Human body safety scanner

Abstract

The disclosed invention includes a security check system and device for real-time detection and classification of items hidden on the body of a moving or stationary person and in carried or wheeled luggage. The present invention combines radio wave technology, magnetometer technology and optical sensors to detect dielectric and / or metallic objects on a target moving through the portal formed by the present invention. The sensed data is then sent to a computing processor of the system, which forms a two-dimensional image to determine the type of the object, the position of the object, and other additional information related to the target and / or object.

Description

TECHNICAL FIELD

[0001] The present invention relates to the security screening and detection of dielectric and metallic objects concealed on a person or in their luggage. BACKGROUND

[0002] The closest threat detection system to the present invention is the Rapiscan Systems Secure 1000 SP. The Secure 1000 SP uses backscatter technology along with image processing software and an operator interface to screen passengers for a wide range of potential threats, including liquids, contraband, ceramics, explosives, narcotics, concealed currency, and weapons. The Secure 1000 SP produces simultaneous front and back scans. The Secure 1000 SP can detect small objects and threats concealed on a passenger. It can detect organic and inorganic threats, metallic and non-metallic objects, and can detect concealed liquids, ceramics, weapons, plastic explosives, narcotics, metals, contraband, currency, etc. The Secure 1000 SP requires one pose, the passenger does not need to move extra, and a complete scan can be completed in a few seconds. The Secure 1000 SP bounces very low doses of x-rays off a person to generate an image. This image is then analyzed by an operator to identify concealed potential threats.

[0003] The limitations of the Rapiscan Systems Secure 1000 SP are that it requires a person to be in a single pose for scanning, it requires an operator to determine what threats exist and to view the scan image, it uses x-rays for scanning, it only performs backscatter and not through imaging, and it is designed to work at a security checkpoint, not in an array where it can scan multiple individuals and their luggage without creating a security hazard. The Rapiscan Systems Secure 1000 SP cannot detect radiological / nuclear materials.

[0004] There is a need for a low cost multi-threat detection system that has very short processing times, allowing for simultaneous detection of various threats. SUMMARY

[0005] The invention comprises a security screening device, system and method comprising: a portal comprising two side columns, preferably electrically connected with an overhead beam (i.e. an arch) or floor / underfloor cable conduit, the portal forming an inspection area, each of the two side columns comprising a linear array of two or more millimeter wave transmitters, preferably 16-256 millimeter wave transmitters; a linear array of two or more millimeter wave receivers, can also preferably comprise one or more magnetometers, one or more video cameras, a radio frequency generation, distribution and demodulation module, and a data acquisition processor and an imaging processor, the overhead beam (or a separate third column if there is no overhead beam) comprising a power input system and a computing processor, the transmitters transmitting a cyclic wideband radio wave signal to two or more of the receivers located on the opposite side column or on the same side column, the cyclic wideband radio wave signal being either an unimpinged direct signal (unimpinged direct signal) by a moving target moving within the inspection area, or a transmitted signal (transmitted signal) by a moving target moving through the inspection area, or a scattered signal reflected back (reflected back signal) after impinging a moving target moving through the inspection area, the receivers sending the sensed signal to a data acquisition processor and then to an imaging processor, the imaging processor providing one or more or more signals.

[0006] Based on the unimpinged direct signal or the transmitted signal and the reflected signal, the imaging processor further analyzes the sensed data to select one or more portions of the one or more two-dimensional images, the one or more portions corresponding to one or more detected hidden items of interest, the one or more magnetometers providing supplemental magnetic field data to the processor for the analysis, and the one or more video cameras tracking the hidden items of interest. BRIEF DESCRIPTION OF DRAWINGS

[0007] The invention is illustrated by the following drawings.

[0008] Figure 1 An example diagram of a portal according to the invention is shown.

[0009] Figure 2 An embodiment of the invention with an overhead beam is shown.

[0010] Figure 2A An embodiment of the invention without an overhead beam is shown.

[0011] Figure 3A schematic diagram showing an image obtained from a dielectric attached to a body in "reflective" mode. 21 - body; 22 - dielectric; 23 - transmitter; 24 - receiver; 25 - 2D image; 26 - selected pattern; A - radio waves reflected from the body; B - radio waves reflected from the body after passing through the dielectric; C - radio waves reflected from the dielectric.

[0012] Figure 4 A schematic diagram showing an image obtained from a dielectric attached to a body in "transmissive" mode. 21 - body; 22 - dielectric; 23 - transmitter; 24 - receiver; 25 - 2D image; 26 - selected pattern; D - radio waves passing above or below the dielectric; E - radio waves passing through the dielectric.

[0013] Figure 5 An example distribution of anomalies detected by the present invention for targets with objects of interest (lighter part of the histogram) and targets without any objects of interest (darker part of the histogram in the left part of the graph).

