DESC:
FIELD OF THE INVENTION
The present disclosure relates generally to the field of radar signal processing and more particularly to a method and a radar transceiver for plotting three-dimensional (3D) images of one or more targets.

BACKGROUND
Radar transceivers are instrumental in various applications, including navigation, surveillance, and object detection. Traditional radar transceivers emit radio waves and analyze the reflected signals to determine the location and velocity of objects within their range. However, conventional methodologies primarily focus on two-dimensional (2D) detection and imaging, which can limit the comprehensiveness and accuracy of the object representation. The primary function of a radar transceiver is to detect the presence, location, and velocity of objects (targets) by emitting radio waves and analyzing echoes returned from those objects. Traditional radar transceivers, while effective for range and velocity estimation, predominantly provide 2D representations that lack depth information, resulting in significant limitations in terms of spatial understanding and target identification.
Recent advances in radar technology have introduced techniques for enhancing target detection and characterization, including the use of multiple-input multiple-output (MIMO) systems, synthetic aperture radar (SAR), and phased array radar transceivers. These technologies offer improvements in resolution and target discrimination but still often fall short in delivering comprehensive 3D representations of the radar scene, especially in real-time or near-real-time scenarios.
Creating accurate 3D images of targets from radar signals is a complex challenge that involves sophisticated signal processing and data interpretation methods. The process must effectively address issues such as signal attenuation, noise, interference, and the multi-path distortion of signals. Moreover, the computational demand for processing and reconstructing 3D images from the high-dimensional data collected by advanced radar transceivers is substantial, necessitating efficient systems that can operate within the constraints of available hardware and software environments.
Furthermore, existing techniques for 3D radar imaging, such as Inverse Synthetic Aperture Radar (ISAR) and tomographic processing, often require specific operational conditions, such as controlled target movements or multiple passes over the target, which may not be feasible in all application scenarios. Existing methodologies, despite their prevalence in literature and practical application, demand hardware specifications unattainable by most contemporary radar transceivers, including, but not limited to, the phase-time linearity of the synthesizer or signal generator, and a uniform beam shape of antennae.
Figure 1 illustrates an example scenario where multiple points on a single target are misidentified as separate targets by the existing method, in accordance with prior art.
As shown in Figure 1, a radio transceiver (R) 104 has identified multiple points (P1, P2) of a target (T) 102 as two different targets. For instance, during a routine patrol, the radar transceiver (R) 104 detects a large object as the target (T). In the present scenario, a human is considered as the target. However, due to the object’s complex structure and irregular surface, the radar transceiver (R) 104 signals get reflected back from different parts of the object, each at varying angles. The radar transceiver (R) 104 misinterprets these multiple reflections from multiple points (P1, P2) as separate, distinct targets. As a result, the radar transceiver (R) 104 begins tracking several objects, each with a different position, speed, and trajectory. The radar transceiver (R) 104 falsely identifies multiple targets scattered across the targeted area, which generally creates confusion during navigation. Such a misidentification could potentially lead to incorrect threat assessments or unnecessary actions if the radar transceiver (R) 104 is not calibrated to recognize these multiple signals come from the same object. As a result, the radar transceiver (R) 104 may generate incorrect cues to plot the image of such an object.
Figure 2 depicts an example scenario in which a single target is mistakenly identified as multiple separate targets by a set of radar transceivers positioned at equal distances from a reference radar transceiver, in accordance with the prior art.
As shown in Figure 2, for instance, in a coastal surveillance system designed to track maritime traffic, several radar transceivers (R1-Rn) are strategically positioned at equidistant locations along the shoreline. In the present scenario, three radar transceivers (R1-R3) are depicted for ease of understanding. The radar transceiver R2 is considered a reference radar transceiver, and radar transceivers R1 and R3 are equidistant from the reference radar transceiver R2. At a certain point, the distance of the target from the radar transceiver R1 and radar transceiver R2 will be equal to D1, while the distance of the target from the radar transceiver R2 will be D2. These radar transceivers (R1-R3) are meant to work together to create a comprehensive detection grid, with each radar transceiver (R1-R3) covering a portion of the sea. When a vessel sails through the targeted area, and due to the vessel’s size and shape, radar reflections may bounce off from various parts of the vessel, including its hull, mast, and containers. As the ship moves across the coverage area, each of the radar transceivers (R1-R3) detects different signals from different points on the vessel. These radar transceivers (R1-R3) may be unable to correlate these multiple signals as originating from a single target and misidentify the vessel as several separate objects as each radar transceiver (R1-R3) identifies the vessel as the different target. As a result, the radar transceivers (R1-R3) erroneously report by plotting images of multiple vessels at the same location, each with a slightly different speed and heading, causing confusion and potentially leading to unnecessary alerts or evasive actions by nearby vessels. The misidentification eventually occurs due to the overlapping of data from multiple points of the vessel.
Accordingly, there is a need for a technical solution that may solve the above-defined problems and provide a radar transceiver and a method capable of generating real-time 3D images of the target space, thereby optimizing resource efficiency and overcoming the limitations imposed by conventional hardware requirements. Also, there is a growing need for advanced radar technologies capable of generating 3D images of targets to provide enhanced spatial resolution and object identification.

SUMMARY
This summary is provided to introduce a selection of concepts, in a simplified format, that are further described in the detailed description of the disclosure. This summary is neither intended to identify key or essential inventive concepts of the disclosure nor is it intended to determine the scope of the disclosure.
In an aspect of the present disclosure, a method for plotting three-dimensional (3D) images of one or more targets is provided. The method includes receiving, through a plurality of channels, echoes from the one or more targets at a plurality of radar transceivers. The method further includes measuring, at each radar transceiver of the plurality of radar transceivers, a range-profile (RP) associated with the received echoes from the one or more targets. The method further includes correlating a radar range resolution (Rr) and range-profiles (RP) of the corresponding echoes from the one or more targets. The method further includes determining whether the measured range-profiles (RP) corresponding to at least two echoes belong to either same target or different targets amongst the one or more targets based on the correlation. For at least two echoes that belong to the same target, range-profiles (RP) corresponding to one or more grid locations are estimated based at least on an average of range-profiles (RP) and determining a minimum error margin based on a comparison of the measured range-profile (RP) with the estimated range-profiles (RP). For at least two echoes that belong to the same target, the one or more grid locations associated with the one or more targets are determined. The determination of the one or more grid locations is based on the determined minimum error margins associated with the same target, and the measured range-profiles (RP) corresponding to at least two echoes that belong to the different targets. The method further includes plotting the 3D images representing at least a corresponding range, a corresponding elevation, and a corresponding azimuth of the one or more targets based on the determined one or more grid locations associated with the one or more targets.
