RADAR SYSTEM AND METHOD WITH AUXILIARY CHANNEL FOR INTERFERENCE DETECTION

Abstract

A radar system for monitoring a region of interest including a receiving antenna arrangement for receiving signals from a region of interest and a receiver signal processing arrangement for processing received signals. The radar system further includes at an auxiliary channel antenna arrangement for receiving signals from at least the region of interest and with a sensing characteristic for received signals which is mutually different to that of the receiving antenna arrangement. The receiver signal processing arrangement is operable to process the received signals from the receiving antenna arrangement and the auxiliary channel antenna arrangement to discriminate a jamming and/or interfering source in or near the region of interest.

Claims

1. A radar system (10) for monitoring a region of interest (ROI, 20), wherein the radar system (10) includes a transmitter signal processing arrangement (40) for generating signals for an emitting antenna arrangement (30) to emit as electromagnetic radar radiation (35) to the region of interest (ROI, 20), wherein the transmitter signal processing arrangement (40) is configured to employ frequency hopping in operation, and a receiving antenna arrangement (50) for receiving reflected electromagnetic radar radiation (45) from the region of interest (ROI, 20) and a receiver signal processing arrangement (60) for processing received signals corresponding to the reflected electromagnetic radar radiation (45) from one or more objects (70) in the region of interest (ROI, 20), wherein: (i) the radar system (10) includes at least one auxiliary channel antenna arrangement (80) for receiving signals from at least the region of interest (ROI, 20), wherein the auxiliary channel antenna arrangement (80) and the receiving antenna arrangement (50) are mounted such that their axes are offset by an non-zero angle, and wherein the at least one auxiliary channel antenna arrangement (80) has a sensing characteristic which is mutually different to that of the receiving antenna arrangement (50); and (ii) the receiver signal processing arrangement (60) is configured to process the received signals from the receiving antenna arrangement (50) and from the at least one auxiliary channel antenna arrangement (80), and to discriminate therefrom one or more signals corresponding to a jamming and/or an interfering source (90) in or near the region of interest (ROI, 20) from the received signals from the receiving antenna arrangement (50).

2. The radar system (10) as claimed in claim 1, wherein the transmitter signal processing arrangement (40), for generating signals to be emitted in operation as corresponding electromagnetic radar radiation (35) from the emitting antenna arrangement (30), is configured to generate chirp signals when in operation.

3. The radar system (10) as claimed in claim 2, wherein the chirp signals, to be emitted in operation as corresponding electromagnetic radar radiation (35) from the emitting antenna arrangement (30), are chirped in a range of 100 MHz to 500 MHz, and more optionally substantially 300 MHz.

4. The radar system (10) as claimed in claim 3, characterized wherein the radar system (10) is configured to vary a centre frequency of the chirp signals.

5. The radar system (10) as claimed in claim 4, wherein the radar system (10) is configured to vary the centre frequency of the chirp signals in at least one of following temporally-varying frequency patterns: (a) a pre-determined manner; (b) a frequency swept manner; and (c) an adaptive manner, wherein the centre frequency is varied depending upon a degree of interference suppression exhibited by the radar system (10).

6. The radar system (10) as claimed in claim 1, wherein the transmitter signal processing arrangement (40) for generating signals to be emitted in operation as corresponding electromagnetic radar radiation (35) from the emitting antenna arrangement (30) is configured to employ temporally pseudo-random frequency hopping in operation.

7. The radar system (10) as claimed in claim 1, wherein the emitting antenna arrangement (30) is configured to emit the electromagnetic radar radiation (35) in a range of 10 GHz to 200 GHz, and more optionally at substantially 24 GHz or substantially 77 GHz.