[0014] Figure 6 An example of a plot of the results of the passive magnetometry system of the present invention after a time scan of the three magnetic field components (Bx, By, Bz) from the sensors when a target with a magnetized object passes through the gantry of the device. The horizontal axis shows time in seconds, while the vertical axis shows the values of the magnetic field components in nanotesla (nT).

[0015] Figure 7 A software interaction diagram of the present invention is shown. DETAILED DESCRIPTION

[0016] Definitions:

[0017] This patent application relates to millimeter wave transmitters in the radiation range 0.3-300 GHz, and receivers that receive radiation in this range. The preferred range of operation is 10-20 GHz.

[0018] The invention is implemented in the form of a gantry structure having side columns 100 and optional overhead beams 110 connecting the side columns. The height of the gantry is 1.5-2.5 meters. The side columns each comprise a vertical linear array of transceiver antennas 101 (two or more millimeter wave transmitters), a vertical linear array of sensors 102 (two or more millimeter wave receivers) with corresponding electronics (e.g. radio frequency generation, distribution and demodulation modules 105, data acquisition processor 106, imaging processor 107), one or more magnetometers 104 and one or more video cameras 103, and the horizontal overhead beams (or floor ducts or third separate columns) comprise a power input system 108 and a computing processor 109.

[0019] The detection of hidden items 22 hidden on the moving targets by the device is based on at least one or a combination of two techniques:

[0020] 1. The dielectric object detection is performed via active sensing using coherent radiation with continuously varying frequency in the range of 5-20 GHz as each target moves through the opening created by the device. The transmitted cyclical broadband radio wave signals are varied in time, in frequency or in both time and frequency. By this radiation and variation, the device of the invention forms a computer image of the moving targets / individuals and the associated dielectric objects located on or near the target bodies. The system performing this function is referred to herein as the microwave dielectric detection (MDD) subsystem of the invention. This system performs the detection of hidden items with an optical path length of 2-20 cm hidden on the moving targets. The optical path length (OPL) in a medium with constant refractive index "n" is equal to "ns", where "s" is the geometric length.

[0021] Optionally, the transmitters are positioned on a vertical line with equal spacing between each other and the receivers are positioned on a vertical line with equal spacing between each other.

[0022] The transmitters transmit the broadband radio wave signals with one linear polarization or two orthogonal polarizations and the receivers induce the broadband radio wave signals with one linear polarization or two orthogonal polarizations.

[0023] The sensed signals are received by a data acquisition processor which creates an image stream from the sensed data. The data acquisition and imaging processor provides the separation of the phase of the cyclical broadband radio wave signals. The imaging processor provides a cross-eyed image of the target based on the positions of the transmitters and receivers on both sides of the inspection area.

[0024] 2. Passive magnetic force measurement (PM) is implemented together with the microwave dielectric detection subsystem for the purpose of complementing the detection of metal objects with residual magnetization. The system performing this function is referred to herein as the passive magnetometer (PM) subsystem of the present invention.

[0025] In addition to these two technologies, the tracked object detection is performed by a third technology, which includes a camera subsystem designed to provide video fixation of the target / individual once the alarm of the detection of a concealed object occurs. The processor processes and analyzes the optical image stream. The processing includes classification of each target based on joint analysis of optical data, magnetometer data, and radio wave data.

[0026] Structural composition of the device.

[0027] Figure 1 A functional diagram of the device of the present invention is shown. Each side column accommodates MDD subsystem components (transmit and receive antennas, data processing board, FPGA chip board) and PM subsystem components. Each side column also accommodates two video cameras and a computer mounted on the column, which performs some data processing and data acquisition operations, respectively. The arch / gantry includes an arch computer, which is responsible for final data processing operations. The arch / gantry also includes an auxiliary module, which includes power supply and network components. The side columns are connected to the arch through connectors, which provide data exchange between the arch and each side column and between the two side columns. If the gantry / arch is not used, the side columns can be connected, for example, via floor / underfloor cable ducts. The cable ducts can also accommodate computing processors and / or power input systems.

[0028] MDD subsystem.

[0029] The MDD subsystem includes a low-power radar system with an inverse synthetic aperture (ISAR - inverse synthetic aperture) aperture, which uses the motion of the target instead of the transmitter to produce a synthetic aperture (see, for example, Grishin Yu.P., Ipatov V.P., et al. "Radiotechnical Systems", edited by Yu.M. Kazarinov, 1990).

