TECHNICAL FIELD

[0001] The present disclosure relates to through-the-wall imaging. More particularly, the present disclosure relates to an antenna array, an imaging device, a system, and a method for through wall imaging with interference removal along with good pixel intensity and reduced scanning time.

BACKGROUND

[0002] Through Wall Imaging (TWI) is an emerging technology, allowing to“seeing” through visually opaque material such as walls. Electromagnetic (EM) waves with frequencies of few Gigahertz’s are able to penetrate through almost all types of walls around us such as brick wall, plywood, plastic etc. Through-the-wall-imaging (TWI) can be used to detect objects inside an enclosed structure from the outside. In TWI, a transmitter emits an electromagnetic (EM) radar pulse, which propagates through a wall. The pulse is reflected by the objects on the other side of the wall, and then propagates back to a receiver as an impulse response convolved with the emitted pulse.

[0003] Typically, the transmitter and receiver use an antenna array. Depending on a dielectric permittivity and permeability of the wall, the received signal is often corrupted with indirect secondary reflections from the all, which result in ghost artifacts in an image that appear as noise. Wall clutter reduction techniques attempt to eliminate the artifacts that arise from the multi-path reflections TWI.

[0004] Till now the availability of the portable TWI system is based on A-Scan

(implementation of B- and C-scan in real time is in progress). Several algorithms based on signal processing, image processing, classical approaches have been developed for detection purpose. But, the conventional solutions fails to provide a cost effective and portable system which has very less scanning time along with detection and identification capability of various types of living and non-living targets. Further, the conventional approaches fail to deal with problem of interference or noise among the transmitted and received signals, and thereby compromise on quality of image and identification of targets. [0005] The present invention avoids the problems/disadvantages noted above and overcome other problems encountered in conventional methods. The objects, advantages and novel features of the invention may be realized and obtained by means of the instrumentalities and combinations particularly pointed out in the detailed description.

OBJECTS OF THE PRESENT DISCLOSURE

[0006] Some of the objects of the present disclosure, which at least one embodiment herein satisfies are as listed herein below.

[0007] It is an object of the present disclosure to overcome problems associated with the conventional prior art.

[0008] It is an object of the present disclosure to provide an antenna array, an imaging device, and a system for through wall imaging with interference removal along with good pixel intensity.

[0009] It is an object of the present disclosure to provide a prototype of through wall imaging that has the capability to detect and identify the targets behind the wall.

[00010] It is an object of the present disclosure to provide antenna array which is portable, compact, and is of light weight.

[00011] It is an object of the present disclosure to provide good range resolution and cross range resolution that can be used for imaging a target behind the wall.

[00012] It is an object of the present disclosure to provide a solution wherein scanning time to image the target is reduced by introducing the concept of array antenna. In an example, scanning time may be 5-10 seconds for a i m length of wall or any other obstruction.

[00013] It is an object of the present disclosure to provide a solution wherein crosstalk in the antenna array is minimized by the coating of developed microwave absorber, which improved the image quality.

SUMMARY

[00014] The present disclosure relates to through-the-wall imaging. More particularly, the present disclosure relates to an antenna array, an imaging device, and a system for through wall imaging with interference removal along with good pixel intensity and reduced scanning time. [00015] According to an aspect of the present disclosure, an antenna array for through wall imaging includes a plurality of antennas configured to transmit and receive a plurality of signals to and from, respectively, a plurality of targets across an obstruction; and a plurality of interference restricting elements interposed between the plurality of antennas, wherein the plurality of interference restricting elements are configured to reduce interference of the plurality of signals among the plurality of antennas based upon microwave absorption.

[00016] In an embodiment, the plurality of interference restricting elements is a microwave absorber coated aluminum sheet.

[00017] According to another aspect of the present disclosure, a portable imaging device for through wall imaging includes an antenna array; a transceiver unit communicably coupled to the antenna array; and a control unit communicably coupled to the antenna array and the transceiver unit, wherein, the antenna array includes a plurality of antennas configured to transmit and receive a plurality of signals to and from, respectively, a plurality of targets across an obstruction; and a plurality of interference restricting elements interposed between the plurality of antennas, wherein the plurality of interference restricting elements are configured to reduce interference of the plurality of signals among the plurality of antennas based upon microwave absorption.

