determine whether it is an explosive.

[0025] As described above, the detection method of the terahertz ground detection system, the steps S1 to S3 also include detection using a near-infrared detection system, the near-infrared detection system includes a near-infrared emitter and a near-infrared detector, and the specific steps are: in the step S1, the near-infrared emitter emits infrared rays to the target vehicle; in the step S2, the infrared rays are reflected to reach the near-infrared detector, and the near-infrared detector transmits information to the data processing system; in the step S3, the data processing system analyzes the detection information of the bottom of the target vehicle according to the detection data of the near-infrared detector, and displays the results on the computer.

[0026] In the detection method of the terahertz ground detection system as described above, the near-infrared detection system is used in a dark environment, such as at night or during the day when the light is dark, and the near-infrared detection system is not affected by light.

[0027] Compared with the prior art, the present invention has the following advantages and beneficial effects:

[0028] 1. The present invention provides a terahertz ground detection system for detecting the safety of the bottom of a vehicle, comprising a terahertz exciter, a terahertz detector, a near-infrared detection system and a data processing system; the terahertz exciter located below the ground emits terahertz waves at a certain angle, and the terahertz waves reach the vehicle, and the reflected and refracted terahertz waves reach the terahertz detector, thereby forming an image on a computer. Since different objects have different degrees of absorption of terahertz waves, the shape of dangerous goods such as plastic bombs can be detected.

[0029] 2. The terahertz ground detection system for detecting the safety of the bottom of a vehicle provided by the present invention has an optical system design, where the point light source is changed into a line light source for scanning, and then the acquisition part collects images and data, making the imaging range wider. The solution itself does not emit any radiation, the device has low power consumption, good concealment and low price.

[0030] 3. The terahertz ground detection system for detecting the safety of the bottom of a vehicle provided by the present invention has the unique advantages of strong penetration, precise identification of specific fingerprint spectrum, long-distance detection and harmlessness to the human body in detecting explosives, compared with other traditional detection methods such as electron capture detection technology, X-ray method, ion mobility spectrum detection technology, handheld metal detectors, etc. According to the above advantages, the terahertz wave technology can not only detect the shape of the explosive, but also identify the explosive through spectral information.

[0031] 4. The present invention provides a terahertz ground detection system for detecting the safety of the bottom of a vehicle. By combining terahertz technology with a near-infrared detection system and a CCD system, terahertz imaging technology has the advantages of both structural imaging and functional imaging. Therefore, it can not only perform high-resolution identification of traditional knives, guns and other metal contraband, but also identify ceramic knives, explosives, etc. that cannot be identified by traditional security inspection methods.

[0032] 5. The present invention provides a detection method using a terahertz ground detection system for detecting the safety of the bottom of a vehicle, which solves the problem of rapid and accurate detection of dangerous items such as bombs in hidden places of vehicles that cannot be achieved by traditional technologies, and has the technical advantage of completely replacing other existing safety detection methods.

[0033] 6. The present invention provides a detection method using a terahertz ground detection system for detecting the safety of the bottom of a vehicle. The Raman spectrum database can be used for accurate detection to determine the composition of dangerous goods at the bottom of the target vehicle, thereby determining whether it is an explosive. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] In order to more clearly illustrate the technical solutions of the present invention or the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, what is described below is only one embodiment of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0035] Figure 1 A schematic diagram of the structure of a terahertz ground detection system for detecting the safety of the bottom of a vehicle provided by the present invention;

[0036] Figure 2 An imaging principle diagram of a terahertz ground detection system for detecting the safety of the bottom of a vehicle provided by the present invention;

[0037] Figure 3 A schematic diagram of the structure of a terahertz laser body of a terahertz ground detection system for detecting the safety of the bottom of a vehicle provided by the present invention;

[0038] Figure 4A schematic diagram of the structure of a terahertz detector body of a terahertz ground detection system for detecting the safety of a vehicle bottom provided by the present invention.

[0039] In the figure, 1- terahertz exciter body, 2- cylindrical mirror, 3- first convex lens, 4- first concave lens, 5- target vehicle, 6- polyethylene lens, 7- second concave lens, 8- second convex lens, 9- terahertz detector body, 10- computer, 11- near infrared emitter, 12- near infrared detector, 13- visible camera device, 14- glass. DETAILED DESCRIPTION

[0040] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0041] Embodiment 1:

[0042] See also Figure 1 , Figure 3 and Figure 4 , a terahertz ground detection system for detecting the safety of the bottom of a vehicle, comprising a terahertz exciter, a terahertz detector, a near-infrared detection system and a data processing system, wherein the terahertz exciter and the terahertz detector are both arranged underground, and the terahertz detector is connected to the data processing system;

[0043] The terahertz exciter excites and generates a terahertz wave signal, which is emitted to the target vehicle 5, and transmits the terahertz signal reflected by the bottom of the target vehicle 5 to the terahertz detector, and the terahertz detector generates terahertz spectrum information according to the terahertz signal reflected by the bottom of the target vehicle 5 and transmits the information to the data processing system for processing, and the data processing system processes the terahertz spectrum information, generates a corresponding relationship between the terahertz spectrum information and the unidentified object at the bottom of the target vehicle 5, forms an image and displays the result on the computer 10;

[0044] After the near infrared detection system detects the information of the target vehicle 5, the information is sent to the data processing system.

