Multifunctional Device for Light and Small Satellite SAR Payload

Abstract

The present invention provides a multi-functional device for a lightweight small satellite SAR payload, which relates to the field of spaceborne radar technology. Each module of the multi-functional device for the lightweight small satellite SAR payload of the present invention is connected through a high-speed serial connection method, so as to realize the three major functions of data acquisition, data storage and data processing with one device, improve the integration degree of the multi-functional device for the SAR payload, reduce the cost of the SAR payload, and reduce the volume of the SAR payload, and can meet the requirements of low cost, high integration and high reliability of the lightweight small satellite.

Description

Technical Field

[0001] The present invention relates to the technical field of spaceborne radar, and particularly to a multi-functional device for a light and small satellite SAR payload. Background Art

[0002] Light and small satellites are small in size, and the SAR (Synthetic Aperture Radar) payload is installed inside the satellite. Therefore, a SAR payload with a small size and high integration is required.

[0003] The existing central electronic devices of the SAR payload are numerous, and there are many cables interconnected between them, which are difficult to meet the high integration requirements of light and small commercial satellites. That is, the existing SAR payload has the technical problem of low integration. Summary of the Invention

[0004] (I) Technical Problems to be Solved

[0005] In view of the deficiencies of the prior art, the present invention provides a multi-functional device for a light and small commercial satellite SAR payload, which solves the technical problem of low integration of the existing SAR payload.

[0006] (II) Technical Solutions

[0007] To achieve the above object, the present invention is realized through the following technical solutions:

[0008] In a first aspect, the present invention provides a multi-functional device for a light and small satellite SAR payload, including: a data acquisition module, a data processing module, and a data storage module, and each module is connected by a serial connection method;

[0009] Among them, the data acquisition module is used to transmit a chirp signal, sample the echo signal to obtain the original echo data; perform digital decimation, digital filtering, and compression on the original echo data, and send the compressed original echo data to the data storage module;

[0010] The data processing module is used to process the original echo data stored in the data storage module, and send the processed echo data to the data storage module;

[0011] The data storage module sends the original echo data and the processed echo data to the data transmission device according to an external control instruction.

[0012] Preferably, the external control instruction is sent by a master control device, where

[0013] the master control device communicates with the multi-functional device for the light and small satellite SAR payload through LVDS communication.

[0014] Preferably, the step of sending the original echo data and the processed echo data to the data transmission device includes:

[0015] Sending the original echo data and the processed echo data to the data transmission device through wireless communication or LVDS communication.

[0016] Preferably, the multi-functional device for a light and small satellite SAR payload further includes: a power supply module;

[0017] The power supply module includes a DC / DC power supply unit and an LDO conversion unit. The external power supply is converted to 3.3V through the DC / DC power supply unit and then converted through the LDO conversion unit to supply power to the chips in the multi-functional device for the light and small satellite SAR payload.

[0018] Preferably, the data acquisition module includes an FPGA chip, two AD circuits, and two DA circuits;

[0019] The FPGA chip is connected to the two AD circuits through an LVDS bus to realize the sampling of the echo signal;

[0020] The FPGA chip is connected to the two DA circuits through an LVDS bus to generate intermediate frequency signals.

[0021] Preferably, the data storage module includes an FPGA chip and an mSATA disk, wherein the FPGA chip shares one chip with the data acquisition module.

[0022] Preferably, the data processing module includes a DSP chip and four DDR3 memory chips, and the DSP chip communicates with the FPGA chip through a PCIe interface or an EMIF16 interface.

[0023] In a second aspect, the present invention provides a data acquisition system based on a light and small satellite SAR payload, including a ground control station and the multi-functional device for the light and small satellite SAR payload as described above. The ground control station and the multi-functional device for the light and small satellite SAR payload transmit information through wireless communication.

[0024] (III) Advantageous Effects

[0025] The present invention provides a multi-functional device for a light and small commercial satellite SAR payload. Compared with the prior art, it has the following advantageous effects:

[0026] The present invention provides a multi-functional device for a lightweight and small satellite SAR payload, comprising: a data acquisition module, a data processing module, and a data storage module, and each module is connected through a serial connection method; the data acquisition module is used to transmit a chirp signal, sample the echo signal to obtain original echo data; perform digital decimation, digital filtering, and compression on the original echo data, and send the compressed original echo data to the data storage module; the data processing module is used to process the original echo data stored in the data storage module, and send the processed echo data to the data storage module; the data storage module sends the original echo data and the processed echo data to the data transmission device according to an external control instruction. Among them, the data storage module sends the original data or the processed echo data to the data transmission device through a network or an LVDS interface according to an external control instruction. Each module of the multi-functional device for the lightweight and small satellite SAR payload of the present invention is connected through a high-speed serial connection method, realizing the three major functions of data acquisition, data storage, and data processing with one device, improving the integration degree of the multi-functional device for the SAR payload, reducing the cost of the SAR payload, reducing the volume of the SAR payload, and meeting the requirements of low cost, high integration, and high reliability of the lightweight and small satellite. Description of the Drawings

[0027] In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings required for use in the description of the embodiments or the prior art. Obviously, the following drawings are only some embodiments of the present invention. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative efforts.