[00018] In an embodiment, the control unit is configured to control transmitting, receiving, and real time processing of the plurality of signals of the antenna array.

[00019] In an embodiment, the transceiver unit operates in a frequency range of 1.5GHz- 3.5GHz.

[00020] According to another aspect of the present disclosure, a through wall imaging system configured for a delay based scanning for reconstructing a scene based upon identification of a plurality targets behind an obstruction includes a hardware processor; and a machine-readable storage medium storing instructions that, when executed by the hardware processor, cause the hardware processor to receive an input from an imaging device; estimate parameters of the obstruction based on processing of the input; generate a model of permittivity of the obstruction using the parameters; classify the targets based upon the model; and reconstruct the scene as an image from the input using the model, wherein, the imaging device includes an antenna array; a transceiver unit communicably coupled to the antenna array; and a control unit communicably coupled to the antenna array and the transceiver unit, wherein, the antenna array includes a plurality of antennas configured to transmit and receive a plurality of signals to and from, respectively, the plurality of targets across the obstruction; and a plurality of interference restricting elements interposed between the plurality of antennas, wherein the plurality of interference restricting elements are configured to reduce interference of the plurality of signals among the plurality of antennas based upon microwave absorption.

[00021] In an embodiment, the imaging system classifies the targets as living or non living.

[00022] Various objects, features, aspects and advantages of the present disclosure will become more apparent from the following detailed description of preferred embodiments, along with the accompanying drawing figures in which like numerals represent like features.

[00023] Within the scope of this application it is expressly envisaged that the various aspects, embodiments, examples and alternatives set out in the preceding paragraphs, in the claims and/or in the following description and drawings, and in particular the individual features thereof, may be taken independently or in any combination. Features described in connection with one embodiment are applicable to all embodiments, unless such features are incompatible.

BRIEF DESCRIPTION OF DRAWINGS

[00024] The accompanying drawings are included to provide a further understanding of the present disclosure, and are incorporated in and constitute a part of this specification. The drawings illustrate exemplary embodiments of the present disclosure and, together with the description, serve to explain the principles of the present disclosure. The diagrams are for illustration only, which thus is not a limitation of the present disclosure.

[00025] FIG. 1 illustrates an environment having an antenna array included with an imaging device to illustrate its overall working in accordance with an embodiment of the present disclosure.

[00026] FIG. 2 illustrates a schematic system diagram associated with a through wall imaging system of Fig. 1 to illustrate its overall working in accordance with an embodiment of the present disclosure.

[00027] FIG. 3 illustrates a cross-sectional view of an antenna associated with the antenna array of Fig. 1, in accordance with an embodiment of the present disclosure. [00028] FIG. 4 illustrates a through wall imaging method for reconstructing a scene based upon identification of a plurality of targets behind an obstruction in accordance with an embodiment of the present disclosure.

DETAILED DESCRIPTION

[00029] The following is a detailed description of embodiments of the disclosure depicted in the accompanying drawings. The embodiments are in such detail as to clearly communicate the disclosure. However, the amount of detail offered is not intended to limit the anticipated variations of embodiments; on the contrary, the intention is to cover all modifications, equivalents, and alternatives falling within the spirit and scope of the present disclosure as defined by the appended claims.

[00030] In the following description, numerous specific details are set forth in order to provide a thorough understanding of embodiments of the present invention. It will be apparent to one skilled in the art that embodiments of the present invention may be practiced without some of these specific details.

[00031] Embodiments of the present invention include various steps, which will be described below. The steps may be performed by hardware components or may be embodied in machine-executable instructions, which may be used to cause a general-purpose or special- purpose processor programmed with the instructions to perform the steps. Alternatively, steps may be performed by a combination of hardware, software, and firmware and/or by human operators.

