An airborne weather radar system based on a one-dimensional active phased array Doppler system

Abstract

The application discloses a kind of based on one-dimensional active phased array Doppler system's airborne weather radar system, it is related to airborne weather radar technical field, including terminal subsystem, signal processing module, digital intermediate frequency module, chip active module, integrated split waveguide antenna and correction module;Wherein radar is using one-dimensional active phased array Doppler system, integrated split waveguide antenna's airborne weather radar, transmitting signal, local signal and phase reference signal are all by a main oscillator source synchronous generation, beam flexible and changeable, can improve space-time resolution high;Contour correction integrated split waveguide antenna design and chip active module integrated design are simultaneously used, realize the miniaturization of active antenna array front end, light weight, solve airborne limited space miniaturization, light weight design requirement;Solve the problem that existing ground-based radar is not enough mobile flexible, air-based radar detection distance resolution is low, airborne space size is limited.

Description

Technical Field

[0001] This invention relates to the field of airborne weather radar technology, specifically an airborne weather radar system based on a one-dimensional active phased array Doppler system. Background Technology

[0002] For rapidly changing, small- and medium-scale weather processes that are prone to causing severe weather, such as hail clouds, typhoons, and torrential rains, existing ground-based detection technologies are insufficient to achieve high spatiotemporal resolution detection capabilities, failing to meet the operational requirements for detecting the three-dimensional fine structure and evolution of weather processes. Advanced detection methods are also lacking for cloud observation, making it difficult to obtain accurate information on cloud structure and state.

[0003] Current detection methods, from ground-based to airborne to space-based, each have their own characteristics. Ground-based radar systems have high network density and can monitor local precipitation, but they lack mobility and flexibility. Space-based systems have a large observation range and can monitor weather phenomena over a wide area, but due to their great distance from Earth, the range resolution of the observed data is low. Airborne observation platforms can be divided into stationary and mobile types. Mobile platforms can quickly reach designated airspace for mobile observation, compensating for the shortcomings of ground-based and space-based observations. Based on these shortcomings, this invention proposes an airborne weather radar system based on a one-dimensional active phased array Doppler system. Summary of the Invention

[0004] This invention aims to solve at least one of the technical problems existing in the prior art. To this end, this invention proposes an airborne weather radar system based on a one-dimensional active phased array Doppler system.

[0005] To achieve the above objectives, according to an embodiment of the first aspect of the present invention, an airborne weather radar system based on a one-dimensional active phased array Doppler system is proposed, comprising a terminal subsystem, a signal processing module, a digital intermediate frequency module, a chip active module, an integrated slotted waveguide antenna, and a correction module;

[0006] The terminal subsystem is connected to the signal processing module for beam control, monitoring, and echo data processing, and sends the required operating mode to the signal processing module. Upon receiving the operating mode, the signal processing module sends control signals and operating parameters to each subsystem. It outputs an intermediate frequency signal with the required frequency and phase through a digital intermediate frequency module, then up-converts the signal via a transceiver module to send an excitation signal to a chip active module. The signal is then amplified by the T / R component in the chip active module and output to the corresponding integrated slotted waveguide antenna. The antenna then radiates the signal to synthesize the required transmit beam in space.

[0007] The integrated slotted waveguide antenna receives the echo signal and sends it to the chip active module for filtering, amplification, and synthesis before outputting it to the transceiver module. After down-conversion and digital intermediate frequency processing, the transceiver module transmits the I / Q signal to the signal processing module via optical fiber. The signal processing module performs pulse compression and Doppler processing on the echo signal to obtain information data reflecting meteorological targets.

[0008] The calibration module is used to generate test signals to perform amplitude and phase detection, receiver channel amplification characteristic detection, and calibration on each transceiver module.

[0009] Furthermore, the specific testing process for the calibration module is as follows:

[0010] The digital intermediate frequency module generates an analog target signal, which is coupled to the receiving channel of the 32-channel TR component via a calibration network. After synthesis, the signal is sent back to the digital intermediate frequency module to generate I / Q signals, which are then sent to the signal processing module for processing to test and verify the basic functions of the system channels.