In another aspect of the present disclosure, a radar transceiver for plotting three-dimensional (3D) images of one or more targets is provided. The radar transceiver includes a plurality of channels configured to receive echoes from the one or more targets. The radar transceiver includes at least one processor in communication with a memory. The processor is configured to measure a range-profile (RP) associated with the received echoes from the one or more targets. The processor is configured to correlate a radar range resolution (Rr) and range-profiles (RP) of the corresponding echoes from the one or more targets. The processor is further configured to determine whether the measured range-profiles (RP) corresponding to at least two echoes belong to either a same target or different targets amongst the one or more targets based on the correlation. For at least two echoes that belong to the same target, the processor is configured to estimate range-profiles (RP) corresponding to one or more grid locations based at least on an average of range-profiles (RP). For at least two echoes that belong to the same target, the processor is configured to further determine a minimum error margin based on a comparison of the measured range-profile (RP) with the estimated range-profiles (RP). The processor is configured to further determine the one or more grid locations associated with the one or more targets. The one or more grid locations are determined based at least on one of the determined minimum error margins associated with the same target, and the measured range-profiles (RP) corresponding to at least two echoes that belong to the different targets. The processor is configured to further plot the 3D images representing at least a corresponding range, a corresponding elevation, and a corresponding azimuth of the one or more targets based on the determined one or more grid locations associated with the one or more targets.
To further clarify the advantages and features of the present invention, a more particular description of the invention will be rendered by reference to specific embodiments thereof, which are illustrated in the appended drawings. It is appreciated that these drawings depict only typical embodiments of the invention and are therefore not to be considered limiting of its scope. The invention will be described and explained with additional specificity and detail in the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

These and other features, aspects, and advantages of the present invention will become better understood when the following detailed description is read with reference to the accompanying drawings in which like characters represent like parts throughout the drawings, wherein:
Figure 1 illustrates an example scenario where multiple points on a single target are misidentified as separate targets by the existing method, in accordance with prior art.
Figure 2 depicts an example scenario in which a single target is mistakenly identified as multiple separate targets by a set of radar transceivers positioned at equal distances from a reference radar transceiver, in accordance with the prior art.
Figure 3 illustrates an environment for implementing radar transceivers for plotting three-dimensional (3D) images of one or more targets, according to an embodiment of the present disclosure;
Figure 4 illustrates the block diagram for the radar transceiver as illustrated in Figure 3, according to an embodiment of the present disclosure;
Figure 5 illustrates a method for plotting the 3D images of one or more targets, according to an embodiment of the present disclosure;
Figure 6a illustrates an exemplary flow chart indicating the calculations done in each of the plurality of channels with respect to each possible pair of detected targets, according to an exemplary implementation of the present disclosure;
Figure 6b illustrates a flow chart, in furtherance to Figure 6a, indicating the calculations done by considering all relevant locations grids within the radar detection space, according to an exemplary implementation of the present disclosure; and
Figure 6c illustrates a flow chart, in furtherance to Figure 6b, for determining the most probable range-profile ([X, Y, Z] or [Range, Azimuth, Elevation] coordinates) for any given target index, according to an exemplary implementation of the present disclosure.
Further, skilled artisans will appreciate that those elements in the drawings are illustrated for simplicity and may not have necessarily been drawn to scale. For example, the flow charts illustrate the method in terms of the most prominent steps involved to help improve understanding of aspects of the present invention. Furthermore, in terms of the construction of the device, one or more components of the device may have been represented in the drawings by conventional symbols, and the drawings may show only those specific details that are pertinent to understanding the embodiments of the present invention so as not to obscure the drawings with details that will be readily apparent to those of ordinary skill in the art having the benefit of the description herein.

DETAILED DESCRIPTION

For the purpose of promoting an understanding of the principles of the present disclosure, reference will now be made to the various embodiments and specific language will be used to describe the same. It will nevertheless be understood that no limitation of the scope of the present disclosure is thereby intended, such alterations and further modifications in the illustrated system, and such further applications of the principles of the present disclosure as illustrated therein being contemplated as would normally occur to one skilled in the art to which the present disclosure relates.
It will be understood by those skilled in the art that the foregoing general description and the following detailed description are explanatory of the present disclosure and are not intended to be restrictive thereof.
Whether or not a certain feature or element was limited to being used only once, it may still be referred to as “one or more features” or “one or more elements” or “at least one feature” or “at least one element.” Furthermore, the use of the terms “one or more” or “at least one” feature or element does not preclude there being none of that feature or element, unless otherwise specified by limiting language including, but not limited to, “there needs to be one or more…” or “one or more elements is required.”
Reference is made herein to some “embodiments.” It should be understood that an embodiment is an example of a possible implementation of any features and/or elements of the present disclosure. Some embodiments have been described for the purpose of explaining one or more of the potential ways in which the specific features and/or elements of the proposed disclosure fulfill the requirements of uniqueness, utility, and non-obviousness.
Use of the phrases and/or terms including, but not limited to, “a first embodiment,” “a further embodiment,” “an alternate embodiment,” “one embodiment,” “an embodiment,” “multiple embodiments,” “some embodiments,” “other embodiments,” “further embodiment”, “furthermore embodiment”, “additional embodiment” or other variants thereof do not necessarily refer to the same embodiments. Unless otherwise specified, one or more particular features and/or elements described in connection with one or more embodiments may be found in one embodiment or may be found in more than one embodiment, or may be found in all embodiments, or may be found in no embodiments. Although one or more features and/or elements may be described herein in the context of only a single embodiment, or in the context of more than one embodiment, or in the context of all embodiments, the features and/or elements may instead be provided separately or in any appropriate combination or not at all. Conversely, any features and/or elements described in the context of separate embodiments may alternatively be realized as existing together in the context of a single embodiment.
Any particular and all details set forth herein are used in the context of some embodiments and therefore should not necessarily be taken as limiting factors to the proposed disclosure.