[0028] Figure 1 It is a block diagram of the composition of the multi-functional device for the lightweight and small satellite SAR payload in the embodiment of the present invention;

[0029] Figure 2 It is a principle block diagram of the multi-functional device for the lightweight and small satellite SAR payload in the embodiment of the present invention;

[0030] Figure 3 It is a function block diagram implemented by the FPGA of the V7 series in the embodiment of the present invention;

[0031] Figure 4 It is the AD circuit synchronization signal and JESD204B interface circuit in the embodiment of the present invention;

[0032] Figure 5 It is the principle of the DA circuit in the embodiment of the present invention;

[0033] Figure 6 It is the overall structure block diagram of the DSP chip in the embodiment of the present invention;

[0034] Figure 7It is a block diagram of the power supply module of the multi-functional device for the light and small satellite SAR payload in the embodiment of the present invention. Detailed implementation manners

[0035] To make the objectives, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described. Apparently, the described embodiments are some but not all of the embodiments of the present invention. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

[0036] By providing a multi-functional device for a light and small satellite SAR payload in the embodiments of the present application, the technical problem of low integration degree of the existing SAR payload is solved, and the three major functions of data acquisition, data storage and data processing are realized by one device, so as to improve the integration degree of the multi-functional device of the SAR payload, reduce the cost of the SAR payload, and reduce the volume of the SAR payload.

[0037] The technical solutions in the embodiments of the present application to solve the above technical problems are generally as follows:

[0038] Currently, the following problems mainly exist in commercial satellite SAR payloads:

[0039] 1. There are many central electronic devices, and there are also many cables for interconnection between them, which are difficult to meet the requirements of low cost, high integration and high reliability of light and small commercial satellites.

[0040] 2. It can only generate linear frequency modulation pulse signals, filter and amplify, and amplify, filter and collect the original radar echo data, and it is difficult to complete more comprehensive tasks such as target tracking, data compression, data storage and data processing.

[0041] To solve the above problems, the embodiments of the present invention propose a multi-functional device for a light and small satellite SAR payload, especially for the SAR payload of a light and small commercial satellite. This device integrates the three major functions of data acquisition, data storage and data processing. Data acquisition mainly generates linear frequency modulation signals with the required corresponding bandwidth according to system requirements, samples the radar echo signals to obtain the original echo data, performs digital decimation, digital filtering and compression on the original echo data, and sends the compressed data to data storage; the data storage then sends it to data processing for processing, and the processed data is sent back to data storage. The data storage sends the original data or the processed echo data to the data transmission device through the network or LVDS interface according to external control instructions. This device can effectively solve the existing commercial satellite SAR payloads.

[0042] To better understand the above technical solutions, the above technical solutions will be described in detail below in conjunction with the accompanying drawings of the specification and specific implementation manners.

[0043] A multi-functional device for a lightweight satellite SAR payload according to an embodiment of the present invention, as Figure 1 shown, includes: a data acquisition module, a data processing module, and a data storage module, and each module is connected through a serial connection method;

[0044] Among them, the data acquisition module is used to transmit a chirp signal, sample the echo signal to obtain original echo data; perform digital decimation, digital filtering, and compression on the original echo data, and send the compressed original echo data to the data storage module;

[0045] The data processing module is used to process the original echo data stored in the data storage module, and send the processed echo data to the data storage module;

[0046] The data storage module sends the original echo data and the processed echo data to the data transmission device according to an external control instruction.

[0047] It should be noted that the multi-functional device for the lightweight satellite SAR payload according to the embodiment of the present invention is connected to the main control device through LVDS communication to receive external control instructions.

[0048] Each module of the multi-functional device for the lightweight satellite SAR payload according to the embodiment of the present invention is connected through a serial connection method, realizing the three major functions of data acquisition, data storage, and data processing with one device, improving the integration degree of the SAR payload multi-functional device, reducing the cost of the SAR payload, reducing the volume of the SAR payload, and meeting the requirements of low cost, high integration, and high reliability of lightweight commercial satellites.

[0049] The principle block diagram of the multi-functional device for the lightweight satellite SAR payload is as Figure 2 shown.