8. A method (100) of using a radar system (10) for monitoring a region of interest (ROI, 20), wherein the radar system (10) includes a transmitter signal processing arrangement (40) for generating signals to be emitted in operation as corresponding electromagnetic radar radiation (35) from an emitting antenna arrangement (30) to the region of interest (ROI, 20), wherein the transmitter signal processing arrangement (40) is configured to employ frequency hopping in operation, and a receiving antenna arrangement (50) for receiving reflected electromagnetic radar radiation (45) from the region of interest (ROI, 20) and a receiver signal processing arrangement (60) for processing received signals corresponding to the reflected electromagnetic radar radiation (45) from one or more objects (70) in the region of interest (ROI, 20), wherein the method includes: (i) arranging for the radar system (10) to include at least one auxiliary channel antenna arrangement (80) for receiving signals from at least the region of interest (ROI, 20), wherein the auxiliary channel antenna arrangement (80) and the receiving antenna arrangement (50) are mounted such that their axes are offset by an non-zero angle, and wherein the at least one auxiliary channel antenna arrangement (80) has a sensing characteristic which is mutually different to that of the receiving antenna arrangement (50); and (ii) operating the receiver signal processing arrangement (60) to process the received signals from the receiving antenna arrangement (50) and from the at least one auxiliary channel antenna arrangement (80) and to discriminate therefrom one or more signals corresponding to a jamming and/or an interfering source (90) in or near the region of interest (ROI, 20) from the received signals from the receiving antenna arrangement (50).

9. The method (100) as claimed in claim 8, wherein the method (100) includes arranging for the transmitter signal processing arrangement (40) for generating signals, to be emitted in operation as corresponding electromagnetic radar radiation (35) from the emitting antenna arrangement (30), to be operable to generate chirp signal in operation.

10. The method (100) as claimed in claim 9, wherein the method (100) includes arranging for the signals, to be emitted in operation as corresponding electromagnetic radar radiation (35) from the emitting antenna arrangement (30), to be chirped in a range of 100 MHz to 500 MHz, and more optionally substantially 300 MHz.

11. The method as claimed in claim 10, wherein the method includes operating the radar system (10) to vary a centre frequency of the chirp signals.

12. The method as claimed in claim 11, wherein the method includes operating the radar system (10) to vary the centre frequency of the chirp signals in at least one of following temporally-varying frequency patterns: (a) a pre-determined manner; (b) a frequency swept manner; and (c) an adaptive manner, wherein the centre frequency is varied depending upon a degree of interference suppression exhibited by the radar system (10).

13. The method (100) as claimed in claim 8, wherein the method (100) includes arranging for the transmitter signal processing arrangement (40) for generating signals, to be emitted in operation as corresponding electromagnetic radar radiation (35) from the emitting antenna arrangement (30), to be operable to employ temporally pseudo-random frequency hopping in operation.

14. The method (100) as claimed in claim 8, wherein the method (100) includes arranging for the emitting antenna arrangement (30) to be operable to emit the electromagnetic radar radiation (35) in a range of 10 GHz to 200 GHz, and more optionally at substantially 24 GHz or substantially 77 GHz.

15. A computer program product comprising a non-transitory computer-readable storage medium having computer-readable instructions stored thereon, the computer-readable instructions being executable by a computerized device comprising processing hardware to execute the method (100) as claimed in claim 8.

Description

DESCRIPTION OF THE DIAGRAMS

[0054] Embodiments of the present disclosure will now be described, by way of example only, with reference to the following diagrams wherein:

[0055] FIG. 1 is a schematic illustration of a radar system pursuant to the present disclosure, wherein the radar system utilizes an addition of an auxiliary channel when in operation; and

[0056] FIG. 2 is a flow chart of steps of a method of operating the radar system of FIG.

[0057] In the accompanying diagrams, an underlined number is employed to represent an item over which the underlined number is positioned or an item to which the underlined number is adjacent. A non-underlined number relates to an item identified by a line linking the non-underlined number to the item. When a number is non-underlined and accompanied by an associated arrow, the non-underlined number is used to identify a general item at which the arrow is pointing.

DESCRIPTION OF EMBODIMENTS

[0058] According to a first aspect, there is provided a radar system for monitoring a region of interest (ROI), wherein the radar system includes a transmitter signal processing arrangement for generating signals for an emitting antenna arrangement to emit as electromagnetic radar radiation to the region of interest (ROI), wherein the transmitter signal processing arrangement is operable to employ frequency hopping in operation, and a receiving antenna arrangement for receiving reflected electromagnetic radar radiation from the region of interest (ROI) and a receiver signal processing arrangement for processing received signals corresponding to the reflected electromagnetic radar radiation from one or more objects in the region of interest (ROI), characterized in that: [0059] (i) the radar system includes at least one auxiliary channel antenna arrangement for receiving signals from at least the region of interest (ROI), wherein the auxiliary channel antenna arrangement and the receiving antenna arrangement are mounted such that their axes are offset by an non-zero angle, and wherein the at least one auxiliary channel antenna arrangement has a sensing characteristic which is mutually different to that of the receiving antenna arrangement; and [0060] (ii) the receiver signal processing arrangement is operable to process the received signals from the receiving antenna arrangement and from the at least one auxiliary channel antenna arrangement, and to discriminate therefrom one or more signals corresponding to a jamming and/or an interfering source in or near the region of interest (ROI) from the received signals from the receiving antenna arrangement.