[0011] Furthermore, the servo actuator is controlled by a signal processing module for scanning; the servo actuator consists of a servo control board, a driver, an encoder, and an electric actuator, achieving a scanning range of -30° to 30° in the pitch direction; the specific working steps are as follows:

[0012] According to the monitoring instructions, the servo control board is controlled to perform scanning motions at different speeds, while providing the antenna's elevation angle information. The servo control board receives the antenna control instructions and the angle code output by the encoder. After decoding and software processing, it outputs the level signal controlling the rotation direction of the electric actuator and the speed signal controlling the electric actuator to the servo driver, driving the motor to rotate.

[0013] Furthermore, the signal processing module adopts a general-purpose platform with a DSP+FPGA combined architecture, including two BWDSP100 chips and one EP2SGX9 chip; the two BWDSP100 chips are interconnected through multiple link ports, and each link port achieves a unidirectional data transmission speed of 300MB / s; the signal processing module communicates with other systems through four fiber optic interfaces, a network interface, and a serial port, and receives I / Q signals through a high-speed fiber optic interface, performing pulse compression processing, filtering processing, and meteorological element estimation on the I / Q signals.

[0014] Furthermore, the radar is a fully coherent one-dimensional active phased array Doppler weather radar, in which the radar's transmitted signal, local oscillator signal, and coherent reference signal are all synchronously generated by a single master source.

[0015] Furthermore, the integrated slotted waveguide antenna includes a slotted antenna surface, a correction network, and an radome; the slotted antenna surface is composed of 32 slotted waveguides arranged in a row, with the longer ones located in the middle of the antenna and the rest arranged on both sides of the antenna surface; the correction network is located behind the antenna and installed at the center of the 32 slotted waveguides; the radome is designed according to the external dimensions of the antenna surface, and after installation, the radome forms an integral part of the antenna; the integrated slotted waveguide antenna is used to directionally radiate the high-power pulse signal output by the radar transceiver assembly into space; during the transmission pulse interval, the echo signal enters the receiving branch of the transceiver assembly through the antenna.

[0016] Furthermore, the chip active module integrates eight four-channel chip T / R components and a comprehensive feed network; during reception, the chip active module receives the weak echo signal output by the antenna, and after filtering, amplification and synthesis, it becomes a single received radio frequency signal; during transmission, the excitation signal is amplified and phase-shifted by the chip active module to generate 32 signals greater than 20W, which are then radiated out by the antenna to form a beam.

[0017] Furthermore, the transceiver module includes a switching amplification and attenuation component, a frequency conversion channel, a three-pulse intermediate frequency digital receiver, and a frequency source, used to provide radio frequency transmission signals for the radar; specifically:

[0018] The weak echo signal is amplified and frequency-converted to obtain an intermediate frequency signal. Then, the I / Q signal of the echo signal is extracted through coherent demodulation. The I / Q signal is provided to the signal processing module for Doppler processing, and the excitation signal, the synchronization clock signal of the whole machine, and the calibration signal of the whole machine are output to realize the characteristic detection and calibration of key parameters of the radar system.

[0019] Compared with the prior art, the beneficial effects of the present invention are:

[0020] In this invention, the radar adopts a one-dimensional phased array Doppler system instead of traditional mechanical scanning. This allows for flexible beam variation, high scanning speed, and multiple operating modes, resulting in high spatiotemporal resolution. The radar employs an integrated profile-corrected slotted waveguide antenna design, meeting the design parameters of an airborne weather radar system and satisfying the needs for more refined detection of rapidly changing small-to-medium-scale weather processes, ocean convection detection, and polar and upper atmospheric chemical detection. The chip-type active module integrates chip-type T / R components and a comprehensive feed network, achieving miniaturization and weight reduction of the active antenna array front end, addressing the miniaturization and weight reduction design requirements within limited airborne space. The high integration performance of the one-dimensional phased array better adapts to airborne platforms, and its beam agility meets the needs of rapid and precise observation, solving the problems of insufficient mobility and flexibility of existing ground-based radars, low detection range and resolution of airborne radars, and limited airborne space. Attached Figure Description

[0021] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0022] Figure 1 This is a system block diagram of an airborne weather radar system based on a one-dimensional active phased array Doppler system according to the present invention.

