阅读说明：本技术 脉内空域扫描雷达系统及其接收和处理方法 (Intra-pulse space scanning radar system and receiving and processing method thereof ) 是由 郭汝江 刘会杰 赵灵峰 倪迎红 于 2020-11-19 设计创作，主要内容包括：本发明提供了一种脉内空域扫描雷达系统及其接收和处理方法,包括：脉内扫描发射模块,被配置为通过多样化阵元发射信号,进行阵列天线的脉内扫描发射；回波信号接收模块,被配置为通过多波束接收进行覆盖空域内目标回波信号的接收；以及回波信号处理模块,被配置为通过多脉冲相参积累检测,对目标回波信号进行处理。(The invention provides an intra-pulse area scanning radar system and a receiving and processing method thereof, wherein the receiving and processing method comprises the following steps: the intra-pulse scanning and transmitting module is configured to transmit signals through the diversified array elements and perform intra-pulse scanning and transmitting of the array antenna; the echo signal receiving module is configured to receive a target echo signal in a coverage airspace through multi-beam reception; and an echo signal processing module configured to process the target echo signal through multi-pulse coherent accumulation detection.)

1. An intravascular area scanning radar system, comprising:

the intra-pulse scanning and transmitting module is configured to transmit signals through the diversified array elements and perform intra-pulse scanning and transmitting of the array antenna;

the echo signal receiving module is configured to receive a target echo signal in a coverage airspace through multi-beam reception; and

and the echo signal processing module is configured to process the target echo signal through multi-pulse coherent accumulation detection.

2. The intra-pulse area scanning radar system as claimed in claim 1, wherein in said intra-pulse scanning emission module, N antenna elements are arranged in a one-dimensional linear uniform array, and the emission signal of each element is:

s_k(t)＝w_k(t)exp{jφ_k(t)}，

where k is the array element number, w_k(t) is the signal amplitude, phi_kAnd (t) is the signal phase.

3. The endovenous domain scanning radar system as in claim 2 wherein the signal phase is_k(t) has the form:

φ_k(t)＝f(t)+g_k(t)，

wherein f (t) is 2 pi f₀t is the carrier frequency f₀The resulting phase term, f (t), contains the transmit signal waveform.

4. An airborne area scanning radar system as claimed in claim 3 wherein, when transmitting a chirp signal,

where B is the transmit signal bandwidth, T is the transmit signal time width, g_k(t) phase term due to additional signal:

wherein d is the array element spacing, λ₀＝c/f₀Is the signal wavelength, c is the speed of light, θ_D(t) is the main lobe pointing direction of the transmitted beam within the time of the transmitted pulse, theta_DAnd (t) setting according to a desired main lobe directional scanning mode of the transmitting beam.

5. The endovenular area scanning radar system of claim 4 wherein when a transmit beam mainlobe pointing is desired to scan linearly from-45 degrees to +45 degrees within a transmit pulse time, the transmit beam mainlobe pointing within the transmit pulse time is:

6. a receiving and processing method of the intra-vein area scanning radar system according to claim 1, comprising:

the received signals of each array element are shunted to a plurality of simultaneous multi-beam receiving channels, and the number of the multi-beam receiving channels depends on the beam width and the scanning airspace range of a single beam;

in different multi-beam receiving channels, the received signals of each array element are weighted and accumulated by different phases so as to realize the matched receiving in a certain beam direction;

mixing the received signal of each array element with different center frequencies to form a baseband signal;

processing the baseband signal by adopting matched filtering to form a pulse echo signal, and compressing the pulse echo signal to improve the distance resolution and the signal intensity of the pulse echo signal;

performing range-Doppler processing on the echo signals of the plurality of pulses, and enhancing the echo signals of the pulses again in a Doppler domain;

carrying out target detection in a range-Doppler domain by adopting a two-dimensional CFAR method;

and performing parameter estimation on the detected target according to the target detection result, and giving estimation results of the angle, the distance and the radial speed of the target.

7. A method for receiving and processing an intra-vascular area-scanning radar system as claimed in claim 6, further comprising:

the waveform generator generates a transmitting signal f (t) which is shunted to each antenna array element channel, and each channel adds a frequency offset g to the transmitting signal f (t) through the signal control subsystem_kAnd (t) transmitting through each antenna element.

8. The method for receiving and processing by an airborne spatial scanning radar system of claim 6, wherein the plurality of receive beams overlap at-3 dB of maximum amplitude of the beam, the beam covering the spatial scanning range of the transmit beam.

9. A receiving and processing method for an intra-vascular area-scanning radar system as claimed in claim 6, wherein the angle of the target is 10 degrees, the distance is 10km, and the radial velocity is-24 m/s.

Technical Field

The invention relates to the technical field of radars, in particular to an intra-pulse area scanning radar system and a receiving and processing method thereof.