[0061] The radar system is of advantage in that different relative responses of the receiving antenna arrangement and the at least one auxiliary channel antenna arrangement enables potentially interfering sources of radiation to be discriminated from reflected signals arising from objects within the region of interest (ROI).

[0062] Optionally, in the radar system, the transmitter signal processing arrangement, for generating signals to be emitted in operation as corresponding electromagnetic radar radiation from the emitting antenna arrangement, is operable to generate chirp signals when in operation. More optionally, in the radar system, the chirp signals, to be emitted in operation as corresponding electromagnetic radar radiation from the emitting antenna arrangement, are chirped in a range of 100 MHz to 500 MHz, and more optionally substantially 300 MHz.

[0063] More optionally, the radar system is operable to vary a centre frequency of the chirp signals. More optionally, the radar system is operable to vary the centre frequency of the chirp signals in at least one of following temporally-varying frequency patterns: [0064] (a) a pre-determined manner; [0065] (b) a frequency swept manner; and [0066] (c) an adaptive manner, wherein the centre frequency is varied depending upon a degree of interference suppression exhibited by the radar system.

[0067] Optionally, in the radar system, the transmitter signal processing arrangement for generating signals to be emitted in operation as corresponding electromagnetic radar radiation from the emitting antenna arrangement is operable to employ temporally pseudo-random frequency hopping in operation.

[0068] Optionally, in the radar system, the emitting antenna arrangement is operable to emit the electromagnetic radar radiation in a range of 10 GHz to 200 GHz, and more optionally at substantially 24 GHz or substantially 77 GHz.

[0069] According to a second aspect, there is provided a method of using a radar system for monitoring a region of interest (ROI), wherein the radar system includes a transmitter signal processing arrangement for generating signals to be emitted in operation as corresponding electromagnetic radar radiation from an emitting antenna arrangement to the region of interest (ROI), wherein the transmitter signal processing arrangement is operable to employ frequency hopping in operation, and a receiving antenna arrangement for receiving reflected electromagnetic radar radiation from the region of interest (ROI) and a receiver signal processing arrangement for processing received signals corresponding to the reflected electromagnetic radar radiation from one or more objects in the region of interest (ROI), characterized in that the method includes: [0070] (i) arranging for the radar system to include at least one auxiliary channel antenna arrangement for receiving signals from at least the region of interest (ROI), wherein the auxiliary channel antenna arrangement and the receiving antenna arrangement are mounted such that their axes are offset by an non-zero angle, and wherein the at least one auxiliary channel antenna arrangement has a sensing characteristic which is mutually different to that of the receiving antenna arrangement; and [0071] (ii) operating the receiver signal processing arrangement to process the received signals from the receiving antenna arrangement and from the at least one auxiliary channel antenna arrangement and to discriminate therefrom one or more signals corresponding to a jamming and/or an interfering source in or near the region of interest (ROI) from the received signals from the receiving antenna arrangement.

[0072] Optionally, the method includes arranging for the transmitter signal processing arrangement for generating signals, to be emitted in operation as corresponding electromagnetic radar radiation from the emitting antenna arrangement, to be operable to generate chirp signal in operation. More optionally, the method includes arranging for the signals, to be emitted in operation as corresponding electromagnetic radar radiation from the emitting antenna arrangement, to be chirped in a range of 100 MHz to 500 MHz, and more optionally substantially 300 MHz.

[0073] Optionally, the method includes operating the radar system to vary a centre frequency of the chirp signals. More optionally, the method includes operating the radar system to vary the centre frequency of the chirp signals in at least one of following temporally-varying frequency patterns: [0074] (a) a pre-determined manner; [0075] (b) a frequency swept manner; and [0076] (c) an adaptive manner, wherein the centre frequency is varied depending upon a degree of interference suppression exhibited by the radar system.