The terms “comprises”, “comprising”, or any other variations thereof, are intended to cover a non-exclusive inclusion, such that a process or method that comprises a list of steps does not include only those steps but may include other steps not expressly listed or inherent to such process or method. Similarly, one or more devices or sub-systems or elements or structures or components proceeded by “comprises... a” does not, without more constraints, preclude the existence of other devices or other sub-systems or other elements or other structures or other components or additional devices or additional sub-systems or additional elements or additional structures or additional components.
The term “couple” and the derivatives thereof refer to any direct or indirect communication between two or more elements, whether or not those elements are in physical contact with each other. The terms “transmit”, “receive”, and “communicate” as well as the derivatives thereof encompass both direct and indirect communication. The term “or” is an inclusive term meaning “and/or”. The phrase “associated with,” as well as derivatives thereof, refer to include, be included within, interconnect with, contain, be contained within, connect to or with, coupled to or with, be communicable with, cooperate with, interleave, juxtapose, be proximate to, be bound to or with, have, have a property of, have a relationship to or with, or the like. The term “controller” refers to any device, system, or part thereof that controls at least one operation. The functionality associated with any particular controller may be centralized or distributed, whether locally or remotely. The phrase “at least one of,” when used with a list of items, means that different combinations of one or more of the listed items may be used, and only one item in the list may be needed. For example, “at least one of A, B, and C” includes any of the following combinations: A, B, C, A and B, A and C, B and C, and A and B and C, and any variations thereof. As an additional example, the expression “at least one of a, b, or c” may indicate only a, only b, only c, both a and b, both a and c, both b and c, all of a, b, and c, or variations thereof. Similarly, the term “set” means one or more. Accordingly, the set of items may be a single item or a collection of two or more items.
Moreover, multiple functions described below may be implemented or supported by one or more computer programs, each of which is formed from computer-readable program code and embodied in a computer-readable medium. The terms “application” and “program” refer to one or more computer programs, software components, sets of instructions, procedures, functions, objects, classes, instances, related data, or a portion thereof adapted for implementation in a suitable computer-readable program code. The phrase “computer readable program code” includes any type of computer code, including source code, object code, and executable code. The phrase “computer-readable medium” includes any type of medium capable of being accessed by a computer, such as Read Only Memory (ROM), Random Access Memory (RAM), or any other type of memory. A “non-transitory” computer-readable medium excludes wired, wireless, optical, or other communication links that transport transitory electrical or other signals. A non-transitory computer-readable medium includes media where data may be permanently stored and media where data may be stored and later overwritten, such as a rewritable optical disc or an erasable memory device.
The various embodiments of the present disclosure describe a novel radar transceiver and method for processing data from the plurality channels of one or more radar transceivers to create accurate three-dimensional (3D) images of detected targets.
In the following description, for the purpose of explanation, specific details are set forth in order to provide an understanding of the present disclosure. It will be apparent, however, to one skilled in the art that the present disclosure may be practiced without these details. One skilled in the art will recognize that embodiments of the present disclosure, some of which are described below, may be incorporated into a number of systems.
However, the radar transceivers and methods are not limited to the specific embodiments described herein. Further, the structures and devices shown in the figures are illustrative of exemplary embodiments of the present disclosure and are meant to avoid obscuring the present disclosure.
It should be noted that the description merely illustrates the principles of the present disclosure. It will thus be appreciated that those skilled in the art will be able to devise various arrangements that, although not explicitly described herein, embody the principles of the present disclosure. Furthermore, all examples recited herein are principally intended expressly to be only for explanatory purposes to help the reader understand the principles of the disclosure and the concepts contributed by the inventor to further the art and are to be construed as being without limitation to such specifically recited examples and conditions. Moreover, all statements herein reciting principles, aspects, and embodiments of the disclosure, as well as specific examples thereof, are intended to encompass equivalents thereof.
The present disclosure is specifically directed towards radar transceivers equipped with more than two receiver channels, each channel generating a corresponding unique range-profile (RP) indicative of target range variations over time. Crucial to the accurate determination of a target’s location within the radar’s field of view (FOV) are the azimuth and elevation angles, which, when synergistically combined with the range information from each receiver channel’s range-profile (RP), facilitate the construction of a comprehensive 3D image of the target space within the radar FOV. The present disclosure introduces an innovative method for the precise calculation of the azimuth angles of targets and their subsequent integration with the corresponding range-profiles (RP), aimed at achieving the assembly of the final 3D image while optimizing both time and memory utilization.
Figure 3 illustrates an environment 100 for implementing radar transceivers 104a, 104b, and 104c for plotting the 3D images of one or more targets 102, according to an embodiment of the present disclosure.
Figure 4 illustrates the block diagram for the radar transceiver 104 as illustrated in Figure 3, according to an embodiment of the present disclosure. For the sake of clarity, Figure 3 and Figure 4 are in reference to each other.
Referring to Figure 3, the environment 300 depicts that the one or more targets 102 may be detected by the radar transceivers 104a, 104b, and 104c (which may be interchangeably referred to herein and after as “radar transceivers 104”) automatically without any human intervention which may result in optimizing the memory and the time requirements.
Referring to Figure 4, the each radar transceiver 104 may include an antenna 402, at least one processor 404, a memory 406, and a data unit 408.
In an embodiment, the each radar transceiver 104 may comprise a minimum of three channels. The radar transceivers 104 may be arranged asymmetrically across the azimuth-elevation plane to ensure comprehensive coverage. Each radar transceiver 104 may function in both transmit and receive modes for maximum efficiency and the spacing between adjacent antennas 402 must be at least equal to the radar transceiver’s 104 range resolution (Rr), ensuring clarity and precision of the 3D imaging process. In a non-limiting example, each radar transceiver 104 may be useful in any handheld radar, such as, but not limited to, Phased Array Radar Receivers, FMCW (Frequency Modulated Continuous Wave) Multi-channel Receivers, Doppler Multi-channel Radar Receivers, Synthetic Aperture Radar (SAR) Handheld Receivers, UWB (Ultra-Wideband) Multi-channel Radar Receivers, MIMO (Multiple Input Multiple Output) Radar Receivers, Multi-frequency Radar Receivers, Wideband Radar Receivers, Multi-Channel Ground Penetrating Radar (GPR) Receivers, and like.