[00032] Various methods described herein may be practiced by combining one or more machine-readable storage media containing the code according to the present invention with appropriate standard computer hardware to execute the code contained therein. An apparatus for practicing various embodiments of the present invention may involve one or more computers (or one or more processors within a single computer) and storage systems containing or having network access to computer program(s) coded in accordance with various methods described herein, and the method steps of the invention could be accomplished by modules, routines, subroutines, or subparts of a computer program product. [00033] If the specification states a component or feature“may”, “can”, “could”, or “might” be included or have a characteristic, that particular component or feature is not required to be included or have the characteristic.

[00034] As used in the description herein and throughout the claims that follow, the meaning of “a,”“an,” and“the” includes plural reference unless the context clearly dictates otherwise. Also, as used in the description herein, the meaning of“in” includes“in” and“on” unless the context clearly dictates otherwise.

[00035] Exemplary embodiments will now be described more fully hereinafter with reference to the accompanying drawings, in which exemplary embodiments are shown. These exemplary embodiments are provided only for illustrative purposes and so that this disclosure will be thorough and complete and will fully convey the scope of the invention to those of ordinary skill in the art. The invention disclosed may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein. Various modifications will be readily apparent to persons skilled in the art. The general principles defined herein may be applied to other embodiments and applications without departing from the spirit and scope of the invention. Moreover, all statements herein reciting embodiments of the invention, as well as specific examples thereof, are intended to encompass both structural and functional equivalents thereof. Additionally, it is intended that such equivalents include both currently known equivalents as well as equivalents developed in the future (i.e., any elements developed that perform the same function, regardless of structure). Also, the terminology and phraseology used is for the purpose of describing exemplary embodiments and should not be considered limiting. Thus, the present invention is to be accorded the widest scope encompassing numerous alternatives, modifications and equivalents consistent with the principles and features disclosed. For purpose of clarity, details relating to technical material that is known in the technical fields related to the invention have not been described in detail so as not to unnecessarily obscure the present invention.

[00036] Thus, for example, it will be appreciated by those of ordinary skill in the art that the diagrams, schematics, illustrations, and the like represent conceptual views or processes illustrating systems and methods embodying this invention. The functions of the various elements shown in the figures may be provided through the use of dedicated hardware as well as hardware capable of executing associated software. Similarly, any switches shown in the figures are conceptual only. Their function may be carried out through the operation of program logic, through dedicated logic, through the interaction of program control and dedicated logic, or even manually, the particular technique being selectable by the entity implementing this invention. Those of ordinary skill in the art further understand that the exemplary hardware, software, processes, methods, and/or operating systems described herein are for illustrative purposes and, thus, are not intended to be limited to any particular named element.

[00037] Embodiments of the present invention may be provided as a computer program product, which may include a machine -readable storage medium tangibly embodying thereon instructions, which may be used to program a computer (or other electronic devices) to perform a process. The term“machine-readable storage medium” or“computer-readable storage medium” includes, but is not limited to, fixed (hard) drives, magnetic tape, floppy diskettes, optical disks, compact disc read-only memories (CD-ROMs), and magneto-optical disks, semiconductor memories, such as ROMs, PROMs, random access memories (RAMs), programmable read-only memories (PROMs), erasable PROMs (EPROMs), electrically erasable PROMs (EEPROMs), flash memory, magnetic or optical cards, or other type of media/machine -readable medium suitable for storing electronic instructions (e.g., computer programming code, such as software or firmware).A machine -readable medium may include a non-transitory medium in which data may be stored and that does not include carrier waves and/or transitory electronic signals propagating wirelessly or over wired connections. Examples of a non-transitory medium may include, but are not limited to, a magnetic disk or tape, optical storage media such as compact disk (CD) or digital versatile disk (DVD), flash memory, memory or memory devices. A computer -program product may include code and/or machine-executable instructions that may represent a procedure, a function, a subprogram, a program, a routine, a subroutine, a module, a software package, a class, or any combination of instructions, data structures, or program statements. A code segment may be coupled to another code segment or a hardware circuit by passing and/or receiving information, data, arguments, parameters, or memory contents. Information, arguments, parameters, data, etc. may be passed, forwarded, or transmitted via any suitable means including memory sharing, message passing, token passing, network transmission, etc.