[0030] Each side column of the inventive device contains a vertical linear array of 16-128 transmitting antennas and 1-128 receiving antennas, all of which are uniformly distributed along the height of each side column of the device. After analyzing the received signals (direct and reflected signals from objects and targets within the detection area), a planar 2-D image in the height and range coordinates of the inspection area is formed. The distance values are determined from the analysis of the broadband signals, and the height values are determined from the analysis of the signals emitted by the vertical lines of transmitting antennas. The system has no horizontal axis resolution and assumes that there is one person in the inspection area at a time. The signal processing is performed using "fast time" and "slow time" Fourier transforms and window filters according to the "inverse synthetic aperture" algorithm on the FPGA chip.

[0031] The receiving and transmitting antennas of the inventive device are made of planar technology and provide the required characteristics in the frequency range of 10-20 GHz. The radiated power of the entire device is kept around -40 dBm.

[0032] The MDD subsystem operates in two modes:

[0033] 1. Reflection mode of radio waves;

[0034] 2. Transmission mode of radio waves.

[0035] The reflection mode is based on the fact that the human body is almost a perfect reflector of radio waves in the frequency range used. If there is a dielectric item against the body in the path of the radio waves, a part of the wave is reflected from the front surface of the dielectric, and a part of the wave passes through the dielectric and is then reflected from the body. See Figure 3 which shows the operating principle of the reflection mode, and the generated example image. In the example image, on the horizontal axis is the distance traveled by the wave, and on the vertical axis is the number of the transmitter in the vertical scale.

[0036] In the reflection mode, there is a delay in the arrival of the reflected wave at the receiver due to the fact that the speed of propagation of the radio wave in the dielectric is less than the speed of light in air. This lag is interpreted as an additional path taken by the wave before reflection, and thus the image of the back surface of the dielectric is "pressed" into the image of the surrounding body. Figure 3 The example generated image shows the area of wave reflection from the front and back surfaces of the dielectric on the belt. Above and below this area there is only one reflecting surface: the top of the torso and part of the front leg. Therefore, the fact that there are front and back dielectric surfaces in the microwave image is interpreted as an anomaly.

[0037] The transmission mode is based on the fact that when radio waves travel through a dielectric object from a transmitter on one side of a column to a receiver on the other, the apparent path length of the wave increases due to its slower propagation through the dielectric (see [link to original text]). Figure 4 (Left side). This causes the image in the dielectric region to shift to the right into the region of the longer path (see left side). Figure 4 (On the right side). Figure 4 The left side of the image illustrates the operating principle of the "through" mode. Figure 4 The right side shows an example image of a person with a dielectric material on their body. The horizontal axis represents the distance the wave travels, and the vertical axis represents the transmitter number based on the height of the side pillars. Therefore, the detection of a right-shifted portion of the image within the microwave image is interpreted as an anomaly.

[0038] The abnormal reflections obtained from the equipment are further gathered as the moving target passes through the entire inspection area, and the resulting data is used to issue an overall detection signal / alarm.

[0039] When the target moves through the inspection area at a speed of 1-3 m / s, the equipment searches for the person in the following order:

[0040] When a target approaches the plane of the device and transmitter-receiver, the front of the main body is shielded using a reflection mode;

[0041] When the target crosses the initial plane of the transmitter-receiver, the front of the main body is shielded using the transmission mode;

[0042] Before the target passes through the final plane of the transmitter-receiver, the rear of the main body is shielded using the transmission mode;

[0043] After the target passes through the initial plane of the transmitter-receiver, a reflection mode is used to shield the rear of the subject;

[0044] When the target remains within the transmitter-receiver plane, the side portions of the main body are shielded using a reflection mode.

[0045] Since there are two transmitter-receiver planes in the system (transmitter left + receiver right, transmitter right + receiver left), the above test sequence occurs twice simultaneously (i.e., once on each side).

[0046] The wavelength of the emitters is about 30 mm. In order to effectively select the part of the moving person, the radiation phase correlation is required, which means that during the scan, the part of the human body should not move more than a few millimeters. Therefore, the scan period should not exceed a few ms, for example, the scan period is 2 ms. If the number of emitters is 128, then 1 emitter should generate a signal with a duration of about 20 μβ. In order to achieve the required image contrast, which corresponds to the required path length resolution of 1-3 mm, the bandwidth of the cyclic emitter signal must be 5-10 GHz. This means that one emitter must scan the specified range of 10 GHz in 20 μβ. The linear chirp method is best suited to solve this problem.

[0047] The received signal must be digitized and processed. Using a two-dimensional Fourier transform, the choice of the processor imposes a limitation. An FPGA (Field Programmable Gate Array) is chosen, which allows to receive digitized data in a pipeline mode, to process it at the same bit rate and to transfer the already prepared image to the next processor.

[0048] The next processor provides a confidence value corresponding to the detected hidden item of interest and a digital representation corresponding to said detected hidden item.