In an embodiment, the antenna 402 may be an essential component for transmitting as well as receiving radar signals to detect the target 102. In an implementation, the antennas 402 may include patch antennas, which may be flat and small, offering good directional performance. In another implementation, the antennas 402 may include dipole antennas, which may be simple and effective for lower frequencies. The antenna 402 may transmit the radar transceiver signal 104 in the form of an electromagnetic wave, and when the electromagnetic wave hits the target 102, and may get reflected back to the antenna 402, where the received signal is processed to gather information such as distance, speed, or target presence. The antenna’s 402 frequency range, beamwidth, and directional properties may be selected to optimize the radar transceiver’s 104 detection capabilities while maintaining compactness. The design of the antenna 402 may minimize interference and power consumption to extend the battery life of the radar transceiver 104. In an advantageous aspect, the design of the antenna 402 may ensure efficient operation in various environmental conditions, making the antenna 402 suitable for applications such as speed detection, obstacle avoidance, and security monitoring.
In an embodiment, the at least one processor 404 may be a single processing unit or several units, all of which could include multiple computing units. The at least one processor 404 may be implemented as one or more microprocessors, microcomputers, microcontrollers, digital signal processors, central processing units, state machines, logic circuitries, and/or any devices that manipulate signals based on operational instructions. Among other capabilities, the at least one processor 404 may be configured to fetch and execute computer-readable instructions and data stored in the memory 406.
In an embodiment, the memory 406 may include any non-transitory computer-readable medium known in the art including, for example, volatile memory, such as static random access memory (SRAM) and dynamic random access memory (DRAM), and/or non-volatile memory, such as read-only memory (ROM), erasable programmable ROM, flash memories, hard disks, optical disks, and magnetic tapes.
In an embodiment, the data unit 408 amongst other things, includes routines, programs, objects, components, data structures, etc., which perform particular tasks or implement data types. The data unit 408 may also be implemented as signal processor(s), state machine(s), logic circuitries, and/or any other device or component that manipulates signals based on operational instructions.
Referring back to Figure 3, in an exemplary embodiment, the environment 300 may comprise several integral modules designed for efficient real-time application. The environment 300 depicts the initial reception of echoes from the one or more targets 102 at each radar transceiver 104, followed by the creation of a range-profile (RP) for each channel of a plurality of channels. In a non-limiting example, the range-profile (RP) may be referred to as a representation of how the signals from the radar transceiver 104 interact with the one or more targets 102 at various distances from the radar transceiver 104. In another non-limiting example, the range-profile (RP) may be referred to as the reflection or return of signals from the radar transceiver 104 based on the distance or range to the one or more targets 102 that the radar transceiver 104 detects. The range-profile (RP) generation may be contingent upon the capability of each radar transceiver 104 to discern multiple targets 102, provided they maintain a minimum separation equivalent to a radar range resolution (Rr), as dictated by the bandwidth of a transmitted waveform. In a non-limiting example, the radar range resolution (Rr) may be referred to as the ability of a radar transceiver 104 to distinguish at least between two targets 102 that may be at different distances or ranges from the radar transceiver 104. For instance, the radar range resolution (Rr) may be a minimum distance between the two targets 102 along the radar transceiver’s 104 line of sight which may allow the radar transceiver 104 to detect these targets as separate targets rather than a single target. The spatial arrangement of antennae 402 corresponding to the radar transceiver 104 may mandate a minimum distance of half the wavelength, corresponding to the middle frequency of the transmitted bandwidth. Such an arrangement may help in ensuring accurate 3D imaging encompassing the range and the azimuth of each target 102 relative to the radar transceiver 104, thereby facilitating a comprehensive understanding of target locations. The range resolution (Rr) may depend on the pulse duration or bandwidth of the radar transceiver 104’s signal.
Referring to Figures 3 and 4, the plurality of channels of the radar transceiver 104 may be configured to receive echoes from the one or more targets 102. The at least one processor 404 may be in communication with the memory 406. The at least one processor 404 may be configured to measure a range-profile (RP) associated with the received echoes from the one or more targets 102.
In an embodiment, for each radar transceiver 104, data may be received through the corresponding plurality of channels. The data format used may be determined by an application and software available. The number of the plurality of channels may be represented by NRx, and a plurality of grid dimensions (limited and selected based on the radar range resolution (Rr)) of the radar transceiver’s 104 FOV may be represented by [NX,NY,NZ]. The range-profile (RP) of each of the plurality of channels (which may be represented interchangeably as ?RP?_(target_index)^(receiver_index)) may include a corresponding Foast Fourier Transformation (FFT) information regarding the range of targets 102 with respect to the plurality of channels. In an advantageous aspect, the accuracy of the range-profile (RP) and the change of range-profile (RP) over the plurality of channels may help in determining the performance of the radar transceiver 104.
The at least one processor 404 may be configured to correlate the radar range resolution (Rr) and the range-profiles (RP) of the corresponding echoes from the one or more targets 102. In an implementation, the correlation of the radar range resolution (Rr) and the range-profiles (RP) of the corresponding echoes from the one or more targets 102 may be based on a condition that the radar range resolution (Rr) should be greater than a difference between range-profiles (RP) of the two echoes. In an implementation, the each range-profile (RP) may be associated with a corresponding target index and a corresponding transceiver index. In an implementation, the radar range resolution (Rr) may be associated with the corresponding signal bandwidth.
In an implementation, as also referred to in Figure 3, the target index (tn) may be referred to as a unique identifier assigned to each target 102 detected by the each radar transceiver 104. For instance, the radar transceiver 104a may detect one or more targets (t0, t1, ... tn) 102 in the FOV (in Figure 1), and each target (tn) may be assigned an index (0, 1, 2, 3….n) to keep track of the characteristics such as range, velocity, and direction across successive scans. The index allows the radar transceiver 104a to correlate measurements from multiple radar pulses and track the movement of each target (t0, t1, ... tn) 102 over time.
In an implementation, as also referred to in Figure 3, the transceiver index (Rn) may be referred to as an identifier used to distinguish between different radar transceivers 104 for detecting signals from different directions or locations. Each radar transceiver 104 may be assigned a unique transceiver index (R1, R2, … Rn) to identify which of the radar transceivers 104 received the signal from the particular target (t0, t1, ... tn) 102. In the present scenario, radar transceivers (R1, R2, and R3) 104 are depicted in Figure 3.