Background

The spatial scanning mode of conventional radar may be referred to as inter-pulse scanning. In order to detect a target in a large spatial range, a conventional radar operates such that a beam of the radar is scanned in a spatial domain. To complete a spatial scan, the radar needs to transmit at least one pulse in each direction until all spatial regions are covered. Since the spatial scanning is realized by transmitting radar pulses in a plurality of different directions, the spatial scanning mode can be called inter-pulse scanning, namely the spatial scanning is completed between pulses, and the main lobe direction of a beam in a single transmission pulse time is fixed in a certain direction.

The inter-pulse scanning radar needs to transmit at least one pulse in each direction until the scanning of a coverage airspace is finished, the scanning energy consumption is large, and the scanning method is complex; in addition, because the energy of a single transmitting pulse is concentrated in a narrow space domain, the transmitting signal of the inter-pulse scanning radar is easy to be intercepted by an interference machine, and the anti-interception performance is poor.

Disclosure of Invention

The invention aims to provide an intra-pulse area scanning radar system and a receiving and processing method thereof, so as to solve the problem that the conventional inter-pulse scanning radar scanning method is complex.

To solve the above technical problem, the present invention provides an intravascular area scanning radar system, including:

the intra-pulse scanning and transmitting module is configured to transmit signals through the diversified array elements and perform intra-pulse scanning and transmitting of the array antenna;

the echo signal receiving module is configured to receive a target echo signal in a coverage airspace through multi-beam reception; and

and the echo signal processing module is configured to process the target echo signal through multi-pulse coherent accumulation detection.

Optionally, in the intra-pulse area scanning radar system, in the intra-pulse scanning transmitting module, the N antenna elements are arranged according to a one-dimensional linear uniform array, and a transmission signal of each antenna element is:

s_k(t)＝w_k(t)exp{jφ_k(t)}，

where k is the array element number, w_k(t) is the signal amplitude, phi_kAnd (t) is the signal phase.

Optionally, in the intra-pulse space scanning radar system, the signal phase phi_k(t) has the form:

φ_k(t)＝f(t)+g_k(t)，

wherein f (t) is 2 pi f₀t is the carrier frequency f₀The resulting phase term, f (t), contains the transmit signal waveform.

Optionally, in the intra-pulse area scanning radar system, when transmitting a chirp signal,

where B is the transmit signal bandwidth, T is the transmit signal time width, g_k(t) phase term due to additional signal:

wherein d is the array element spacing, λ₀＝c/f₀Is the signal wavelength, c is the speed of light, θ_D(t) is the main lobe pointing direction of the transmitted beam within the time of the transmitted pulse, theta_DAnd (t) setting according to a desired main lobe directional scanning mode of the transmitting beam.

Optionally, in the intra-pulse area scanning radar system, when a transmit beam main lobe direction is expected to be linearly scanned from-45 degrees to +45 degrees within a transmit pulse time, the transmit beam main lobe direction within the transmit pulse time is:

the invention also provides a receiving and processing method of the intravascular area scanning radar system, which comprises the following steps:

the received signals of each array element are shunted to a plurality of simultaneous multi-beam receiving channels, and the number of the multi-beam receiving channels depends on the beam width and the scanning airspace range of a single beam;

in different multi-beam receiving channels, the received signals of each array element are weighted and accumulated by different phases so as to realize the matched receiving in a certain beam direction;

mixing the received signal of each array element with different center frequencies to form a baseband signal;

processing the baseband signal by adopting matched filtering to form a pulse echo signal, and compressing the pulse echo signal to improve the distance resolution and the signal intensity of the pulse echo signal;

performing range-Doppler processing on the echo signals of the plurality of pulses, and enhancing the echo signals of the pulses again in a Doppler domain;

carrying out target detection in a range-Doppler domain by adopting a two-dimensional CFAR method;

and performing parameter estimation on the detected target according to the target detection result, and giving estimation results of the angle, the distance and the radial speed of the target.

Optionally, in the receiving and processing method of the intra-pulse area scanning radar system, the method further includes:

the waveform generator generates a transmitting signal f (t) which is shunted to each antenna array element channel, and each channel adds a frequency offset g to the transmitting signal f (t) through the signal control subsystem_kAnd (t) transmitting through each antenna element.

Optionally, in the receiving and processing method of the intra-spatial scanning radar system, a plurality of receiving beams overlap at a position of-3 dB of the maximum amplitude of the beam, and the beam covers a spatial scanning range of the transmitting beam.

Optionally, in the receiving and processing method of the intra-vascular area scanning radar system, the angle of the target is 10 degrees, the distance is 10km, and the radial velocity is-24 m/s.