[0050] The following is a detailed description of each module:

[0051] Data acquisition module:

[0052] As Figure 3 shown, the data acquisition module consists of 2 ADCs, 2 DACs, and 1 V7 FPGA (XC7VX690T), and mainly completes the acquisition of analog signals.

[0053] The FPGA selects XC7VX690T of XILINX. XC7VX690T has 693,120 logic cells, and 108,300 Slices support a maximum of 1,000 user IOs.

[0054] The FPGA mainly implements the functions of AD acquisition, DA intermediate frequency generation, communication with the DSP through PCIe (or EMIF interface) and serial port, LVDS communication with the main control Z7030, and read / write control functions of DDR3 and NAND FLASH. The FPGA is configured with 16 eMMCs, with a supply voltage of 3.3V, a single-chip capacity of 16GB, a bit width of 8bit, and a clock frequency of 52MHz. The FPGA is configured with 2 DDR3 memory chips, with a supply voltage of 1.5V, a single-chip capacity of 256M×16bit, 2 chips are used, the total capacity is 1Gbyte, the bit width is 32bit, the transmission rate is 1600MT / S, and the clock frequency is 800MHz.

[0055] Figure 3 The design of the AD circuit in Figure 4 is shown as follows. The design of the AD circuit mainly includes the AD front-end sampling clock circuit, analog input terminal, SYSREF and SYNC circuit, JESD204B serial data stream circuit, and power supply circuit. For the SYSREF and SYNC circuit, the 9525 from ADI is used to generate the synchronization signals for 7 ADs to ensure the synchronous acquisition of 2 ADs.

[0056] The design of the DA circuit is as Figure 5 shown. The DA chip from ADI is selected for the DA circuit, which is connected to the FPGA through the LVDS bus, and the parameters are set through the SPI bus.

[0057] Data storage module:

[0058] Data storage consists of 1 V7 FPGA (XC7VX690T, sharing the FPGA with data acquisition) and two mSATA disks, mainly for storing the original echo data and the echo data after data processing.

[0059] The front-end AD acquisition and the echo data processed by the DSP are both written to the disk under the control of the V7 FPGA. The mSATA disks mounted on the board communicate with the V7 FPGA through the SATA3.0 high-speed bus. SATA3.0 supports a maximum transmission rate of 6Gbps, and the theoretical transmission rate achievable considering the protocol overhead is 4.2Gbps. The storage rate of the mounted mSATA disk is 360MB / s. The capacity of 1 rugged mSATA disk is 512GB, and 2 mSATA disks are placed on the multifunctional device as cold backups.

[0060] Data processing module:

[0061] Data processing is mainly completed by the DSP. The V7 FPGA sends data to the DSP through the RapidIO high-speed bus for data processing. After the DSP finishes processing the data, it is sent back to the mSATA disk for storage through the RapidIO high-speed bus.

[0062] As Figure 6 shown, the DSP selected is the TI SM320C6678ACYPW. It contains 8 M66x DSP cores per chip, with each core operating at a frequency of 1.4 GHz, supporting fixed-point and floating-point operations, having 4 MB of SRAM shared by 8 cores on-chip, and 1 4x RapidIO high-speed serial link, etc.

[0063] The DSP is configured with 4 DDR3 memory chips, with a supply voltage of 1.5 V, a single-chip capacity of 256 M×16 bit, a total capacity of 2 GB, a bit width of 64 bit, a transmission rate of 1600 MT / S, and a clock frequency of 800 MHz. Communication between the DSP and the FPGA is carried out through the PCIe interface (or EMIF16 interface), and the line rate of the PCIe interface is 5 Gbps. The reset input signal of the DSP is provided by the FPGA. The DSP is configured with a nor flash via spi (or emif interface) to store the boot program and application program. Online update of the application program is supported. The application program enters the main control Z7030 from the LVDS bus, reaches the DSP6678 through the EMIF bus interface, and performs online update on the FLASH chip.

[0064] In the specific implementation process, the lightweight satellite SAR payload multifunctional device of the embodiment of the present invention further includes a power supply module.

[0065] The power supply module mainly includes a DC / DC power supply unit, an LDO conversion unit, etc. After the external 12V power supply comes in, it is first converted to 3.3V by the DC / DC power supply unit, and then converted to the power supplies required for each level through the LDO.

[0066] Both the DC / DC unit and the LDO selected for the power supply module can achieve different soft start times by adjusting the external capacitor.

[0067] As Figure 7 shown.

[0068] The lightweight satellite SAR payload multifunctional device is powered by the input VCC_12V power supply. The VCC_12V then supplies 3 LYM4644IY power chips to output the various power supplies required on the multifunctional module.