In an embodiment, the at least one processor 404 may be configured to further determine whether the measured range-profiles (RP) corresponding to at least two echoes belong to either a same target or different targets amongst the one or more targets (t0, t1, ... tn) 102 based on the correlation. In an implementation, for at least two echoes that belong to the same target (for example, t0), the at least one processor 404 may be configured to estimate range-profiles (RP) corresponding to one or more grid locations based at least on an average of range-profiles (RP). In another implementation, for at least two echoes that belong to the same target, the at least one processor may be configured to determine a minimum error margin based on a comparison of the measured range-profile (RP) with the estimated range-profiles (RP). The at least one processor 404 may be configured to further determine the one or more grid locations associated with the one or more targets based at least on the determined minimum error margin associated with the same target, and the measured range-profiles (RP) corresponding to at least two echoes that belong to the different targets. The at least one processor 404 may be configured to further plot the 3D images representing at least a corresponding range, a corresponding elevation, and a corresponding azimuth of the one or more targets based on the determined one or more grid locations associated with the one or more targets.
In an embodiment, upon determining that the measured range-profiles (RP) corresponding to at least two echoes belong to the same target (for example, t0), the at least one processor 404 may be configured to determine the average range-profile (RPavg) with a tolerance of radar range resolution (Rr) corresponding to at least the two echoes belonging to the same target (t0) amongst the one or more targets (t0, t1, ... tn) 102. The at least one processor 404 may be configured to further determine one or more grid locations associated with the determined average range-profile (RPavg) with the tolerance of radar range resolution (Rr). In a non-limiting example, if the radar range resolution is 15 cm (for 1 GB bandwidth), then the smallest possible grid length in any dimension would be 15 cm. If a room is 1.5m long in that dimension, then the largest possible number of grids in that dimension would be 10. The at least one processor 404 may be configured to estimate the range-profiles (RP) corresponding to the determined one or more grid locations and accordingly, determine the minimum error margin based on a comparison of the measured range-profile (RP) with the estimated range-profiles (RP) corresponding to the determined one or more grid locations. Furthermore, the one or more grid locations associated with the same target may be determined based on the determined minimum error margin.
In an embodiment, the at least one processor 404 may be configured to iteratively measure the range-profiles (RP) associated with a selected target index corresponding to the one or more targets.
In an advantageous aspect of the present disclosure, a solution to the challenge of generating real-time 3D images of the one or more targets 102 in a target space by radar transceivers 104 is disclosed, leveraging the range-profile (RP) from each of the plurality of channels and the predetermined locations of the antennas 402 (as shown in Figure 4) as a foundational reference. By segmenting the target space into a grid structure, each radar transceiver 104 may employ a systematic search and analysis approach to accurately estimate the positions of the one or more targets (t0, t1, ... tn) 102 within the target space. In another advantageous aspect, the subsequent identification of range-profiles (RP) from distinct radar transceivers 104 may be attributed to the same target (t0, t1, ... tn) 102 (for example, t0). In another advantageous aspect, the scanning of pertinent grid locations based on the identification of the range-profiles (RP) of each target (t0, t1, ... tn) 102 in the target space may be employed. The scanning of pertinent grid locations may help in ascertaining the minimum error margin between the range-profiles (RP) extrapolated from grid locations and those derived directly from real-time echoes from one or more targets (t0, t1, ... tn) 102. Further, the minimum error margin identified may help in determining the plausible target locations within the grid-spaces.
In an embodiment, to mitigate the complexities associated with real-time 3D radar imaging, and to ensure time and memory efficiency, a unique asymmetric positioning of the radar transceiver’s 104 antennae 402 may be employed on the azimuth-elevation plane, with each antenna 402 functioning in both transmit and receive modes. The minimum inter-antenna distance may be carefully defined to be at least equal to the radar’s range resolution (Rr), underpinning the radar transceiver’s 104 efficacy in plotting precise 3D images of the each detected target (t0, t1, ... tn) 102. In an advantageous aspect, the mechanism used for plotting the 3D images of the one or more targets (t0, t1, ... tn) 102 may be unique due to the use of signal processing and geometry for identifying the grid locations associated with the one more targets (t0, t1, ... tn) 102.
Figure 5 illustrates a method 500 for plotting the 3D images of one or more targets, according to an embodiment of the present disclosure.
At step 502, the radar transceiver 104 may transmit signals to monitor the presence of the one or more target 102 in the vicinity, which may get reflected back from the target 102. The echoes corresponding to the reflected signal from the one or more targets 102 may be received through the plurality of channels at the plurality of radar transceivers 104.
At step 504, the range-profile (RP) associated with the received echoes from the one or more targets may be measured at each radar transceiver104 of the plurality of radar transceivers 104.
In an implementation, the measuring in step 504 associated with the received echoes from the one or more targets at each radar transceiver104 of the plurality of radar transceivers 104 may include iteratively measuring the range-profiles (RP) associated with a selected target index corresponding to the one or more targets.
At step 506, a radar range resolution (Rr) and the range-profiles (RP) of the corresponding echoes from the one or more targets 102 may be correlated based on a condition that the radar range resolution (Rr) is greater than a difference between range-profiles (RP) of the two echoes.
At step 508, a condition may be determined whether the measured range-profiles (RP) corresponding to at least two echoes belong to either the same target or different targets amongst the one or more targets based on the correlation.
At step 510, if two echoes belong to the same target, range-profiles (RP) corresponding to one or more grid locations based at least on an average of range-profiles (RP) may be determined.
In an implementation, upon determining that the measured range-profiles (RP) corresponding to at least two echoes belong to the same target, the method may include determining the average range-profile (RP) with a tolerance of radar range resolution (Rr) corresponding to at least the two echoes belonging to the same target amongst the one or more targets.
In another implementation, the method may further involve determining one or more grid locations associated with the determined average range-profile (RP) with the tolerance of radar range resolution (Rr).
At step 512, a minimum error margin based on a comparison of the measured range-profile (RP) with the estimated range-profiles (RP) may be determined.