In the intra-pulse scanning radar system and the receiving and processing method thereof provided by the invention, the intra-pulse scanning emission module emits signals through diversified array elements to perform intra-pulse scanning emission of the array antenna, the echo signal receiving module receives target echo signals in a coverage space through multi-beam reception, and the echo signal processing module processes the target echo signals through multi-pulse coherent accumulation detection, so that the intra-pulse scanning radar is a radar which finishes scanning of the coverage space within a single emission pulse. Unlike inter-pulse scanning, which allows the radar to scan a desired spatial range within a single transmit pulse, the beam orientations of the individual transmit pulses may be scanned from one angle to another, such as from-45 degrees to +45 degrees. The intra-pulse scanning radar realizes the detection of the target through multi-pulse coherent accumulation.

The intra-pulse scanning radar can complete the scanning of a coverage airspace in a single emission pulse, and because the energy of the single emission pulse is dispersed to a wider airspace range, the emission signal of the intra-pulse scanning radar has low interception characteristic and is not easy to be intercepted by an interference machine; and the intra-pulse scanning radar realizes intra-pulse scanning emission by setting the emission signal form of each array element of the emission array antenna, so that the intra-pulse scanning radar has compatibility with the phased array radar, and the working mode of the phased array radar can be expanded.

Drawings

Fig. 1 is a schematic block diagram of a transmitter of an intra-pulse scanning radar according to an embodiment of the present invention;

fig. 2 is a transmission beam pattern of an intra-pulse scanning radar according to an embodiment of the present invention;

fig. 3 is a receiving and processing block diagram of an intra-pulse scanning radar according to an embodiment of the present invention;

fig. 4 shows the range-doppler processing results of the intra-pulse scanning radar according to an embodiment of the present invention.

Detailed Description

The present invention provides an intra-pulse area scanning radar system and a receiving and processing method thereof, which are further described in detail with reference to the accompanying drawings and specific embodiments. Advantages and features of the present invention will become apparent from the following description and from the claims. It is to be noted that the drawings are in a very simplified form and are not to precise scale, which is merely for the purpose of facilitating and distinctly claiming the embodiments of the present invention.

Furthermore, features from different embodiments of the invention may be combined with each other, unless otherwise indicated. For example, a feature of the second embodiment may be substituted for a corresponding or functionally equivalent or similar feature of the first embodiment, and the resulting embodiments are likewise within the scope of the disclosure or recitation of the present application.

The core idea of the invention is to provide an intra-pulse area scanning radar system and a receiving and processing method thereof, so as to solve the problem that the existing inter-pulse scanning radar scanning method is complex.

In order to realize the thought, the invention provides an intra-pulse area scanning radar system and a receiving and processing method thereof, wherein the receiving and processing method comprises the following steps: the intra-pulse scanning transmitting module transmits signals through the diversified array elements to carry out intra-pulse scanning transmission of the array antenna; the echo signal receiving module receives target echo signals in a coverage airspace through multi-beam receiving; and the echo signal processing module processes the target echo signal through multi-pulse coherent accumulation detection.

As known in the art, the main beam lobe of the transmitting antenna pattern of a conventional radar is fixedly directed, and the scanning of the coverage space is accomplished between pulses by adjusting the main beam lobe direction. The invention provides an intra-pulse scanning radar which can carry out coverage airspace scanning in a single transmitting pulse, and the intra-pulse scanning mode provided by the invention can be flexibly adjusted according to the requirement.

In an embodiment of the present invention, N antenna elements are arranged in a one-dimensional linear uniform array (a two-dimensional array of antennas can be extended according to the one-dimensional arrangement, which is not described in detail here), and a transmission signal of each antenna element is:

s_k(t)＝w_k(t)exp{jφ_k(t)} (1)

where k is the array element number, w_k(t) is the signal amplitude, phi_k(t) is the signal phase, having the form:

φ_k(t)＝f(t)+g_k(t) (2)

wherein f (t) 2 pi f0_tIs a carrier frequency f₀The resulting phase term, f (t), may comprise the transmit signal waveform, which, when transmitting a chirp signal,

where B is the transmit signal bandwidth, T is the transmit signal time width, g_k(t) phase term due to additional signal:

wherein d is the array element spacing, λ₀＝c/f₀Is the signal wavelength, c is the speed of light, θ_D(t) is the main lobe pointing direction of the transmitted beam within the time of the transmitted pulse, theta_D(t) can be set according to a desired transmission beam mainlobe pointing scan pattern. In one example, when the transmit beam main lobe pointing is desired to scan linearly from-45 degrees to +45 degrees within the transmit pulse time,

the transmitter block diagram is shown in fig. 1. The waveform generator generates a transmitting signal f (t), and the transmitting signal f (t) is divided into antenna array element channels, and each channel adds a frequency offset gk to the transmitting signal f (t) through the signal control subsystem₍t) and finally transmitted out through each antenna element (the amplitude weighting control in the block diagram can be an amplifier, and the antenna side lobe is controlled or azimuth zero setting is realized through the amplitude weighting).