[00038] Furthermore, embodiments may be implemented by hardware, software, firmware, middleware, microcode, hardware description languages, or any combination thereof. When implemented in software, firmware, middleware or microcode, the program code or code segments to perform the necessary tasks (e.g., a computer-program product) may be stored in a machine-readable medium. A processor(s) may perform the necessary tasks.

[00039] Systems depicted in some of the figures may be provided in various configurations. In some embodiments, the systems may be configured as a distributed system where one or more components of the system are distributed across one or more networks in a cloud computing system.

[00040] Each of the appended claims defines a separate invention, which for infringement purposes is recognized as including equivalents to the various elements or limitations specified in the claims. Depending on the context, all references below to the "invention" may in some cases refer to certain specific embodiments only. In other cases it will be recognized that references to the "invention" will refer to subject matter recited in one or more, but not necessarily all, of the claims.

[00041] All methods described herein may be performed in any suitable order unless otherwise indicated herein or otherwise clearly contradicted by context. The use of any and all examples, or exemplary language (e.g.,“such as”) provided with respect to certain embodiments herein is intended merely to better illuminate the invention and does not pose a limitation on the scope of the invention otherwise claimed. No language in the specification should be construed as indicating any non-claimed element essential to the practice of the invention.

[00042] Various terms as used herein are shown below. To the extent a term used in a claim is not defined below, it should be given the broadest definition persons in the pertinent art have given that term as reflected in printed publications and issued patents at the time of filing.

[00043] The present disclosure relates to through-the-wall imaging. More particularly, the present disclosure relates to an antenna array, an imaging device, and a system for through wall imaging with interference removal along with good pixel intensity and reduced scanning time. In an example, scanning time is 5-10 seconds for a 1 m length of the obstruction. The obstruction may be a wall.

[00044] According to an aspect of the present disclosure, an antenna array for through wall imaging includes a plurality of antennas configured to transmit and receive a plurality of signals to and from, respectively, a plurality of targets across an obstruction; and a plurality of interference restricting elements interposed between the plurality of antennas, wherein the plurality of interference restricting elements are configured to reduce interference of the plurality of signals among the plurality of antennas based upon microwave absorption.

[00045] In an embodiment, the plurality of interference restricting elements is an absorber coated aluminum sheet.

[00046] According to another aspect of the present disclosure, a portable imaging device for through wall imaging includes an antenna array; a transceiver unit communicably coupled to the antenna array; and a control unit communicably coupled to the antenna array and the transceiver unit, wherein, the antenna array includes a plurality of antennas configured to transmit and receive a plurality of signals to and from, respectively, a plurality of targets across an obstruction; and a plurality of interference restricting elements interposed between the plurality of antennas, wherein the plurality of interference restricting elements are configured to reduce interference of the plurality of signals among the plurality of antennas based upon microwave absorption.

[00047] In an embodiment, the control unit is configured to control transmitting, receiving, and real time processing of the plurality of signals of the antenna array.

[00048] In an embodiment, the transceiver unit operates in a frequency range of 1.5GHz- 3.5GHz.

[00049] According to another aspect of the present disclosure, a through wall imaging system configured for a delay based scanning for reconstructing a scene based upon identification of a plurality targets behind an obstruction includes a hardware processor; and a machine-readable storage medium storing instructions that, when executed by the hardware processor, cause the hardware processor to receive an input from an imaging device; estimate parameters of the obstruction based on processing of the input; generate a model of permittivity of the obstruction using the parameters; classify the targets based upon the model; and reconstruct the scene as an image from the input using the model, wherein, the imaging device includes an antenna array; a transceiver unit communicably coupled to the antenna array; and a control unit communicably coupled to the antenna array and the transceiver unit, wherein, the antenna array includes a plurality of antennas configured to transmit and receive a plurality of signals to and from, respectively, the plurality of targets across the obstruction; and a plurality of interference restricting elements interposed between the plurality of antennas, wherein the plurality of interference restricting elements are configured to reduce interference of the plurality of signals among the plurality of antennas based upon microwave absorption.

[00050] In an embodiment, the imaging system classifies the targets as living or non living.