In another implementation, the method may further involve estimating range-profiles (RP) corresponding to the determined one or more grid locations. In another implementation, the method may further involve determining the minimum error margin based on a comparison of the measured range-profile (RP) with the estimated range-profiles (RP) corresponding to the determined one or more grid locations. In another implementation, the method may further involve determining, based on the determined minimum error margin, the one or more grid locations associated with the same target.
At step 514, the one or more grid locations associated with the one or more targets may be determined. In an implementation, the one or more grid locations associated with the one or more targets may be determined based on the determined minimum error margin associated with the same target and the measured range-profiles (RP) corresponding to at least two echoes that belong to the different targets.
At step 516, the 3D images representing at least a corresponding range, a corresponding elevation, and a corresponding azimuth of the one or more targets 102 may be plotted based on the determined one or more grid locations associated with the one or more targets.
Figure 6a illustrates an exemplary flow chart indicating the calculations done in each receiver channel with respect to each possible pair of detected targets, according to an exemplary implementation of the present disclosure.
In an implementation, the flowchart may represent the radar signal processing steps. The steps 601-622 processes the plurality of channels to detect the targets. Further, the difference between the range-profiles (RP) may be calculated to determine valid target locations. The process may iterate through all detected targets (t0, t1, ... tn) 102 and a threshold may be checked, that is whether Diff(y) is less than Rn. The process may loop through all the radar transceivers 104 before terminating.
At step 601, the radar transceiver (for example, R1) 104 may collect channel data in the determined format, the channel data may be processed to detect one or more targets (t0, t1, ... tn) 102. The step 601 corresponds to step 502 of Figure 5, which is receiving echoes from the one or more targets from the plurality of channels. Thus, the channel data may be related to echoes.
At step 602, the radar transceiver(R1) 104 may compute the range-profile ?RP?_(target_index)^(receiver_index) for the plurality of channels 102. The step 602 corresponds to step 504 of Figure 5, that is, at each radar transceiver of the plurality of radar transceivers, the range-profile (RP) associated with the received echoes from the one or more targets may be measured.
At step 603, the at least one target corresponding to the radar transceiver(R1) 104 may be initialized to determine the process. The channel index may be represented by “n”.
At step 604, the total number of target locations (T) may be determined in the nth radio transceiver’s 104 range-profile ?RP?_(target_index)^(receiver_index).
At step 605 and step 606, the process corresponding to the detected target location (T) may be initialized, which is represented as t0=0 and t1=0, respectively, where t0 and t1 represent the indices for the detected target locations.
At step 607, a difference (Diffy(y(t0, t1))) between the range-profiles (RP) at different target locations t and t0 may be computed as follows:
Diffy(y(n,t0,t1))=|?RP?_t0^n- ?RP?_t1^n | (1)
At step 608, a condition may be checked, if t1 = = t0, that is, whether the same target location is being compared.
If the condition is satisfied, the process may continue to the next step, otherwise, step 607 may be reiterated. The step 607 may be conducted to calculate the difference between the range-profiles coming from the same receiver channel but not necessarily the same target. In the case of information coming from the same target, the calculated difference becomes zero.
At step 609, a condition is checked if the computed difference (Diffy(y(n, t0, t1))) is less than the range resolution (Rr), that is if the difference is below a threshold of the range resolution (Rr).
At step 610, if the condition of step 609 is not satisfied, the path leading to decision block A may be followed in the subsequent flowchart as shown in Figure 6.
At step 611, if the condition of step 609 is satisfied, the process may end.
At steps 612, the t1 may be incremented by 1, to continue the process.
At step 613, the conditions may be checked that if the t1 is less than T or not.
At step 614, if the condition in step 613 is not satisfied, the t0 may be incremented with 1.
At step 621 and step 622, if the condition in step 613 is satisfied, the process may be reiterated back from step 607, with incremented t1.
At step 615, a condition is checked whether t0 is less than T.
At step 619 and step 620, if the condition in step 615 is satisfied, the process from step 106 may be reiterated with incremented t0.
At step 616, if the condition in step 615 is not satisfied, the value of n may be incremented by 1.
At step 617, a condition may be checked that whether n is less than the number of transceiver channels (NRx). The condition may help in determining whether there are more channels to the process. If the condition is satisfied, further steps may be followed, otherwise, the process may end at step 118.
At step 618, the process may end.
Figure 6b illustrates a flow chart, in furtherance to Figure 6a, indicating the calculations done by considering all relevant locations grids within the radar detection space, according to an exemplary implementation of the present disclosure.
Referring to Figure 6b, the flowchart through steps 701-714 relates to computing the range-profile (RP) and comparing the difference between them based on certain conditions.
At step 701, the process may begin from a previous step labeled A.
At step 702, step 703, and step 704, three indices [nx, ny, and nz] may be initialized to zero, respectively.
At step 705, the range-profile (?RP?_(target_index)^(receiver_index)) of the each channel corresponding to the radar transceiver (for example, R1) 104 may be determined based on the center of the grid identified by the indices [nx, ny, and nz].
The?RP?_(target_index)^(receiver_index) may be calculated as:
?RP?_(target_index)^(receiver_index)?(?RP?_(t0 )^n+?RP?_(t1 )^n)/2±Rr (2)
From equation 2, the value of the range-profile (RP) at the radar transceiver (R1) 104 may be derived based on the target index and another RP value. The step 705 corresponds to step 508 of Figure 5, that is, the radar range resolution (Rr) and range-profiles (RP) of the corresponding echoes from the one or more targets may be correlated.
At step 706, various differences (Diffy1(n, nx, ny, nz, t0), Diffy2(n, nx, ny, nz, t1), Diffy3(n, nx, ny, nz, t0, t1), and Diffy4(n, nx, ny, nz, t0, t1)) may be computed as follows:
Diffy1(n, nx, ny, nz, t0) = |?RP?_(nx,ny,nz)^n- ?RP?_t0^n | (3)
Diffy2(n, nx, ny, nz, t1) = |?RP?_(nx,ny,nz)^n- ?RP?_t1^n | (4)
Diffy3(n, nx, ny, nz, t0, t1) = | Diffy(n, t0, t1) – Diffy1(n, nx, ny, nz, t0)| (5)
Diffy4(n, nx, ny, nz, t0, t1) = | Diffy(n, t0, t1) – Diffy2(n, nx, ny, nz, t1)| (6)
Equations 5 and 6 depict that Diffy3 and Diffy4 may involve further computation based on Diffy1 and Diffy2.