In one embodiment of the present invention, N is 50, f₀＝8GHz，w_k(T) is hamming weight, and T is 100 μ s.

An intra-pulse scanning radar transmit antenna pattern is shown in fig. 2. As can be seen from fig. 2, the main lobe of the beam is directed to sweep from-45 degrees to +45 degrees within the transmit pulse time in a set manner.

A reception and processing block diagram is shown in fig. 3. The steps of receiving and processing are as follows:

the receiving signal of each array element is shunted to a plurality of simultaneous multi-beam receiving channels, and the number of the channels depends on the beam width and the scanning airspace range of a single beam;

in different receiving channels, the received signal of each array element is firstly weighted and accumulated by different phases to form matched receiving on a certain beam direction;

then, mixing the signals with different center frequencies to mix the signals to baseband signals;

then, the received pulse signals are compressed by adopting matched filtering processing, so that the distance resolution and the signal intensity are improved;

then, the echo signals of a plurality of pulses are subjected to range Doppler processing, and the signals are enhanced again in a Doppler domain;

then, target detection is carried out in a range-Doppler domain, and a two-dimensional CFAR method can be adopted;

and finally, performing parameter estimation on the detected target according to the detection result, and giving an angle, distance and speed estimation result of the target.

In one example of the invention, the target angle is 10 degrees, the distance is 10km, and the radial velocity is-24 m/s. The results of matched filtering and range-doppler processing are shown in fig. 4, and the target parameters can be effectively estimated.

The invention provides a radar transmitting and receiving processing method for realizing intra-pulse area scanning. The intra-pulse scanning radar provided by the invention realizes intra-pulse scanning emission of the array antenna through diversified array element emission signals, realizes the reception of target echo signals in a coverage airspace through simultaneous multi-beam reception, and realizes the signal processing of the target echo through multi-pulse coherent accumulation detection.

Specifically, the transmission signal of each array element of the array antenna for intra-pulse scanning transmission is s_k(t)＝w_k(t)exp{jφ_k(t), where k is the array element number,w_k(t) is the signal amplitude, phi_kAnd (t) is the signal phase.

In general, φ_k(t)＝f(t)+g_k(t), wherein f (t) 2 pi f₀t is the carrier frequency f₀The resulting phase term, f (t), may comprise the transmit signal waveform, which, when transmitting a chirp signal,

wherein B is the transmission signal bandwidth, T is the transmission signal time width,

the phase term induced for the additional signal,

wherein d is the array element spacing, λ₀＝c/f₀Is the signal wavelength, c is the speed of light, θ_D(t) is the main lobe pointing direction of the transmitted beam within the time of the transmitted pulse, theta_D(t) can be set according to the expected main lobe direction scanning mode of the transmitting beam, when the main lobe direction of the transmitting beam is expected to be linearly scanned from-45 degrees to +45 degrees in the time of transmitting pulse,

in addition, the receiving of the intra-pulse scanning radar is realized by adopting simultaneous multi-beam receiving, a plurality of receiving beams are overlapped at a position of-3 dB of the maximum amplitude of the beam, and the beam covers the airspace scanning range of the transmitting beam. The signal processing of the intra-pulse scanning radar firstly carries out matched filtering processing, then carries out range-Doppler coherent processing on echo signals of a plurality of pulses, and finally carries out target detection and parameter estimation.

The advantages of the invention include: the intra-pulse scanning radar can complete the scanning of a coverage airspace in a single emission pulse, and because the energy of the single emission pulse is dispersed to a wider airspace range, the emission signal of the intra-pulse scanning radar has low interception characteristic and is not easy to be intercepted by an interference machine; and the intra-pulse scanning radar realizes intra-pulse scanning emission by setting the emission signal form of each array element of the emission array antenna, so that the intra-pulse scanning radar has compatibility with the phased array radar, and the working mode of the phased array radar can be expanded.

In summary, the above embodiments have described in detail different configurations of the airborne area scanning radar system and the receiving and processing method thereof, and it is understood that the present invention includes, but is not limited to, the configurations listed in the above embodiments, and any modifications based on the configurations provided by the above embodiments are within the scope of the present invention. One skilled in the art can take the contents of the above embodiments to take a counter-measure.

The embodiments in the present description are described in a progressive manner, each embodiment focuses on differences from other embodiments, and the same and similar parts among the embodiments are referred to each other. The above description is only for the purpose of describing the preferred embodiments of the present invention, and is not intended to limit the scope of the present invention, and any variations and modifications made by those skilled in the art based on the above disclosure are within the scope of the appended claims.