[0049] In general, the number of anomalies obtained during the passage of a target including a dielectric object on the body (i.e. the length of the track obtained) will significantly exceed the number of anomalies obtained during the passage of a target not including a dielectric object (see Figure 5 ). When passing without a dielectric object on the body, the device should generally detect no more than two anomalies during the entire passage time. In contrast, when a target with a dielectric object passes through the device, up to 20 anomalies can be detected. Figure 5 An example distribution of the length of the track of the anomalies detected during the passage of a target without a dielectric object on the body (dark part of the histogram in the left part of the graph) and a target with a dielectric object tied to its leg (e.g. plasticine) (lighter part of the histogram) is shown.

[0050] PM subsystem.

[0051] The device of the invention also comprises a passive magnetometer subsystem, which allows to detect objects with residual magnetization. The PM subsystem comprises, for example, 20 (10 per side column) 3-axis MagDRV type magnetic field sensors positioned along the side columns, and 4 MagDAQ boards serving the magnetic field sensors (i.e. digitization and power supply boards of the sensors).

[0052] The passive magnetometric technique is based on the fact that the digitized instantaneous values of the magnetic field along three mutually perpendicular axes in the position of the sensor completely determine the magnetic field vector B in these points.

[0053] Figure 6 An example of a time scan of the three magnetic field components (Bx, By, Bz) from one of the sensors is shown when a target with a magnetized object passes through the portal of the device. The horizontal axis shows time in seconds, while the vertical axis shows the values of the magnetic field components in nanotesla (nT).

[0054] After subtracting the constant component of the magnetic field (i.e. the Earth's magnetic field), the PM subsystem determines the magnetic field produced by the magnetized object located nearby, which in the first approximation can be considered as a point magnetic dipole with a magnetic moment m.

[0055] When the target with a magnetized object passes through the portal, the values of the measured magnetic field first increase and then decrease (as shown in Figure 6 The distribution of the field values between the components Bx, By and Bz depends on the position of the magnet, its strength and the orientation of its dipole moment in space.

[0056] The magnetic field B produced by a magnetic dipole m at a distance r in the direction determined by the unit vector n is given by the formula B(r) = [3n(n,m) - m] / r 3 (see, for example, Jackson J.D. Classical Electrodynamics, 2nd edition, John Wiley & Sons, New York, 1975, p. 182).

[0057] In the PM subsystem of the invention, the field B is measured at a large number of points (i.e. at the positions of the sensors). Then, the inverse problem of determining the coordinates (x, y, z) and the dipole moment components (mx, my, mz) that can cause such a magnetic field is solved numerically / mathematically. Finally, if the value of the calculated vector m exceeds a threshold value, an anomaly is generated and further processed in the same way as the anomalies obtained from the MDD subsystem. This further processing is discussed below.

[0058] Data processing algorithm and software composition

[0059] The data processing and the principle of the received signal with respect to the detection of objects of interest (i.e. anomalies) are as follows.

[0060] 1. In the first stage, there is a screening for anomalies, which is a manifestation of the presence of objects of interest detected by the MDD subsystem or the PM subsystem.

[0061] 2. Then, each type of anomaly is collected into separate groups to create trajectories with length that are collections of similar anomalies of a given type from adjacent consecutive frames.

[0062] 3. Finally, if at any point the trajectory length reaches a threshold, an alert is issued signaling the detection of an object of interest.

[0063] The software of the prototype consists of four separate programs, working under the Linux open source OS, and having the following functions:

[0064] 1. hss_pfdev: provides microwave images from the system.

[0065] 2. hss_rfpipeline: detects anomalies from the microwave images.

[0066] 3. hss_gspipeline: acquires video images from the video cameras.

[0067] 4. hss_server: receives anomalies using the PM subsystem, aggregates all received anomalies into trajectories, and issues detection signals.

[0068] The programs hss_pfdev, hss_rfpipeline and hss_gspipeline run on the embedded computers installed on the side columns, and the program hss_server runs on the arch computer. The software interaction diagram is shown in Figure 7 . The software is pre-installed on the device as an executable file, and it automatically starts at power-up.