At step 707, a condition for further processing may be determined, which involves comparing Diffy3 with Diffy4, which may lead to a target match. The step 707 may correspond to step 510 of Figure 5, where the range-profiles (RP) corresponding to one or more grid locations based at least on the average of range-profiles (RP) may be estimated.
At step 708, if the condition in step 707 satisfies the target, t1 may be identified.
At step 709, if the condition in step 707 is not satisfied, target t0 may be identified.
At step 710, a condition for further processing may be determined, that is, if nz is less than NZ.
At step 711, if the condition in step 710 is satisfied, nz may be incremented by 1.
If the condition in step 710 is not satisfied, step 712 may be followed.
At step 712, a condition for further processing may be determined, that is, if ny is less than NY.
At step 713, if the condition in step 712 is satisfied, ny may be incremented by 1.
If the condition in step 712 is not satisfied step 714 may be followed.
At step 714, a condition for further processing may be determined, that is, if nx is less than NX.
At step 715, if the condition in step 714 is satisfied, nx may be incremented by 1
Thus, if the above conditions in steps 710, 712, and 714 are met, nz, ny, and nz may be incremented sequentially.
If the condition in step 714 is not satisfied the flowchart may move to step B, indicating the transition to another process as depicted in Figure 6c.
Thus, the flow chart in Figure 6b renders the process in indicating the calculations done by considering all relevant locations grids within the radar detection space with respect to each data point obtained from the steps in Figure 6, according to an exemplary implementation of the present disclosure.
Referring to Figure 6b, the choice of grid locations that may contain the targets may be done with the help of the detected target ranges obtained from the radar transceiver’s 104 range-profiles (RP). A creation of phantom range-profiles (RP) for each radar transceiver 104 may be carried out by assuming each grid location to be the target location. The same grid-location therefore may give rise to different range-profiles (RP) for different radar transceivers 104. Steps 701-704 may be used for initializing the relevant variables which may affect scanning of the grids. Then, the range-profiles (RP) of the radar transceivers 104 relating to the phantom targets may be created so that the condition illustrated in step 705 may be satisfied. The calculations done in step 706 may be used in later stages. These calculations essentially amount to a process to decide the error margin between the real-time range-profiles (RP) of the radar transceivers 104 and the range-profiles (RP) resulting from the phantom targets placed in the grid locations. The minimum error margin may determine the grid location where the target may be located. Such search for minimum error margin is conducted in step 707 where two variables calculated in the previous steps may be compared and a decision regarding the potential location of the target within the grid space may be taken (steps 708 and 709). Steps 710-715 may help in scanning the grid-space and step 716 may send control to B in Figure 6c.
Figure 6c illustrates a flow chart, in furtherance to Figure 6b, for determining the most probable range-profile ([X, Y, Z] or [Range, Azimuth, Elevation] coordinates) for any given target index, according to an exemplary implementation of the present disclosure.
Referring to Figure 6c, the flow chart represents a process for determining the range-profile (RP) for each channel corresponding to the radar transceiver 104 and identifying the minimum difference index across multiple transceivers 104.
At step 801, the process may begin from a previous step labeled B.
At step 802, the range-profile (RP) for each channel may be determined as ?DRP?_(target_index)^(receiver_index). The determined number of targets (DT) may be computed based on the minimum value among different radar transceiver’s 104 DT value.
DT = min( ?DT?_(receiver_1),?DT?_(receiver_2),….,?DT?_(receiver_NRx )) (7)
At step 803, a counter ti may be initiated with 0, the counter ti may be iterated through detected targets.
At step 804, the DRP values from all the radar transceivers 104 at the current iteration ti may be analyzed. The minimum difference index may be computed as follows:
?DRP?_ti^(All_receiver)=min?_difference_index (|?RP?_t^(receiver_1 )- ?DRP?_ti^(receiver_1 ) |,|?RP?_ti^(receiver_2 )- ?DRP?_ti^(receiver_2 ) |,… |?RP?_ti^(receiver_NRx )- ?DRP?_ti^(receiver_NRx ) |) (8)
Thus, steps 802-804 correspond to steps 512-514 of Figure 5, where the minimum error margin based on the comparison of the measured range-profile (RP) with the estimated range-profiles (RP) is determined and accordingly, the one or more grid locations associated with the one or more targets are determined.
At step 805, a condition may be checked, if the ti is less than DT.
At step 806, if the condition in step 805 satisfies, the value of ti may be incremented by 1 and the process from step 304 may be iterated with incremented ti.
At step 807, if the condition in step 805 is not satisfied, the process ends.
Thus, the flow chart in Figure 6c may help in determining the most probable range-profile ([X, Y, Z] or [Range, Azimuth, Elevation] coordinates) for any given target index, These target indices may be chosen based on the range resolution (Rr) separation between detections. In step 801, the data may be passed through to generate relevant parameters shown in step 802. A conditional loop runs using steps 803-807 which may help in determining the most probable range-profile (RP) for the given target index. The minimum error margin between the measured and observed slant range may be considered as the appropriate metric.
In an advantageous aspect, a pivotal aspect of the present disclosure is an emphasis on optimizing the time and memory demands inherent to the process, thereby significantly enhancing the feasibility of its practical, real-time application.
In an advantageous aspect, the present disclosure pertains to a method for constructing 3D images that depict the elevation, azimuth angle, and range of targets detected by the radar transceiver 104, utilizing the output data derived from the radar transceiver 104. The present method is specifically designed for implementation in radar transceivers 104 equipped with more than two receiver channels, each channel characterized by its unique range-profile (RP). The core of the present disclosure involves the reception of digitized outputs from the plurality of channels (range-profiles) of the radar transceiver 104, followed by the processing of this received data to generate 3D images. These images accurately represent the spatial location of detected targets within a confined area demarcated by the radar transceiver’s FOV, delineating the targets’ positions in terms of range, and their elevation and azimuth angles relative to the radar transceiver 104. The disclosed method facilitates an enhanced understanding and visualization of the radar transceiver 104 detected environment by providing precise 3D representations of target locations, thereby significantly improving the radar transceiver’s 104 utility for applications requiring detailed spatial awareness of the observed area.
