Occultation detection system and method based on aerostat

Abstract

The embodiment of the present invention discloses an occultation detection system and method based on an aerostat. The system includes: a GNSS occultation antenna array, a GNSS direct antenna, a radio frequency signal processing circuit, a digital signal processing circuit, an anti-fuse FPGA and a FLASH memory; the GNSS occultation antenna array is connected to the radio frequency signal processing circuit, the GNSS direct antenna is connected to the radio frequency signal processing circuit, the radio frequency signal processing circuit is connected to the digital signal processing circuit, the digital signal processing circuit is connected to the anti-fuse FPGA, the anti-fuse FPGA is connected to the FLASH memory, and the FLASH memory is used to store bit stream files. The technical solution of the embodiment of the present invention selects to load bit stream files of different functions to the SOC processor by parsing the telemetry instruction, quickly switches the ionospheric occultation detection function and the atmospheric occultation detection function, and realizes key observation of key areas.

Description

Technical Field

[0001] The embodiments of the present invention relate to space detection technology, and in particular to an aerostat-based occultation detection system and method. Background Art

[0002] In recent years, GNSS (Global Navigation Satellite System) has developed rapidly in countries around the world. Among them, the aerospace industry has entered the commercialization process in many fields, and the application of GNSS remote sensing technology has made breakthrough progress. GNSS remote sensing technology uses the changes in physical quantities such as signal amplitude and phase after radio waves propagate in the earth's atmosphere or are reflected by ground objects to invert meteorological elements such as the earth's atmosphere, ocean and soil. The inversion products of GNSS occultation detection are ionosphere and atmospheric parameters. Ionospheric inversion products include ionospheric electron density profiles and ionospheric scintillation index, and atmospheric inversion products include atmospheric refractive index, density, pressure, temperature, and humidity profiles. It has outstanding characteristics such as low cost, rich and fast data acquisition, and high measurement accuracy, and has extremely broad application prospects. At present, GNSS occultation detection is independently realized by using GNSS occultation receivers, direct antennas, a forward occultation antenna, a backward occultation antenna and an atmospheric occultation antenna installed on airships or low-orbit satellites. In particular, some existing aerostats, such as near-space airships or space airships, can fly at altitudes as high as 100 kilometers. In practical applications, the flight altitude of the aerostat can be adjusted so that the aerostat can detect atmospheric occultation signals or ionospheric occultation signals.

[0003] In the process of realizing the present invention, the inventors found that the prior art has the disadvantages of few occultation channel allocations, heavy weight, high launch cost, and inability to achieve key observations in key areas. Domestic research on lightweight, low-cost, and multi-purpose GNSS occultation detection is still in the preliminary research stage, with little relevant information, and is far behind the research level of NASA (National Aeronautics and Space Administration) and ESA (European Space Agency). Summary of the invention

[0004] The embodiment of the present invention provides an aerostat-based occultation detection system and method, so as to realize the selection of bit stream files with different functions loaded into the processing circuit by parsing the telemetry instruction, quickly switch the ionospheric occultation detection function and the atmospheric occultation detection function, and conduct key observations on key areas.

[0005] In a first aspect, an embodiment of the present invention provides an aerostat-based occultation detection system, comprising:

[0006] GNSS occultation antenna array, GNSS direct antenna, RF signal processing circuit, digital signal processing circuit, anti-fuse FPGA (Field Programmable Gate Array) and FLASH memory;

[0007] The GNSS occultation antenna array is connected to the RF signal processing circuit and is used to receive the GNSS occultation RF signal and send it to the RF signal processing circuit;

[0008] The GNSS direct antenna is connected to the RF signal processing circuit and is used to receive the GNSS direct RF signal and send it to the RF signal processing circuit;

[0009] The radio frequency signal processing circuit is connected to the digital signal processing circuit and is used to process the received GNSS occultation radio frequency signal and GNSS direct radio frequency signal into a GNSS occultation digital baseband signal and a GNSS direct digital baseband signal and send them to the digital signal processing circuit;