[00051] FIG. 1 illustrates an environment having an antenna array (100) included with an imaging device (106) to illustrate its overall working in accordance with an embodiment of the present disclosure. In an embodiment, the imaging device (106), and in turn the antenna array (100), is operatively and communicably coupled to a through wall imaging system (112) for reconstructing a scene based upon identification of a plurality targets (90) behind an obstruction (95) in accordance with an embodiment of the present disclosure. In an example, the obstruction (95) may be a wall or the like opaque or semi transparent structure. Further in an example, the plurality targets (90) may be a living thing like humans, or non living things like boxes, machines, etc. In an example, the imaging device (106) may be a portable or handheld device.

[00052] In an embodiment, as shown in FIG. 1, the antenna array (100) includes a plurality of antennas (102) configured to transmit and receive a plurality of signals to and from, respectively, a plurality of targets (90) across an obstruction (95). In an embodiment, the antenna array (100) further includes a plurality of interference restricting elements (104) interposed between the plurality of antennas (102), wherein the plurality of interference restricting elements (104) are configured to reduce interference of the plurality of signals among the plurality of antennas (102) based upon microwave absorption. In an example, the antenna array (100) may be a substrate over which the plurality of antennas (102) may be disposed, and the plurality of antennas (102) defines spaces among each other, the spaces being configured for receiving the plurality of interference restricting elements (104). In an example, the role of interference restricting elements (104) is isolation among the antennas (102) to remove the interference and thereby improving the pixel intensity. In an example, the interference restricting elements (104) reduce the interference between the antennas (102) below -40.0dB.

[00053] Alternatively, the plurality of interference restricting elements (104) may be configured to absorb any wave or signal necessary to reduce interference of the plurality of signals among the plurality of antennas (102). In an example, the plurality of interference restricting elements (104) is an absorber coated aluminium / aluminum sheet of 2.0 mm thickness. In an example, the antenna array (100) may be a compact sized, wideband (Freq 0.8 GHz-4.0 GHz) with high gain antenna designed in CST software. In an example, the antenna array (100) may include two interference restricting elements (104) placed across a transmitting antenna (102), and two receiving antennas (102) are placed in the left and the right of the transmitting antenna (102) at a separation of 5.0 cm.

[00054] Further in an embodiment, FIG. 1 illustrates the imaging device (106) for through wall imaging. The imaging device (106) includes the antenna array (100), a transceiver unit (108) communicably coupled to the antenna array (100), and a control unit (110) communicably coupled to the antenna array (100) and the transceiver unit (108). In an example, the control unit (110) may be any known micro processing circuitry configured to control transmitting, receiving, and real time processing of the plurality of signals of the antenna array (100). The control unit (110) may include High speed cables (around 3 psec), High power handling capacity (+27 dBm), Very High linearity (IP3 54 dBm), programmable Switching sequence, Low insertion loss (1.6 dB typical) and high isolation (50 dB typical), etc.

[00055] Further in an embodiment, the transceiver unit (108) transmits one or more pulses using some or all of the plurality of antennas (102) of the antenna array (100). The transmitted pulse propagates through the obstruction (95), and is reflected by the possible targets (90) in a scene behind the obstruction (95). Reflected signals (impulse responses), corresponding to each pulse, are received by the plurality of antennas (102) of the antenna array (100). The received signals include primary reflections received via direct paths, and indirect secondary reflections received by multi-paths. It is noted, that in some embodiments, an antenna (102) can be used to only transmit or only receive pulses or both transmit and receive pulses.

[00056] Further in an embodiment, the received signals are processed by through wall imaging system (112) to produce an image that reconstructs the scene including the targets (90). In an example, the scene behind the obstruction (95) is reconstructed as the image by transmitting the plurality of signals through the obstruction (95) into the scene, and estimating parameters of, for example dielectric permittivity and permeability, the obstruction (95) from the reflected signals. A model of the obstruction (95) is generated using the parameters. Then, the scene is reconstructed from the reflected signals using the model.

[00057] In an example, the transceiver unit (108) is operated in the frequency range of 1.5GHz-3.5GHz and the number of sweep points can be selected as per the user requirement. The parameters involved are listed in table below.