[0069] The present invention generally comprises:

[0070] 1. A system and device for real-time detection and classification of items hidden on the body of a moving or stationary person and in carried or wheeled luggage. It is also possible to exploit the following technologies:

[0071] - Wideband radio wave signals are cyclically scanned over the inspection area by a plurality of fixed distributed transmitters. Scattered and direct wideband radio wave signals are received by a set of fixed distributed receivers. Transmitters / emitters and receivers / sensors are positioned on each of two side columns which are connected via a catwalk (i.e. an arch). This structure forms a gantry comprising two side columns electrically connected with the catwalk, which thus forms the inspection area. Each of the two side columns comprises a linear vertical array of 16-124 millimeter wave emitters and 8-124 millimeter wave receivers, one or more magnetometers, and two or more video cameras. The system further comprises a power input system and a computing processor. The emitters emit cyclic wideband radio wave signals towards the inspection area, and the receivers sense the wideband radio wave signals after they are emitted through a target and / or any object or scattered by a target and / or any object. The wideband radio wave signals are either unimpinged direct signals or scattered signals that have been redirected or otherwise impinged after impinging movement through the target of the inspection area. The receivers then send the sensed data to the computing processor, which then provides one or more two-dimensional images of the target based on the unimpinged direct signals and the scattered signals. The computing processor also analyzes the sensed data to select one or more portions of the one or more two-dimensional images that correspond to a detected hidden item of interest. One or more magnetometers provide supplemental magnetic field data to the processor for the analysis, e.g., for further confirmation of the item of interest. The one or more video cameras provide tracking of the hidden item of interest that can even extend beyond the inspection area. Additional optical sensors can also be utilized in the apparatus;

[0072] - A set of two-dimensional images of a human target and baggage are drawn based on scattered and direct radio wave signals;

[0073] - Radio wave image streams with selected image portions corresponding to hidden objects (anomalies) are analyzed and their characteristics are obtained;

[0074] - Characteristics of moving or stationary humans or objects obtained as a result of the above analysis are supplemented with data from other sensors such as magnetometers, optical sensors (video cameras, stereo cameras, depth sensors, presence sensors in the area, etc.);

[0075] - Objects are classified based on a set of characteristics of the objects.

[0076] The system and apparatus further allow embodiments that include, among others, the following options.

[0077] 1. Cyclic scanning of the period time of millimeter range radio waves signals with millisecond wide band (with bandwidth of 1 GHz to 10 GHz), where the examination area is given frequency switching by many fixed transmitters pairs.

[0078] 2. Cyclic scanning with transmitters separation:

[0079] including time division of the transmitters,

[0080] including transmitters separated by frequency or

[0081] combination of both methods.

[0082] 4. Cyclic scanning with transmitters placement includes:

[0083] full height (height), adjacent, about 1.5-2.5 m, or

[0084] height steps, equidistantly spaced and positioned few centimeters (i.e. 2-3 cm) apart from each other.

[0085] Thus, the linearity of the device - with minimal spacing and minimal number of full heights (cyclic time requirements).

[0086] The transmitters are located at different sides of the human movement area, to obtain cross-sectional images from different perspectives (aperture synthesis, in X-Y axes) - "gantry" configuration.

[0087] 5. Cyclic scanning in one or both orthogonal polarizations of the radio waves signals (co-polarization and cross-polarization).

[0088] The image stream is multi-channel, with the following options:

[0089] 1) For example, if one polarization is utilized (the image can be represented as a color image in some color encoding scheme (e.g. HSV)), where:

[0090] a) Channel A: provides data as luminance gradient based on the characteristics of the received scattered or transmitted signal;

[0091] b) Channel B: provides data based on the characteristics of the moving speed of the targets / scatterers of the signal;

[0092] 2) If two orthogonal polarizations are utilized (the image can be represented as a color image or as a set of images in some color encoding scheme (e.g. RGB)), where:

[0093] a) Channel A: provides data as luminance gradient based on the characteristics of the received scattered or transmitted signal;

[0094] b) Channel B: provides data based on the characteristics of the moving speed of the targets / scatterers of the signal;

[0095] c) Channel C: provides data as co-linear vertical polarization based on the characteristics of the received scattered or transmitted signals;

[0096] d) Channel D: provides data as cross-line polarization based on the characteristics of the received scattered or transmitted signals;

[0097] e) Channel E: provides data as co-linear horizontal polarization based on the characteristics of the received scattered or transmitted signals.

[0098] 6. Receive scattered and direct wideband radio wave signals.

[0099] When a person and baggage (moving target) moves through the inspection area, a plurality of fixed receivers located on different sides of the area of human movement form an image stream.

[0100] 7. Receive scattered and direct wideband radio wave signals, where the phase of these signals is separated (coherent signal reception method).

[0101] 8. Receive scattered and direct wideband radio wave signals in two orthogonal polarizations of radio wave signals (co-polarization and cross-polarization).

[0102] 9. Receive scattered and direct wideband radio wave signals by positioning of the receivers:

[0103] Full height (height), adjacent, about 1.5-2.5 m, or

[0104] Height step, equidistantly spaced from each other by a few centimeters (i.e. 2-3 cm).

[0105] 10. Construct a set of two-dimensional images of the human body and baggage based on scattered and direct radio wave signals, where the positions of the transmitters and receivers are located on different sides of the area of human movement, when each pillar contains a receiver and a transmitter, oblique view images can be obtained from different perspectives.