[0077] Optionally, the method includes arranging for the transmitter signal processing arrangement for generating signals, to be emitted in operation as corresponding electromagnetic radar radiation from the emitting antenna arrangement, to be operable to employ temporally pseudo-random frequency hopping in operation.

[0078] Optionally, he method includes arranging for the emitting antenna arrangement to be operable to emit the electromagnetic radar radiation in a range of 10 GHz to 200 GHz, and more optionally at substantially 24 GHz or substantially 77 GHz.

[0079] According to a third aspect, there is provided a method of using a radar system for monitoring a region of interest (ROI), wherein the radar system includes an emitting antenna arrangement for emitting electromagnetic radar radiation to the region of interest (ROI) and a transmitter signal processing arrangement for generating signals to be emitted in operation as corresponding electromagnetic radar radiation from the emitting antenna arrangement, and a receiving antenna arrangement for receiving reflected electromagnetic radar radiation from the region of interest (ROI), and a receiver signal processing arrangement for processing received signals corresponding to the reflected electromagnetic radar radiation from one or more objects in the region of interest (ROI), characterized in that the method includes: [0080] (iii) arranging for the radar system to include at least one auxiliary channel antenna arrangement for receiving signals from at least the region of interest (ROI), wherein the at least one auxiliary channel antenna arrangement has a sensing characteristic which is mutually different to that of the receiving antenna arrangement; and [0081] (iv) operating the receiver signal processing arrangement to process the received signals from the receiving antenna arrangement and from the at least one auxiliary channel antenna arrangement and to discriminate therefrom one or more signals corresponding to a jamming and/or an interfering source in or near the region of interest (ROI) from the received signals from the receiving antenna arrangement.

[0082] Optionally, the method includes arranging for the transmitter signal processing arrangement for generating signals, to be emitted in operation as corresponding electromagnetic radar radiation from the emitting antenna arrangement, to be operable to generate chirp signal in operation.

[0083] Optionally, the method includes arranging for the signals, to be emitted in operation as corresponding electromagnetic radar radiation, from the emitting antenna arrangement, to be chirped in a range of 1 MHz to 1000 Hz, more optionally in a range of 100 MHz to 500 MHz, and yet more optionally substantially 300 MHz.

[0084] Optionally, the method includes arranging for the transmitter signal processing arrangement for generating signals, to be emitted in operation as corresponding electromagnetic radar radiation from the emitting antenna arrangement, to be operable to employ temporally pseudo-random frequency hopping in operation.

[0085] Optionally, the method includes arranging for the emitting antenna arrangement to be operable to emit the electromagnetic radar radiation in a range of 10 GHz to 200 GHz and more optionally at substantially 24 GHz or substantially 77 GHz.

[0086] Optionally, the method includes monitoring one or more obstacles present within the region of interest (ROI), when the region of interest is a pedestrian crossing and/or a railway level-crossing environment.

[0087] According to a fourth aspect, there is provided a computer program product comprising a non-transitory computer-readable storage medium having computer-readable instructions stored thereon, the computer-readable instructions being executable by a computerized device comprising processing hardware to execute aforesaid methods of the disclosure.

[0088] In overview, referring to FIG. 1, embodiments of the present disclosure are concerned with a radar system, indicated by 10, for monitoring a region of interest (ROI) 20, for example a spatial region of the level crossing region of a railway network. The radar system 10 employs a method of detecting interferences in principal directions of operation of the radar system 10, for example in all spatial directions of operation of the radar system 10, via use of several continuous wave (CW) signals. The radar system 10 employs in operation an emitting antenna arrangement 30 for emitting electromagnetic radar radiation 35 to the region of interest (ROI) 20 and a transmitter signal processing arrangement 40 for generating signals to be emitted in operation as corresponding electromagnetic radar radiation 35 from the emitting antenna arrangement 30. The radar system 10 further employs in operation a receiving antenna arrangement 50 for receiving reflected electromagnetic radar radiation 45 from the region of interest (ROI) 20 and a receiver signal processing arrangement 60 for processing reflected radar signals corresponding to the reflected electromagnetic radar radiation 45, where the reflected electromagnetic radar radiation 45 results from reflections of the electromagnetic radar radiation 35 from one or more objects 70 in the region of interest (ROI) 20. In simpler terms, the radar system 10 is operable to employ the signals generated in operation by the transmitter signal processing arrangement 40 to generate electromagnetic radar radiation 35 to emit towards the region of interest (ROI) 20, and to receive the reflected electromagnetic radar radiation 45 from the region of interest (ROI) 20, wherein received signals corresponding to the reflected electromagnetic radar radiation 45 are processed to determine characteristics of one or more objects present in the region of interest (ROI) 20.