[00058] FIG. 2 illustrates a schematic system diagram associated with the through wall imaging system (112) of Fig. 1 to illustrate its overall working in accordance with an embodiment of the present disclosure. In an example, the system (112) is based on Stepped Frequency Continuous Wave (SFCW) radar concept and working from 1.5-3.5 GHz, which can provide good range resolution and cross range resolution, that can be used for imaging the targets (90) behind the obstruction (95). Further, the system (112) is configured for delay based scanning using the antenna array (100) which can reduce the scanning time and cost.

[00059] In an aspect, the system (112) may comprise one or more hardware processor(s) (202). The one or more hardware processor(s) (202) may be implemented as one or more microprocessors, microcomputers, microcontrollers, digital signal processors, central processing units, logic circuitries, and/or any devices that manipulate data based on operational instructions. Among other capabilities, the one or more hardware processor(s) (202) are configured to fetch and execute computer-readable instructions stored in a memory (204) of the system (112). The memory (204) may store one or more computer-readable instructions or routines, which may be fetched and executed to create or share the data units over a network service. The memory (204) may comprise any non-transitory storage device including, for example, volatile memory such as RAM, or non-volatile memory such as EPROM, flash memory, and the like.

[00060] The system (112) also includes an interface(s) (206). The interface(s) (206) may comprise a variety of interfaces, for example, interfaces for data input and output devices, referred to as I/O devices, storage devices, and the like. The interface(s) (206) may facilitate communication of system (112) with various devices coupled to the system (112) such as the imaging device (106). The interface(s) (206) may also provide a communication pathway for one or more components of system (112). Examples of such components include, but are not limited to, processing engine(s) (208) and data (210).

[00061] The processing engine(s) (208) may be implemented as a combination of hardware and programming (for example, programmable instructions) to implement one or more functionalities of the processing engine(s) (208). In examples described herein, such combinations of hardware and programming may be implemented in several different ways. For example, the programming for the processing engine(s) (208) may be processor executable instructions stored on a non-transitory machine-readable storage medium and the hardware for the processing engine(s) (208) may comprise a processing resource (for example, one or more processors), to execute such instructions. In the present examples, the machine -readable storage medium may store instructions that, when executed by the processing resource, implement the processing engine(s) (208). In such examples, the system (112) may comprise the machine- readable storage medium storing the instructions and the processing resource to execute the instructions, or the machine -readable storage medium may be separate but accessible to system (112) and the processing resource. In other examples, the processing engine(s) (208) may be implemented by electronic circuitry.

[00062] The data (210) may comprise data that is either stored or generated as a result of functionalities implemented by any of the components of the processing engine(s) (208).

[00063] In an exemplary embodiment, the processing engine(s) (208) may comprise an input module (212), an estimation module (214), a model generation module (216), a classification module (218), and an image reconstruction module (220).

[00064] It would be appreciated that modules being described are only exemplary modules and any other module or sub-module may be included as part of the system (112). These modules too may be merged or divided into super-modules or sub-modules as may be configured.

[00065] Functionalities of various modules as mentioned above will now be described in detail in the foregoing description in accordance with an embodiment of the present disclosure. In an embodiment, the various modules mentioned above enables the system (112) for conducting and managing an assessment in accordance with an embodiment of the present disclosure. [00066] In an embodiment, input module (212) is configured to receive an input from the imaging device (106). In an example, the input is the received signals gathered by the imaging device (106). Further, the estimation module (214) is configured to estimate parameters of the obstruction (95) based on processing of the input received signals. Further, the model generation module (216) is configured to generate a model of permittivity of the obstruction (95) using the parameters of the obstruction (95). Further, the classification module (218) classify the targets (90) based upon the model generated. In an example, the targets (90) are classified as living or non-living targets (90). Further, the image reconstruction module (220) reconstructs the scene as an image from the input using the model generated, and the targets (90) classified.

[00067] In an example, the developed through wall imaging system (112) may be coupled with five indigenously developed antenna array (100), which are used for transmitting and receiving the signal. The antenna array (100) is connected to the transceiver unit (108) through the control unit (110). A good isolation among the antennas (102) in the antenna array (100) is obtained by placing the interference restricting elements (104) in between the antenna array (100). The system (112) may be a computing device (e.g. laptop), where further signal collection and processing is carried out. In an example, the imaging device (106) may be enclosed inside a designed acrylic box, and the box may be communicably and operatively coupled with the system (112).