[0023] Figure 2 This is the circuit schematic diagram of the present invention.

[0024] Figure 3 This is a schematic diagram of the integrated slot waveguide antenna in this invention.

[0025] Figure 4 This is a schematic diagram of the chip-type active module in this invention. Detailed Implementation

[0026] The technical solution of the present invention will be clearly and completely described below with reference to the embodiments. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0027] like Figure 1 As shown, an airborne weather radar system based on a one-dimensional active phased array Doppler system includes a terminal subsystem, a signal processing module, a transceiver module, a main oscillator, a digital intermediate frequency module, a chip active module, an integrated slotted waveguide antenna, and a correction module.

[0028] The radar is a fully coherent one-dimensional active phased array Doppler weather radar, in which the radar's transmitted signal, local oscillator signal, and coherent reference signal are all synchronously generated by a highly stable and high-purity master oscillator, and they maintain a strict and fixed phase relationship.

[0029] Radar detects, analyzes, and identifies precipitation targets by emitting high-power microwave pulse signals and utilizing the backscattering from meteorological targets such as clouds and rain.

[0030] During operation, the terminal subsystem sends the required operating mode to the signal processing module. Upon receiving the operating mode, the signal processing module sends control signals and operating parameters to each subsystem. The digital intermediate frequency module outputs an intermediate frequency signal with the required frequency and phase, which is then up-converted by the transceiver module and sent to the chip active module. After being amplified by the T / R component in the chip active module, the signal is output to the corresponding antenna element, i.e., the integrated slotted waveguide antenna. Through antenna radiation, the radiated power of each element is combined in space to form the required transmit beam.

[0031] The antenna array element receives the echo signal and sends it to the chip active module. After filtering, amplification and synthesis, the signal is output to the transceiver module. After down-conversion and digital intermediate frequency processing, the I / Q signal is transmitted to the signal processing module through optical fiber. The signal processing module performs pulse compression and Doppler processing on the echo signal to obtain information data reflecting the meteorological target.

[0032] The calibration module generates test signals to perform amplitude and phase detection, receiver channel amplification characteristic detection, and calibration on each transceiver module; specifically:

[0033] The digital intermediate frequency module generates an analog target signal, which is coupled to the receiving channel of the 32-channel TR component through a correction network. After being synthesized, the signal is sent back to the digital intermediate frequency module to generate I / Q signals, which are then sent to the signal processing module for processing to test and verify the basic functions of the system channels.

[0034] The servo push rod is controlled by a signal processing module for scanning. The servo push rod consists of a servo control board, a driver, an encoder, and an electric push rod, achieving a scanning range of -30° to 30° in the pitch direction.

[0035] This servo actuator adopts an advanced, mature, and stable high-precision DC servo system. According to the requirements of the monitoring command, the servo control board performs scanning motion at different speeds, while providing the antenna's elevation angle information. The servo control board receives the antenna control command and the angle code output by the encoder. After decoding and software processing, the above information outputs the level signal controlling the rotation direction of the electric actuator and the speed signal controlling the electric actuator to the servo driver, driving the motor to rotate.

[0036] The signal processing module adopts a general-purpose platform with a DSP+FPGA combined architecture. This module architecture mainly consists of two BWDSP100 chips and one Altera EP2SGX90 chip. It also utilizes RAM, FLASH, and DDR2 devices to store system data and programs. For external communication, it communicates with other systems through four fiber optic interfaces, a network interface, and a serial port. Internally, one FPGA communicates bidirectionally with the two DSPs via a link port. The two BWDSP100 chips are interconnected using multiple link ports, each with a unidirectional data transfer speed of up to 300MB / s (75M*32bit / s). Furthermore, to meet the storage requirements of large data volumes and to enable multi-processor coupling, each BWDSP100 chip includes 1Gb of external DDR2 memory. Through fly-through transfer, different processors can indirectly share the DDR2 external memory. The signal processing module receives I / Q signals through a high-speed fiber optic interface, performs pulse compression processing, filtering processing, and meteorological element estimation on them. The radar adopts a three-pulse working mode with two blind-filling pulses. After processing the echoes of the three pulses separately, the data is spliced ​​and processed before the meteorological element data is output.