[0089] In addition to the emitting antenna arrangement 30 and the receiving antenna arrangement 50, the radar system 10 employs an auxiliary channel antenna arrangement 80 that is operable in an auxiliary channel, also known as a guard channel or a passive guard channel. Optionally, the auxiliary channel antenna arrangement 80 is operable in more than one auxiliary channel in the radar system 10. The auxiliary channel antenna arrangement 80 operates only in the receive mode and the provided channel has a low gain, wide beam width, namely wider than the channels of the emitting antenna arrangement 30 and the receiving antenna arrangement 50 of the radar system 10. Optionally, the auxiliary channel antenna arrangement 80 and the receiving antenna arrangement 50 are mounted so that their respective axes are offset by an non-zero angle, for example a non-zero angle greater than +/5, for example a non-zero angle greater than +/10. Optionally, the non-zero angle is dynamically varied depending upon conditions at a region of interest (ROI) 20 interrogated by the radar system 10, for example as a function of weather conditions, and/or in response to changing complexity of objects present in the region of interest (ROI) 20, for example 10 as function of traffic flow occurring in the region of interest (ROI) 20. In other words, the non-zero angle is varied in an adaptive manner in response to changing weather conditions, and/or in response to changing complexity of objects present in the region of interest (ROI) 20, for example 10 as function of traffic flow occurring in the region of interest (ROI) 20. Such an adaptive manner of changing the non-zero angle is based upon a numerical model hosted by a data processing arrangement, or controlled by a neural network adaptive learning network that is operable to seek a maximum in information content and/or to minimize jamming signals from the region of interest (ROI) 20 as a function of adaptively varying the non-zero angle. Consequently, when the axis of the receiving antenna arrangement 50 is in a horizontal direction, the axis of the auxiliary channel antenna arrangement 80 points, for example, toward the ground at the angle and leads the receiving antenna arrangement 50 by this angle as the antennas are scanned. It is assumed that the interfering signal from a jamming and/or interfering source, hereinafter simply referred to as the jamming source 90, present in the region of interest (ROI) 20; for example a vehicle with automatic brakes present at a level-crossing region, is located somewhere off the receiving antenna arrangement 50, such as in the side-lobes. On account of using such an implementation, the receiving antenna arrangement 50 may receive signals from both the one or more objects 70 and the interfering signals from the jamming source 90; however returns from the interfering signal in the receiving antenna arrangement 50 are weak because of the low side-lobe gain in the direction of the interfering signal. Moreover, it will be appreciated that the signals received by the auxiliary antenna arrangement 80 are primarily from the jamming source 90. In such manner, the auxiliary channel antenna arrangement 80 has a different sensitivity to the received signal, as compared to the receiving antenna arrangement 50, from the one or more objects 70 in the region of interest (ROI) 20, relative to a signal from the jamming source 90.

[0090] The receiver signal processing arrangement 60 is operable to process the received signals from the receiving antenna arrangement 50 and from the auxiliary channel antenna arrangement 80. As aforementioned, by varying the differential response of the received signals from the receiving antenna arrangement 50 and from the auxiliary channel antenna arrangement 80, the radar system 10 is operable to distinguish the jamming source 90 from the one or more objects 70 in the region of interest (ROI) 20. Moreover, the radar system 10 is operable to scan for determining a magnitude, frequency location and direction of the jamming source 90 present within the region of interest (ROI) 20. Using such information, in the radar system 10, the emitting antenna arrangement 30 is operable either to select suitable frequencies for the emitted electromagnetic radar radiation 35 to the region of interest (ROI) 20 and/or the receiver signal processing arrangement 60 is operable to employ interference suppression algorithms for processing received signals corresponding to the reflected electromagnetic radar radiation 45, to suppress the interference due to the jamming source 90 while interrogating the region of interest (ROI) 20 for the one or more objects 70.