[0045] Preferably, the near infrared detection system includes a near infrared emitter 11 and a near infrared detector 12. The near infrared emitter 11 emits infrared rays to the target vehicle 5, and the infrared rays are reflected to reach the near infrared detector 12. The near infrared detector 12 transmits information to the data processing system and displays the results on the computer 10.

[0046] Preferably, it further comprises a visible camera device 13 , which works with a CCD chip. The information collected by the visible camera device 13 is transmitted to a data processing system, and the imaging result of the visible camera device 13 is displayed on the computer 10 .

[0047] Preferably, glass 14 is provided on the ground, the terahertz exciter emits terahertz waves at a certain angle, the terahertz waves pass through one glass 14 to reach the target vehicle 5, and the terahertz waves reflected and refracted by the target vehicle 5 pass through another glass 14 to reach the terahertz detector.

[0048] Preferably, the terahertz exciter includes a terahertz exciter body 1, a cylindrical mirror 2, a first convex lens 3 and a first concave lens 4, and the terahertz wave emitted by the terahertz exciter body 1 passes through the cylindrical mirror 2, the first convex lens 3 and the first concave lens 4 in sequence to reach the bottom of the target vehicle 5.

[0049] Preferably, the terahertz detector includes a polyethylene lens 6, a second concave lens 7, a second convex lens 8 and a terahertz detector body 9, and the terahertz wave reflected by the bottom of the target vehicle 5 passes through the polyethylene lens 6, the second concave lens 7 and the second convex lens 8 in sequence to reach the terahertz detector body 9.

[0050] Preferably, the data processing system is also used to receive terahertz spectrum information of an unknown vehicle, compare it with the correspondence between the terahertz spectrum information and an unknown object at the bottom of the vehicle, and display the result on the computer 10.

[0051] Preferably, it also includes a Raman detection system for analyzing the composition of dangerous goods at the bottom of the target vehicle 5 to determine whether they are explosives, and the Raman detection system includes a Raman spectrometer.

[0052] like Figure 2 As shown, the principle of the present invention is as follows: the terahertz exciter body 1 emits terahertz waves, at which time the terahertz waves are point light sources, which are transformed into line light sources through the cylindrical mirror 2, and then the line light sources are transformed into parallel light after passing through the first convex lens 3 and the first concave lens 4 and reach the bottom of the target vehicle 5. Then, the terahertz waves are reflected through the polyethylene lens 6, the second concave lens 7, and the second convex lens 8, and then become line light sources to reach the terahertz detector body 9, and then transmitted to the computer 10.

[0053] When the light is dark, especially at night, the near infrared transmitter 11 emits infrared rays to the target vehicle, and the infrared rays are reflected to the near infrared detector 12, and then the information is transmitted to the computer 10. It can be seen that the camera device 13 can more clearly detect the specific situation of the bottom of the vehicle.

[0054] Embodiment 2:

[0055] This embodiment provides a detection method using the terahertz ground detection system as described above, comprising the following steps:

[0056] S1. The terahertz wave emitted by the terahertz exciter is collimated and expanded, and the point light source of the terahertz laser is changed into a stable line light source, and then irradiated to the bottom of the target vehicle 5;

[0057] S2. The terahertz detector detects the terahertz wave reflected from the bottom of the target vehicle 5, and transmits it to the data processing system through the collection optical system;

[0058] S3. The data processing system analyzes the detection information of the target vehicle 5 at the bottom according to the detection data of the terahertz detector, and forms an image displayed on the computer 10;

[0059] S4. If the image in step S3 is an unidentified object, stop the target vehicle 5, detect the unidentified object with a Raman spectrometer, and analyze the composition of the dangerous goods at the bottom of the target vehicle 5 by comparing it with the terahertz reflection Raman spectrum database to determine whether it is an explosive.

[0060] Preferably, the steps S1 to S3 also include detection using a near-infrared detection system, and the near-infrared detection system includes a near-infrared emitter 11 and a near-infrared detector 12. The specific steps are: in the step S1, the near-infrared emitter 11 emits infrared rays to the target vehicle 5; in the step S2, the infrared rays are reflected to reach the near-infrared detector 12, and the near-infrared detector 12 transmits the information to the data processing system; in the step S3, the data processing system analyzes the detection information of the bottom of the target vehicle 5 according to the detection data of the near-infrared detector 12, and displays the results on the computer 10.