[0037] like Figure 2 As shown, the radar adopts a one-dimensional phased array Doppler system instead of traditional mechanical scanning. The beam is flexible and variable, the scanning speed is fast, the system can realize multiple working modes, and the spatiotemporal resolution is high.

[0038] like Figures 3 to 4 As shown, the radar adopts an integrated slotted waveguide antenna design with contour correction to meet the design parameters of the airborne weather radar system; the chip active module integrates chip T / R components and integrated feed network, realizing the miniaturization and weight reduction of the front end of the active antenna array, and solving the miniaturization and weight reduction design requirements of airborne limited space;

[0039] The integrated slotted waveguide antenna consists of a slotted antenna surface (integrated antenna frame), a correction network, and a radome. The slotted antenna surface is composed of 32 slotted waveguides arranged in a row, with the longer ones located in the center and the rest on either side. The correction network is located behind the antenna and installed at the center opening of the 32 slotted waveguides. The radome is designed according to the external dimensions of the antenna surface and forms an integral part of the antenna after installation. The antenna employs a contour-corrected design to address the miniaturization and lightweight design requirements within limited airborne space, meeting the design parameters of the airborne weather radar system. The antenna's dimensions are 560mm × 600mm × 60mm (width × height × thickness), and it weighs approximately 8.3kg. The antenna primarily directs the high-power pulse signal output from the radar transceiver assembly into space; during the transmission pulse interval, the echo signal enters the receiving branch of the transceiver assembly through the antenna.

[0040] The chip active module adopts a highly integrated general building block (CBB) design, integrating eight four-channel chip T / R components and a comprehensive feed network (power divider and combiner network, power distribution network and final stage beam control), realizing the miniaturization and weight reduction of the front end of the active antenna array. During reception, the chip active module receives the weak echo signal output by the receiving antenna, and after filtering, amplification and combining, it becomes a single receiving RF signal. During transmission, the excitation signal is amplified and phase-shifted by the chip active module to generate 32 signals greater than 20W, which are then radiated out by the antenna to form a beam.

[0041] The transceiver module consists of a switching amplification and attenuation component, a frequency conversion channel, a three-pulse intermediate frequency digital receiver, and a frequency source. Its main function is to provide the radar with high-power, fully coherent, and high-quality radio frequency transmission signals; to amplify and convert weak echo signals to intermediate frequency signals through high sensitivity, and then extract the I and Q information of the echo signals through coherent demodulation, providing this information to the signal processing subsystem for Doppler processing; it generates the transmission excitation signal and the system's synchronization clock signal, and also provides the system's calibration signal for measuring and calibrating some key parameters of the radar system. The transmission and reception frequency range of this system is specified as 9320–9420 MHz, and the system design requires switching between 11 operating frequency points; the frequencies of the three-pulse signals are, in order: short pulse 125 MHz, medium pulse 153.5–156.5 MHz, and long pulse 139–141 MHz. The ADC chip used is the GK3128, a domestically produced off-the-shelf ADC chip with reliable and stable performance.

[0042] In the description of this specification, references to terms such as "an embodiment," "example," "specific example," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the invention. In this specification, illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0043] The preferred embodiments of the present invention disclosed above are merely illustrative of the invention. These preferred embodiments do not exhaustively describe all details, nor do they limit the invention to any specific implementation. Clearly, many modifications and variations can be made based on the content of this specification. This specification selects and specifically describes these embodiments to better explain the principles and practical applications of the invention, thereby enabling those skilled in the art to better understand and utilize the invention. The invention is limited only by the claims and their full scope and equivalents.