[0091] In the radar system 10, the emitting antenna arrangement 30 is operable to emit the electromagnetic radar radiation 35 in a frequency range of 10 GHz to 200 GHz, and more optionally at substantially 24 GHz or substantially 77 GHz. In one example, the emitting antenna arrangement 30 employs an array of antenna elements, namely phased-array arrangement, for emitting the electromagnetic radar radiation 35 for interrogating the region of interest (ROI) 20. Furthermore, the receiving antenna arrangement 50 is operable to receive the reflected electromagnetic radar radiation 45 in a frequency range of 10 GHz to 200 GHz, and more optionally at substantially 24 GHz or substantially 77 GHz. In one example, the receiving antenna arrangement 50 also employs an array of antenna elements for receiving the reflected electromagnetic radar radiation 45 from the region of interest (ROI) 20. Optionally, the emitting antenna arrangement 30 and the receiving antenna arrangement 50 are directional antennas which radiate or receive greater power in specific directions allowing for increased performance and reduced interference from the one or more objects 70, and optionally use a broad beam width that allows for the signal to propagate reasonably well regardless of terrain. Optionally, a same array of antenna elements is employed both for the emitting antenna arrangement 30 and the receiving antenna arrangement 50; in other words, there is employed a transceiver antenna array. The transceiver antenna array is optionally electronically steered by varying in operation a phase and amplitude parameter of each antenna element of such a transceiver antenna array. Alternatively, the emitting antenna arrangement 30 and/or the receiving antenna arrangement 50 are mechanically-steered, for example mounted on rotatable mounts. Optionally, a hybrid combination of electronic and mechanical steering of the antenna arrangements 30, 50 is employed in operation.

[0092] Moreover, in the radar system 10, the transmitter signal processing arrangement 40 and the receiver signal processing arrangement 60 use one or more processors to implement signal processing functions, namely for generating the signals to be emitted as electromagnetic radar radiation 35 and processing the received signals corresponding to the reflected electromagnetic radar radiation 45. For example, the one or more processors are advantageously implemented as one or more reduced instruction set computers (RISC), or an array of such RISC's. The one or more processors are operable to execute one or more software products, including computer instructions, to control the operations of the radar system 10.

[0093] Optionally, the transmitter signal processing arrangement 40 is operable to employ chirp modulation to generate a chirped signal, also known as a sweep signal, to circumvent a situation arising in operation that the jamming source 90 present in the region of interest (ROI) 20 becomes aware of a manner of operation of the radar system 10. In one example, a chirp rate is dynamically changed to be different from that of the signals from the jamming source 90, for example by pseudo-randomly varying the chirp rate, for example the chirp rate is varied pursuant to a pre-defined pattern, like a linear chirp or an exponential chirp; such an approach is advantageous as it makes it very difficult for the jamming source 90 to interfere, for any extensive period of time, with operation of the radar system 10. More specifically, in frequency modulated continuous wave (FMCW) radar systems, there is typically employed chirp bandwidths of several 100 MHz, that are then, upon being emitted as the electromagnetic radar radiation 35 to the region of interest (ROI) 20 and then reflected therefrom as the reflected electromagnetic radar radiation 45, de-chirped with reference to a given signal employed to generate the electromagnetic radar radiation 35 down to baseband signals for subsequent processing in the radar system 10, for example for time-gating and/or correlation algorithms. Such chirp bandwidths of several 100 MHz are therefore, optionally, employed in operation of the radar system 10. Optionally, the transmitter signal processing arrangement 40 is operable to modulate the signals to generate the chirp signals in a range of 100 MHz to 500 MHz, and more optionally substantially 300 MHz. Yet alternatively, the radar system 10 is operable to employ narrower chirp bandwidths of less than 100 MHz, but dynamically vary a centre frequency of the chirps, for example in a pre-determined manner, in a repetitive manner, of in a frequency-swept manner as a function of time. Yet alternatively, the radar system 10 is operable to switch between employing wide-bandwidth chirps and narrow-bandwidth chirps, for example in chirping manner as aforementioned, to confuse interfering sources that are potentially present in operation in the region of interest (ROI) 20. Yet alternatively, a manner of chirping employed in the radar system 10 is adaptively changed as a function of being able to address interfering from the region of interest (ROI) 20, as a result of testing various chirping strategies and determining which of the chirping strategies provides a best suppression of interference from the region of interest (ROI) 20 when the radar system 10 is in operation.