[0106] 11. Analyze a plurality of two-dimensional images of the human body and baggage based on scattered and direct radio wave signals, select image parts corresponding to hidden objects (anomalies), for example:

[0107] - includes searching for patterns (anomalies) in images or image streams (detection);

[0108] - includes using image areas containing patterns / anomalies of interest (segmentation);

[0109] - includes using the location of anomalies of interest in a series (stream) of images (tracking);

[0110] - including when the anomaly of interest is a combination of the brightness and color of an image region, including when the brightness of an image region corresponds to the intensity of the scattering in that region, and the color of the region corresponds to the speed and direction of movement of the objects in that region;

[0111] - including using information about the position of the anomalies detected in the image, in the form of the coordinates (in pixels) of the corners of the rectangle containing them (ROI - Region of Interest) or of the coordinates of one of their corners, width and height, and the confidence in the correctness of the finding pattern;

[0112] - including adding additional information obtained from the analysis of the microwave image (features) to the information about the position of the anomaly and the confidence in the correctness of the finding of the anomaly;

[0113] - including forming for each anomaly a digital array containing a digital representation of this information;

[0114] - including when this additional information is obtained by calculating at least one of the following image characteristics: maximum and / or minimum, average, median, standard deviation of brightness and / or speed;

[0115] - including when determining such features, including the entire region (ROI) of the anomaly, and / or regions within the interior, exterior and individual parts of the ROI, including the left, right, top, bottom, middle, above, below, left of the ROI, right of the ROI within the image region, the dimensions of the image region being preset as parameters (in number of pixels by width and / or height) or determined as a specified proportion of the width and / or height of the ROI according to the size and / or position of the ROI.

[0116] 12. Analysis of optical image streams (cameras, stereo pairs, TOF...), for example:

[0117] - including searching for objects (detection) in the image or image stream;

[0118] - including identifying the type of objects in the image, such as people, body parts, carried luggage, wheeled luggage, animals, etc.

[0119] - including including a marked region (segmentation) containing the image of the identified object;

[0120] - including tracking the position of the object of interest in a series (stream) of images (tracking);

[0121] - including obtaining additional information about the movement of people and / or objects, their position, speed, number, type, etc. by the system;

[0122] - including when this additional information is obtained from the analysis of video images;

[0123] - including when this additional information is tracking parameters of a moving object;

[0124] - including when this additional information is tracking parameters of a moving object;

[0125] - including when such a trajectory to a specific person and / or object is generated from a digital representation of such information.

[0126] 13. Using a plurality of fixed fluxgate magnetometers located on different sides of the area of movement of a person to continuously monitor distortions of the earth's magnetic field as the person and baggage move through the screening area to obtain additional information about magnetized objects on the person and in the baggage in the screening area, for example:

[0127] - including using single-axis and / or dual-axis and / or tri-axial magnetometers;

[0128] - including using fluxgate magnetometers;

[0129] - including detecting the presence of magnetized objects on the person or in the baggage;

[0130] - including using the fact that magnetized objects are present on the person or baggage as an indication that a firearm or cold steel can be present;

[0131] - including forming a track of such indicia as the person passes through the system.

[0132] 14. Combining track data from radio image analysis, optical image analysis and magnetometer data, for example:

[0133] - including joint analysis of tracking parameters of a moving object derived from analysis of radio images from one side or different sides of the gantry;

[0134] - including joint analysis of tracking parameters of a moving object obtained from analysis of optical images from one side or different sides of the gantry;

[0135] - including joint analysis of parameters of radio and optical images of a moving object obtained from the same or different sides of the gantry;

[0136] - including joint analysis of parameters of radio and optical images of a moving object obtained from one side or different sides of the gantry, and adding track parameters obtained from analysis of magnetometer data;

[0137] - including forming a digital array of parameters characterizing the track of a moving object ("passage"), taking into account the joint analysis described above, in which in each position of the array there is a number characterizing a fixed parameter (feature).

[0138] 15. Using the digital array containing the results of joint analysis to classify the track of a moving person ("pass"), for example:

[0139] - a method comprising a binary classification of the classes of passages of interest and passages of non-interest;

[0140] - a method comprising a classification into more than two classes of passages, with at least one class of passages of interest and at least one class of passages of non-interest;

[0141] - a method comprising an output of a signal about a passage belonging to a certain class;

[0142] - a method comprising an emission of an acoustic signal, a light signal, an image (photo, video stream) of a person or detected object with the frame superimposed on it, or any combination of the above signals;

[0143] - a method comprising an output of an image of a person or detected object with the frame superimposed on it, the color, the line thickness, the type of filling, the shape or any combination thereof corresponding to the class of the detected object according to predefined or configurable matching rules;

[0144] The invention can comprise any one or more of the following radiation methods:

[0145] Linear frequency scan (defined as a scan up) from 10 GHz to 20 GHz in a time of 16 μs and a scan back (scan down); the transmitter on one side of the gantry is only on when the scan is going up; the transmitter on the other side of the gantry is only on by scanning down;

[0146] The transmitter on the other side of the gantry is only on by scanning;

[0147] The transmitter on the other side of the gantry is only on by scanning down.