[0061] Preferably, the near infrared detection system is used for detection in a dimly lit environment.

[0062] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principle of the present invention. These improvements and modifications should also be regarded as the scope of protection of the present invention.

Claims

1. A terahertz ground detection system for detecting the safety of the bottom of a vehicle, characterized in that: It includes a terahertz exciter, a terahertz detector, a near-infrared detection system and a data processing system, wherein the terahertz exciter and the terahertz detector are both arranged underground, and the terahertz detector is connected to the data processing system; The terahertz exciter generates a terahertz wave signal, which is emitted to the target vehicle (5), and transmits the terahertz signal reflected by the bottom of the target vehicle (5) to the terahertz detector. The terahertz detector generates terahertz spectrum information based on the terahertz signal reflected by the bottom of the target vehicle (5), and transmits the information to the data processing system for processing. The data processing system processes the terahertz spectrum information, generates a corresponding relationship between the terahertz spectrum information and an unidentified object at the bottom of the target vehicle (5), and displays the result on a computer (10); After the near infrared detection system detects the target vehicle (5) information, the information is sent to the data processing system; Glass (14) is arranged on the ground, the terahertz exciter emits terahertz waves at a certain angle, the terahertz waves pass through one side of the glass (14) to reach the target vehicle (5), and the terahertz waves reflected and refracted by the target vehicle (5) pass through another side of the glass (14) to reach the terahertz detector; The terahertz exciter comprises a terahertz exciter body (1), a cylindrical mirror (2), a first convex lens (3) and a first concave lens (4); the terahertz wave emitted by the terahertz exciter body (1) passes through the cylindrical mirror (2), the first convex lens (3) and the first concave lens (4) in sequence and reaches the bottom of the target vehicle (5); The terahertz detector comprises a polyethylene lens (6), a second concave lens (7), a second convex lens (8) and a terahertz detector body (9); the terahertz wave reflected by the bottom of the target vehicle (5) passes through the polyethylene lens (6), the second concave lens (7) and the second convex lens (8) in sequence and reaches the terahertz detector body (9); It also includes a visible camera device (13), the visible camera device (13) uses a CCD as a chip to work, the information collected by the visible camera device (13) is transmitted to a data processing system, and the imaging result of the visible camera device (13) is displayed on a computer (10).

2. A terahertz ground detection system for detecting vehicle bottom safety according to claim 1, characterized in that: The near infrared detection system comprises a near infrared emitter (11) and a near infrared detector (12); the near infrared emitter (11) emits infrared rays to a target vehicle (5); the infrared rays are reflected and reach the near infrared detector (12); the near infrared detector (12) transmits information to a data processing system and displays the result on a computer (10).

3. The terahertz ground detection system for detecting the safety of the bottom of a vehicle according to claim 1, characterized in that: The data processing system is also used to receive terahertz spectrum information of an unknown vehicle, compare it with the correspondence between the terahertz spectrum information and the unknown object at the bottom of the vehicle, and display the result on a computer.

4. The terahertz ground detection system for detecting the safety of the bottom of a vehicle according to claim 1, characterized in that: It also includes a Raman detection system for performing component analysis on dangerous goods at the bottom of the target vehicle (5) to determine whether they are explosives, wherein the Raman detection system includes a Raman spectrometer.

5. A detection method using the terahertz ground detection system according to any one of claims 1 to 4, characterized in that: The following steps are involved: S1. The terahertz exciter emits a terahertz wave which is collimated and expanded to transform the point light source of the terahertz laser into a stable line light source, which is then irradiated onto the bottom of the target vehicle (5); S2. The terahertz detector detects the terahertz wave reflected from the bottom of the target vehicle (5), transmits it to the data processing system through the collection optical system; S3. The data processing system analyzes the detection information of the bottom of the target vehicle (5) according to the detection data of the terahertz detector, and forms an image to be displayed on the computer (10); S4. If the image in step S3 is an unidentified object, the target vehicle (5) is stopped, and the unidentified object is detected by a Raman spectrometer. By comparing it with the terahertz reflection Raman spectrum database, the dangerous goods at the bottom of the target vehicle (5) are analyzed for components to determine whether it is an explosive.

6. The detection method of the terahertz ground detection system according to claim 5, characterized in that: The steps S1 to S3 also include detection using a near-infrared detection system, wherein the near-infrared detection system includes a near-infrared emitter (11) and a near-infrared detector (12). The specific steps are as follows: in the step S1, the near-infrared emitter (11) emits infrared rays to the target vehicle (5); in the step S2, the infrared rays are reflected and reach the near-infrared detector (12), and the near-infrared detector (12) transmits information to a data processing system; in the step S3, the data processing system analyzes the detection information of the bottom of the target vehicle (5) based on the detection data of the near-infrared detector (12), and displays the result on a computer (10).

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