[0094] Optionally, the transmitter signal processing arrangement 40 is operable to employ frequency hopping for the radar system 10 to avoid jamming at a specific frequency, such as the frequency corresponding to the jamming source 90. Optionally, the transmitter signal processing arrangement 40 is operable to employ temporally pseudo-random frequency hopping in operation. For example, the transmitter signal processing arrangement 40 is operable to employ a sequence of operating frequencies that are repeated after predefined intervals; such a repeated form of signal is beneficially correlated with the reflected electromagnetic radar radiation 45 from the region of interest (ROI) 20 during detection, to achieve an improved reliability of detection of one or more objects 70 in the region of interest (ROI) 20. The frequency steps employed between the individual continuous wave (CW) frequencies corresponds to a baseband bandwidth of the receiving antenna arrangement 50 and the receiver signal processing arrangement 60 of the radar system 10 for processing the received signal corresponding to the reflected electromagnetic radar radiation 45 from the region of interest (ROI) 20. Optionally, in the radar system 10, the transmitter signal processing arrangement 40 is operable to emit the electromagnetic radar radiation 35 as a plurality of continuous waves (CW) covering an instantaneous bandwidth of the radar waveform employed; such that it is feasible to process the received signal corresponding to the reflected electromagnetic radar radiation 45 to determine a spatial location, frequency range and emitting power of jamming source 90 present in operation within the region of interest (ROI) 20.

[0095] Referring to FIG. 2, there is shown a flow chart of steps of a method 100 of operating the radar system 10 for monitoring the region of interest (ROI) 20. The method 100 includes arranging for the radar system 10 to include the auxiliary channel antenna arrangement 80 for receiving signals from the region of interest (ROI) 20, wherein the auxiliary channel antenna arrangement 80 has a sensing characteristic that is mutually different to that of the receiving antenna arrangement 50. The method 100 further includes operating the receiver signal processing arrangement 60 to process the received signals from the receiving antenna arrangement 50 and from the auxiliary channel antenna arrangement 80, and to discriminate therefrom one or more signals corresponding to the jamming source 90 in or near the region of interest (ROI) 20 from the received signals from the receiving antenna arrangement 50. As described in the foregoing, the method 100 optionally includes employing chirped signals for use when radar-interrogating the region of interest (ROI) 20. Moreover, as described in the foregoing, the method 100 optionally includes employing varying angular orientation of the receiving antenna arrangement 50 relative to the receiving antenna arrangement 50 for assisting the radar system 10 to detect and suppress interfering radiation arising in operation from the region of interest (ROI) 20.

[0096] The radar system 10 is capable of being used in many fields of application, for example: [0097] (i) for monitoring safety-critical areas, for example railway level-crossings; [0098] (ii) for intruder alarm systems, for example for detecting unauthorized personnel; [0099] (iii) for obstacle detection in automated agricultural equipment, for example automated combine harvesters, ploughing equipment, automated fruit picking apparatus; [0100] (iv) for use on harbour (harbor; US English) facilities, for example for guiding automated equipment for handling ship containers; [0101] (v) for on-vehicle radar systems, for example for automatic vehicle braking systems and/or automatic vehicle steering systems; [0102] (vi) for airborne projectile guidance, for example high-velocity guided mortars; and so forth.

[0103] Modifications to embodiments of the present disclosure described in the foregoing are possible without departing from the scope of the invention as defined by the accompanying claims. Expressions such as including, comprising, incorporating, consisting of, have, is used to describe and claim the present disclosure are intended to be construed in a non-exclusive manner, namely allowing for items, components or elements not explicitly described also to be present. Reference to the singular is also to be construed to relate to the plural. Numerals included within parentheses in the accompanying claims are intended to assist understanding of the claims and should not be construed in any way to limit subject matter claimed by these claims.