[0148] The reception methods include, but are not limited to:

[0149] High frequency mixer - feeding a reference (transmitted) signal and the amplitude of the measured frequency, phase and beat after the mixer.

[0150] The processing methods include, but are not limited to:

[0151] Fourier scan by frequency - obtaining the distance from the transmitter to the scattering point plus the distance from the scattering point to the receiver; Fourier per frame - obtaining the rate of change of phase at each scattering point; finding the maximum of the second order Fourier - determination of the speed of the object;

[0152] Correction procedure - geometric accounting forms a 2x dimensional image panel (for each receiver and each side of the gantry);

[0153] Images are obtained from their side and from the opposite side.

[0154] In essence, the invention thus comprises:

[0155] A security checkpoint apparatus comprising: a power input system, a computing processor, and a gantry, the gantry comprising two electronically connected side columns, the gantry forming an inspection area, each of the two side columns comprising a linear array of two or more millimeter wave transmitters, a linear array of one or more millimeter wave receivers, one or more magnetometers, and one or more video cameras, the two or more millimeter wave transmitters emitting a cyclical broadband radio wave signal toward the inspection area, the one or more receivers sensing the cyclical broadband radio wave signal emitted by the two or more millimeter wave transmitters as either an unimpinged direct signal or a scattered signal after impinging upon a target passing through the inspection area, the receivers sending the sensed data to the computing processor, the computing processor providing one or more two-dimensional images of the target based on the unimpinged direct signal and the scattered signal, the computing processor further analyzing the sensed data to select one or more segments of the one or more two-dimensional images corresponding to a detected hidden item of interest, the one or more magnetometers providing supplemental magnetic field data to the computing processor for the analysis, and the one or more video cameras tracking the hidden item of interest.

[0156] In some aspects, the transmitted cyclical broadband radio wave signal has a bandwidth of 5-20 GHz, the transmitted signal varying in frequency.

[0157] In some aspects, the transmitted cyclical broadband radio wave signal varies in time, in frequency, or in both time and frequency.

[0158] In some aspects, the transmitters are positioned on a vertical line and have equal spacing between each other, and wherein the receivers are positioned on a vertical line and have equal spacing between each other.

[0159] In some aspects, the transmitters emit and the receivers sense the cyclical broadband radio wave signal in one orthogonal polarization.

[0160] In some aspects, the processor creates a stream of images from the sensed data.

[0161] In some aspects, the processor provides a separation of the phase of the cyclical broadband radio wave signal.

[0162] In some aspects, the gantry has a height of 1.5-2.5 meters.

[0163] In some aspects, the processor provides an oblique view image of the target based on the locations of the transmitters and receivers on either side of the inspection area.

[0164] In some aspects, the analysis further comprises providing a confidence value corresponding to the detected hidden item of interest.

[0165] In some aspects, the analysis further comprises providing a digital representation corresponding to the detected hidden item of interest.

[0166] In some aspects, the analysis further comprises optical image stream analysis.

[0167] In some aspects, the analysis further comprises providing one of two or more classifications for each target based on a joint analysis of optical data, magnetometer data, and radio wave data.

[0168] In some aspects, the gantry further comprises a catwalk connecting the two side columns, the catwalk housing, the power input system, and the computing processor.

[0169] In some aspects, each of the side columns further comprises a radio frequency generation, distribution, and demodulation module and a data acquisition processor.

[0170] In some aspects, each of the two side columns comprises 16-128 of the millimeter wave transmitters.

[0171] In some aspects, the two side columns are electrically connected via a floor cable conduit.

[0172] In some aspects, the transmitters transmit and the receivers sense the wideband radio wave signals in two orthogonal polarizations.

[0173] A final benefit of the present invention is a significant reduction in implementation cost of the security inspection system. Unlike prior art square transmitter arrays that provide a complete 3-D image of the inspection area, the linear transmitter array used in the present invention provides a sufficient 2-D image. In the 2-D image, the horizontal axis corresponds to the distance traveled by the radio waves from the transmitters to the targets / scatterers and from the targets / scatterers to the receivers, and the vertical axis corresponds to the vertical coordinates of the targets / scatterers. Since the linear transmitter array contains fewer elements than the prior art square array, the cost of the system is reduced.