[0069] The power supply chip LYM4644IY outputs 4-channel power supplies, with 4A for each channel. Three LYM4644IY are used in the multifunctional module to provide power outputs of MGTAVCC_1.0V@4A, MGTAVTT_1.2V@4A, 5V@8A, 2.5V@8A, 1.0V@8A, and 1.3V@16A. These power supplies are respectively output to the FPGA chip XC7VX690T, DDR3, ADC, etc.

[0070] The output voltage range of the LDO power supply chip is 0.8V to 3.6V, and the maximum output current is 3A. Three LDO power supply modules are used to convert 5V to 3.3V@3A, 2.5V to 1.8V@3A, and 2.5V to 1.5V@3A respectively.

[0071] The embodiment of the present invention also provides a data acquisition system based on a lightweight small satellite SAR payload, which includes a ground control station and the lightweight small satellite SAR payload multifunctional device as described above. The ground control station and the lightweight small satellite SAR payload multifunctional device transmit information through wireless communication. The ground control station includes a ground radar control station and a ground satellite control station.

[0072] In summary, compared with the prior art, the following beneficial effects are achieved:

[0073] 1. The various modules of the lightweight small satellite SAR payload multifunctional device in the embodiment of the present invention are connected by a serial connection method, realizing the three functions of data acquisition, data storage, and data processing with one device, improving the integration degree of the SAR payload multifunctional device, reducing the cost of the SAR payload, and reducing the volume of the SAR payload, which can meet the requirements of low cost, high integration, and high reliability of lightweight small commercial satellites.

[0074] 2. Compared with the existing SAR payloads, the lightweight small satellite SAR payload multifunctional device in the embodiment of the present invention can perform more comprehensive tasks such as generating linear frequency modulation pulse signals, filtering, amplifying, amplifying and filtering the original radar echo data, collecting, data compressing, data storing, data processing, and target tracking.

[0075] It should be noted that, in this article, relational terms such as first and second are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any actual relationship or order between these entities or operations. Moreover, the term "comprising", "including" or any other variant thereof is intended to cover non-exclusive inclusion, so that a process, method, article or device comprising a series of elements not only includes those elements, but also includes other elements not expressly listed, or further includes elements inherent to such process, method, article or device. Without further limitation, an element defined by the statement "comprising one..." does not exclude the presence of additional identical elements in the process, method, article or device comprising the said element.

[0076] The above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it; although the present invention has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that they can still modify the technical solutions recorded in the foregoing embodiments, or perform equivalent replacements for some of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A multi-functional device for a lightweight satellite SAR payload, characterized in that, it includes: a data acquisition module, a data processing module, and a data storage module, and each module is connected by a serial connection method; wherein, the data acquisition module is used to transmit a chirp signal, sample the echo signal to obtain original echo data; perform digital decimation, digital filtering, and compression on the original echo data, and send the compressed original echo data to the data storage module; the data processing module is used to process the original echo data stored in the data storage module, and send the processed echo data to the data storage module; the data storage module sends the original echo data and the processed echo data to the data transmission device according to an external control instruction; the external control instruction is sent through a main control device, wherein, the main control device communicates with the multi-functional device for the lightweight satellite SAR payload through LVDS communication; the data acquisition module includes an FPGA chip, two AD circuits, and two DA circuits; the data storage module includes an FPGA chip and an mSATA disk, wherein the FPGA chip shares one chip with the data acquisition module; the data processing module includes a DSP chip and 4 DDR3 memory chips, and the DSP chip communicates with the FPGA chip through a PCIe interface or an EMIF16 interface.

2. The multi-functional device for the lightweight satellite SAR payload according to claim 1, characterized in that, the sending the original echo data and the processed echo data to the data transmission device includes: sending the original echo data and the processed echo data to the data transmission device through wireless communication or LVDS communication.

3. The multi-functional device for the lightweight satellite SAR payload according to claim 1, characterized in that, the multi-functional device for the lightweight satellite SAR payload further includes: a power supply module; the power supply module includes a DC / DC power supply unit and an LDO conversion unit, and the external power supply is converted to 3.3V through the DC / DC power supply unit and then converted through the LDO conversion unit to supply power to the chips in the multi-functional device for the lightweight satellite SAR payload.

4. The multi-functional device for the lightweight satellite SAR payload according to any one of claims 1 to 3, characterized in that, the FPGA chip is connected to the two AD circuits through an LVDS bus to realize sampling of the echo signal; the FPGA chip is connected to the two DA circuits through an LVDS bus to realize generation of an intermediate frequency signal.

5. A data acquisition system based on a lightweight satellite SAR payload, characterized in that, it includes a ground control station and the multi-functional device for the lightweight satellite SAR payload according to any one of claims 1 to 4, and the ground control station and the multi-functional device for the lightweight satellite SAR payload perform information transmission through wireless communication.

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