Claims

1. An airborne weather radar system based on a one-dimensional active phased array Doppler system, characterized in that, It includes a terminal subsystem, a signal processing module, a transceiver module, a digital intermediate frequency module, a chip active module, an integrated slotted waveguide antenna, and a correction module; The terminal subsystem is connected to the signal processing module for beam control, monitoring, and echo data processing, and sends the required operating mode to the signal processing module. Upon receiving the operating mode, the signal processing module sends control signals and operating parameters to each subsystem. It outputs an intermediate frequency signal with the required frequency and phase through a digital intermediate frequency module, then up-converts the signal via a transceiver module to send an excitation signal to a chip active module. The signal is then amplified by the T / R component in the chip active module and output to the corresponding integrated slotted waveguide antenna. The antenna then radiates the signal to synthesize the required transmit beam in space. The integrated slotted waveguide antenna includes a slotted antenna surface, a correction network, and a radome. The slotted antenna surface is composed of 32 slotted waveguides arranged in a row, with the longer ones located in the middle and the rest arranged on both sides of the antenna surface. The correction network is located behind the antenna and installed at the center of the 32 slotted waveguides. The radome is designed according to the external dimensions of the antenna surface and forms an integral part of the antenna after installation. The integrated slotted waveguide antenna is used to directionally radiate the high-power pulse signal output by the radar transceiver assembly into space. During the transmission pulse interval, the echo signal enters the receiving branch of the transceiver assembly through the antenna. The integrated slotted waveguide antenna receives the echo signal and sends it to the chip active module for filtering, amplification, and synthesis before outputting it to the transceiver module. After down-conversion and digital intermediate frequency processing, the transceiver module transmits the I / Q signal to the signal processing module via optical fiber. The signal processing module performs pulse compression and Doppler processing on the echo signal to obtain information data reflecting meteorological targets. The chip active module integrates eight four-channel chip T / R components and a comprehensive feed network. During reception, the chip active module receives the weak echo signal output by the antenna, and after filtering, amplification and synthesis, it becomes a single received radio frequency signal. During transmission, the excitation signal is amplified and phase-shifted by the chip active module to generate 32 signals greater than 20W, which are then radiated out by the antenna to form a beam. The calibration module generates test signals to perform amplitude and phase detection, receiver channel amplification characteristic detection, and calibration on each transceiver module. The specific testing process of the calibration module is as follows: The digital intermediate frequency module generates an analog target signal, which is coupled to the receiving channel of the 32-channel TR component through a correction network. After being synthesized, the signal is sent back to the digital intermediate frequency module to generate I / Q signals, which are then sent to the signal processing module for processing to test and verify the basic functions of the system channels. Among them, the radar is a fully coherent one-dimensional active phased array Doppler weather radar, in which the radar's transmitted signal, local oscillator signal and coherent reference signal are all synchronously generated by a main oscillator source; The transceiver module includes a switching amplification and attenuation component, a frequency conversion channel, a three-pulse intermediate frequency digital receiver, and a frequency source, used to provide radio frequency transmission signals for the radar; specifically: The weak echo signal is amplified and frequency-converted to obtain an intermediate frequency signal. Then, the I / Q signal of the echo signal is extracted through coherent demodulation. The I / Q signal is provided to the signal processing module for Doppler processing, and the excitation signal, the synchronization clock signal of the whole machine, and the calibration signal of the whole machine are output to realize the characteristic detection and calibration of key parameters of the radar system.

2. The airborne weather radar system based on a one-dimensional active phased array Doppler system according to claim 1, characterized in that, in, The servo actuator is controlled by a signal processing module for scanning; the servo actuator consists of a servo control board, a driver, an encoder, and an electric actuator, achieving a scanning range of -30° to 30° in the pitch direction; the specific working steps are as follows: According to the monitoring instructions, the servo control board is controlled to perform scanning motions at different speeds, while providing the antenna's elevation angle information. The servo control board receives the antenna control instructions and the angle code output by the encoder. After decoding and software processing, it outputs the level signal controlling the rotation direction of the electric actuator and the speed signal controlling the electric actuator to the servo driver, driving the motor to rotate.

3. An airborne weather radar system based on a one-dimensional active phased array Doppler system according to claim 1, characterized in that, The signal processing module adopts a general-purpose platform with a DSP+FPGA combined architecture, including two BWDSP100 chips and one EP2SGX9 chip; the two BWDSP100 chips are interconnected by multiple link ports, and the unidirectional data transmission speed of each link port reaches 300MB / s. The signal processing module communicates with other systems through four fiber optic interfaces, a network interface, and a serial port. It receives I / Q signals through a high-speed fiber optic interface and performs pulse compression processing, filtering, and meteorological element estimation on the I / Q signals.

Images