[0174] Another resulting benefit of the present invention is its ease of assembly. The side columns of the present invention are connected to the catwalk or floor cable conduit via composite connectors that allow for simple snap assembly and disassembly of the entire device / system.

[0175] The description of the preferred embodiments of the application has been presented for purposes of illustration and description. It is not intended to be exhaustive or to limit the application to the precise form disclosed. Obviously, many modifications and variations are possible in light of the above teachings. It is intended that the scope of the application be limited not with this detailed description.

[0176] Furthermore, the word "example" or "exemplary" is used herein to mean serving as an example, instance, or illustration. Any aspect or design described herein as "exemplary" is not necessarily to be construed as preferred or advantageous over other aspects or designs. Rather, the word "example" or "exemplary" is used herein to present concepts in one or more particular ways as examples or illustrations. The term "or" as used herein is intended to mean an inclusive "or" rather than an exclusive "or." That is, unless specified otherwise, or clear from context, "X employs A or B" is intended to mean any of the natural inclusive permutations. That is, if X employs A; X employs B; or X employs both A and B, then "X employs A or B" is satisfied under any of the foregoing instances. In addition, the articles "a" and "an" as used in this specification generally are not limiting, unless otherwise indicated or clear from context. Accordingly, the terms "a" and "an" are used herein to mean "one or more."

[0177] The application and the accompanying claims should not be construed as being limited to a single form unless expressly stated to be such.

Claims

1. A security inspection apparatus 2 and 2a comprising: a portal 1 comprising two electronically connected side columns 100, said portal forming an inspection area 120, each of said two side columns comprising a linear array of two or more millimeter wave transmitters 101, a linear array of two or more millimeter wave receivers 102; said two or more millimeter wave transmitters transmitting cyclic broadband radio wave signals towards said inspection area, searching for concealed items 22 hidden on a moving target 21, said moving target moving within said inspection area at an average speed of up to 5 m / s; each transmitter from said transmitter linear array cyclically scanning a range of 5-20 GHz within 10-50 microseconds; said one or more receivers sensing said cyclic broadband radio wave signals transmitted by said two or more millimeter wave transmitters, said cyclic broadband radio wave signals being direct signals not impacted by the moving target, signals transmitted through said moving target and signals reflected back after impacting said moving target; said one or more receivers transmitting the sensed signals to a data acquisition processor 106 and then to an imaging processor 107, said imaging processor providing one or more two-dimensional images 25 of said moving target based on processing of said direct signals not impacted or said transmitted signals and said reflected signals; said one or more two-dimensional images having an optical path length resolution better than 2 cm; said imaging processor 107 selecting one or more portions of said one or more two-dimensional images, said one or more portions corresponding to detected concealed items of interest.

2. The apparatus of claim 1, wherein, said transmitted cyclic broadband radio wave signals vary in time, in frequency or in both time and frequency.

3. The apparatus of claim 1, wherein, said transmitters are positioned on a vertical line and have equal spacing between each other, and wherein said receivers are positioned on a vertical line and have equal spacing between each other.

4. The apparatus of claim 1, wherein, said transmitters transmit said cyclic broadband radio wave signals in one linear polarization and said receivers sense said cyclic broadband radio wave signals.

5. The apparatus of claim 1, wherein, said imaging processor creates a stream of images from said sensed data.

6. The apparatus of claim 1, wherein, said imaging processor provides separation of phases of said cyclic broadband radio wave signals.

7. The apparatus of claim 1, wherein said imaging processor provides an oblique view image of said target based on positions of said transmitters and said receivers on both sides of said inspection area.

8. The apparatus of claim 1, further comprising one or more magnetometers 104; said one or more magnetometers providing supplementary magnetic field data to said computing processor for said processing.

9. The apparatus of claim 1, said analysis further comprising providing a confidence value corresponding to the detected concealed item of interest.

10. The apparatus of claim 1, said processing further comprising providing a digital representation corresponding to said detected concealed item of interest.

11. The apparatus of claim 1, further comprising one or more video cameras 103 that track the hidden item of interest.

12. The apparatus of claim 11, the processing further comprising optical image stream analysis, the processing further comprising providing one of two or more classifications for each target based on joint analysis of optical data, magnetometer data, and radio wave data.

13. The apparatus of claim 1, the gantry further comprising a high bay connecting the two side columns, the high bay housing a power input system and the acquisition processor.

14. The apparatus of claim 1, each of the side columns further comprising a radio frequency generation, distribution, and demodulation module 105 and a data acquisition processor 106 and imaging processor 107.

15. The apparatus of claim 1, wherein each of the two side columns comprises 16-256 of the millimeter wave transmitters, wherein the transmitters transmit and the receivers sense the circular wideband radio wave signals in two orthogonal polarizations.

Images