In another advantageous aspect of the present invention, the misidentification of one or more targets 102 is eventually resolved by the method and radar transceiver 104 to better handle large, complex targets and to correlate overlapping data from multiple radar transceivers 104.
While specific language has been used to describe the disclosure, any limitations arising on account of the same are not intended. As would be apparent to a person in the art, various working modifications may be made to the method in order to implement the inventive concept as taught herein.
The drawings and the forgoing description give examples of embodiments. Those skilled in the art will appreciate that one or more of the described elements may well be combined into a single functional element. Alternatively, certain elements may be split into multiple functional elements. Elements from one embodiment may be added to another embodiment. For example, orders of processes described herein may be changed and are not limited to the manner described herein.
,CLAIMS:
1. A method (500) for plotting three-dimensional (3D) images of one or more targets, comprising:
receiving (502), through a plurality of channels, echoes from the one or more targets at a plurality of radar transceivers;
measuring (504), at each radar transceiver of the plurality of radar transceivers, a range-profile (RP) associated with the received echoes from the one or more targets;
correlating (506)a radar range resolution (Rr) and range-profiles (RP) of the corresponding echoes from the one or more targets;
determining (508) whether the measured range-profiles (RP) corresponding to at least two echoes belong to either same target or different targets amongst the one or more targets based on the correlation, wherein for at least two echoes that belong to the same target:
estimating (510) range-profiles (RP) corresponding to one or more grid locations based at least on an average of range-profiles (RP); and
determining (512) a minimum error margin based on a comparison of the measured range-profile (RP) with the estimated range-profiles (RP);
determining (514) the one or more grid locations associated with the one or more targets based at least on one of:
the determined minimum error margins associated with the same target; and
the measured range-profiles (RP) corresponding to at least two echoes that belong to the different targets; and
plotting (516) the 3D images representing at least a corresponding range, a corresponding elevation, and a corresponding azimuth of the one or more targets based on the determined one or more grid locations associated with the one or more targets.

2. The method (500) as claimed in claim 1, wherein correlating the radar range resolution (Rr) and range-profiles (RP) of the corresponding echoes from the one or more targets based on a condition that the radar range resolution (Rr) is greater than a difference between range-profiles (RP) of the two echoes, wherein:
the each range-profile (RP) is associated with a corresponding target index and a corresponding transceiver index, and
the radar range resolution (Rr) is associated with a corresponding signal bandwidth.

3. The method (500) as claimed in claim 1, wherein upon determining that the measured range-profiles (RP) corresponding to at least two echoes belonging to the same target, the method includes:
determining the average range-profile (RP) with a tolerance of radar range resolution (Rr) corresponding to at least the two echoes belonging to the same target amongst the one or more targets,
determining one or more grid locations associated with the determined average range-profile with the tolerance of radar range resolution (Rr);
estimating range-profiles (RP) corresponding to the determined one or more grid locations;
determining the minimum error margin based on a comparison of the measured range-profile (RP) with the estimated range-profiles (RP) corresponding to the determined one or more grid locations; and
determining, based on the determined minimum error margin, the one or more grid locations associated with the same target.

4. The method (500) as claimed in claim 1, wherein the plurality of radar transceivers are situated asymmetrically on an azimuth-elevation plane and a distance between the two successive radar transceivers is at least equal to the radar range resolution (Rr).

5. The method (500) as claimed in claim 1, wherein the measuring associated with the received echoes from the one or more targets at each radar transceiver of the plurality of radar transceivers includes iteratively measuring the range-profiles (RP) associated with a selected target index corresponding to the one or more targets.

6. The method (500) as claimed in claim 1, wherein the each radar transceiver comprises at least three channels for receiving echoes from the one or more targets.

7. A radar transceiver (104) for plotting three-dimensional (3D) images of one or more targets, comprising:
a plurality of channels configured to receive echoes from the one or more targets;
at least one processor (404) in communication with a memory (406), the at least one processor (404) configured to:
measure a range-profile (RP) associated with the received echoes from the one or more targets;
correlate a radar range resolution (Rr) and range-profiles (RP) of the corresponding echoes from the one or more targets;
determine whether the measured range-profiles (RP) corresponding to at least two echoes belong to either a same target or different targets amongst the one or more targets based on the correlation, wherein for at least two echoes that belong to the same target, the at least one processor (404) is configured to:
estimate range-profiles (RP) corresponding to one or more grid locations based at least on an average of range-profiles (RP); and
determine a minimum error margin based on a comparison of the measured range-profile (RP) with the estimated range-profiles (RP);
determine the one or more grid locations associated with the one or more targets based at least on one of:
the determined minimum error margins associated with the same target; and
the measured range-profiles (RP)corresponding to at least two echoes that belong to the different targets; and
plot the 3D images representing at least a corresponding range, a corresponding elevation, and a corresponding azimuth of the one or more targets based on the determined one or more grid locations associated with the one or more targets.

8. The radar transceiver (500) as claimed in claim 7, wherein the at least one processor (404) is configured to correlate the radar range resolution (Rr) and range-profiles (RP) of the corresponding echoes from the one or more targets based on a condition that the radar range resolution (Rr) is greater than a difference between range-profiles of the two echoes, wherein:
the each range-profile (RP) is associated with a corresponding target index and a corresponding transceiver index, and
the radar range resolution (Rr) is associated with a corresponding signal bandwidth.

9. The radar transceiver (500) as claimed in claim 7, wherein upon determining that the measured range-profiles (RP) corresponding to at least two echoes belonging to the same target, the at least one processor (404) is configured to:
determine the average range-profile (RP) with a tolerance of radar range resolution (Rr) corresponding to at least the two echoes belonging to the same target amongst the one or more targets,
determine one or more grid locations associated with the determined average range-profile (RP) with the tolerance of radar range resolution (Rr);
estimate range-profiles (RP) corresponding to the determined one or more grid locations;
determine the minimum error margin based on a comparison of the measured range-profile (RP) with the estimated range-profiles (RP) corresponding to the determined one or more grid locations; and
determine, based on the determined minimum error margin, the one or more grid locations associated with the same target.

10. The radar transceiver (500) as claimed in claim 7, wherein the at least one processor (404) is configured to iteratively measure the range-profiles (RP)associated with a selected target index corresponding to the one or more targets.