[00068] The antenna array (100) will collect the signals and it will be processed in the system (112) in real time. Several signal processing steps; i.e. range profile generation, delay and sum algorithm, clutter removal and thresholding techniques may be implemented in real time, and finally A-, B- and C-scan may be generated to view the output, i.e., the reconstructed scene.

[00069] FIG. 3 illustrates a cross-sectional view of an antenna (102) associated with the antenna array (100) of Fig. 1, in accordance with an embodiment of the present disclosure. As shown, the antenna (102) defines W _E : Input slot width, W _A : Slot width at radiating area, and Wo: Output slot width, wherein Propagating area is defined by WE < W < WA, and Radiating region is defined by W _A < W < Wo-

[00070] FIG. 4 illustrates a through wall imaging method (400) for reconstructing a scene based upon identification of a plurality of targets (90) behind an obstruction (95) in accordance with an embodiment of the present disclosure. [00071] In an aspect, the proposed method may be described in general context of computer executable instructions. Generally, computer executable instructions can include routines, programs, objects, components, data structures, procedures, modules, functions, etc., that perform particular functions or implement particular abstract data types. The method can also be practiced in a distributed computing environment where functions are performed by remote processing devices that are linked through a communications network. In a distributed computing environment, computer executable instructions may be located in both local and remote computer storage media, including memory storage devices.

[00072] The order in which the method as described is not intended to be construed as a limitation, and any number of the described method blocks may be combined in any order to implement the method or alternate methods. Additionally, individual blocks may be deleted from the method without departing from the spirit and scope of the subject matter described herein. Furthermore, the method may be implemented in any suitable hardware, software, firmware, or combination thereof. However, for ease of explanation, in the embodiments described below, the method may be considered to be implemented in the above described system.

[00073] In an embodiment, at step (402) the method (400) includes receiving an input from the imaging device (106). In an example, the input is the received signals gathered by the imaging device (106). At step (404) the method (400) includes estimating parameters of the obstruction (95) based on processing of the input received signals. Further, at step (406) the method (400) includes generating a model of permittivity of the obstruction (95) using the parameters of the obstruction (95). Further, at step (408) the method (400) includes classifying the targets (90) based upon the model generated. In an example, the targets (90) are classified as living or non-living targets (90). Further, at step (410) the method (400) includes reconstructing the scene as an image from the input using the model generated, and the targets (90) classified.

[00074] While some embodiments of the present disclosure have been illustrated and described, those are completely exemplary in nature. The disclosure is not limited to the embodiments as elaborated herein only and it would be apparent to those skilled in the art that numerous modifications besides those already described are possible without departing from the inventive concepts herein. All such modifications, changes, variations, substitutions, and equivalents are completely within the scope of the present disclosure. The inventive subject matter, therefore, is not to be restricted except in the spirit of the appended claims. ADVANTAGES OF THE PRESENT DISCLOSURE

[00075] The present disclosure overcome problems associated with the conventional prior art.

[00076] The present disclosure provides a prototype of through wall imaging that has the capability to detect and identify the targets behind the wall.

[00077] The present disclosure provides a system that automatically generates B-scan and C-scan for detection and identification of the targets.

[00078] The present disclosure provides reduced scanning time, interference removal among the antenna, good pixel intensity, and a cost effective portable solution.

[00079] The present disclosure provides antenna array which is compact and is of light weight (~3 kg).

[00080] The present disclosure provides portable and cost effective solution to the problems of the prior art.

[00081] The present disclosure provides good range resolution and cross range resolution, that can be used for imaging a target behind the wall.

[00082] The present disclosure provides a solution wherein scanning time to image the target is reduced by introducing the concept of array antenna. In an example, scanning time associated with the system is 5-10 seconds for a 1 m length of the obstruction.

[00083] The present disclosure provides a solution wherein crosstalk in the antenna array is minimized by the coating of developed microwave absorber, which improved the image quality.