[0010] The digital signal processing circuit is connected to the anti-fuse FPGA, and is used to load a bit stream file through the anti-fuse FPGA, and perform digital signal processing on the received GNSS occultation digital baseband signal and the GNSS direct digital baseband signal according to the bit stream file;

[0011] The anti-fuse FPGA is connected to the FLASH memory and is used to obtain a matching bit stream file from the FLASH memory and load it into the digital signal processing circuit according to the instruction parsing result of the ground telemetry instruction;

[0012] The FLASH memory is used to store the bit stream files of the multi-channel ionospheric occultation detection function, the bit stream files of the multi-channel atmospheric occultation detection function and the bit stream files of the standard function.

[0013] Optionally, the radio frequency signal processing circuit specifically includes:

[0014] GNSS occultation radio frequency signal processing subcircuit and GNSS direct radio frequency signal processing subcircuit, wherein:

[0015] The GNSS occultation radio frequency signal processing subcircuit is connected to the GNSS occultation antenna array and the digital signal processing circuit respectively; the GNSS direct radio frequency signal processing subcircuit is connected to the GNSS direct antenna and the digital signal processing circuit respectively;

[0016] The GNSS occultation radio frequency signal processing subcircuit and the GNSS direct radio frequency signal processing subcircuit both include: a connected amplification and filtering circuit and a radio frequency processing chip;

[0017] The amplification and filtering circuit is connected to the GNSS occultation antenna array or the GNSS direct antenna, and is used to amplify and filter the received GNSS occultation radio frequency signal or the GNSS direct radio frequency signal;

[0018] The radio frequency processing chip is connected to the digital signal processing circuit and is used to process the radio frequency signal after amplification and filtering into a digital baseband signal.

[0019] Optionally, the digital signal processing circuit includes: a PS part and a PL part of a SOC processor, wherein:

[0020] The PL part of the SOC processor is connected to the GNSS occultation radio frequency signal processing sub-circuit and the anti-fuse FPGA respectively, and is used to process the received GNSS occultation digital baseband signal into a GNSS occultation ionosphere digital baseband signal or a GNSS occultation atmosphere digital baseband signal according to the bit stream file of the multi-channel ionospheric occultation detection function or the bit stream file of the multi-channel atmospheric occultation detection function loaded through the anti-fuse FPGA, and send the received GNSS occultation digital baseband signal to the PS part of the SOC processor after digital pre-processing;

[0021] The PS part of the SOC processor is respectively connected to the GNSS direct RF signal processing sub-circuit and the anti-fuse FPGA, and is used to perform digital preprocessing on the received GNSS direct digital baseband signal according to the standard bit stream file loaded through the anti-fuse FPGA, and then perform digital analysis processing on the preprocessed GNSS direct digital baseband signal, the received preprocessed GNSS occultation ionosphere digital baseband signal, or the GNSS occultation atmosphere digital baseband signal.

[0022] Optionally, the GNSS occultation antenna array includes: a 1*4 antenna array and a GNSS occultation radio frequency signal synthesis unit; each antenna in the 1*4 antenna array is respectively connected to the GNSS occultation radio frequency signal synthesis unit;

[0023] The GNSS occultation radio frequency signal synthesis unit includes a GNSS occultation antenna synthesis network, which is connected to the GNSS occultation radio frequency signal processing subcircuit, and is used to synthesize the signals received by each antenna into the GNSS occultation radio frequency signal.

[0024] Optionally, the anti-fuse FPGA exchanges data with the PL part of the SOC processor, the PS part of the SOC processor, and the FLASH memory through a SelectMAP interface.

[0025] Optionally, the anti-fuse FPGA includes a ground telemetry bus interface, and the ground telemetry bus interface is used to connect to a ground telemetry bus and receive the ground telemetry instruction through the ground telemetry bus;

[0026] The ground telemetry instructions include: an ionospheric occultation detection function start-up instruction and an atmospheric occultation detection function start-up instruction.

[0027] Optionally, the bitstream file of the standard function is stored in the CE0 storage space in the FLASH memory;

[0028] The bitstream file of the multi-channel ionospheric occultation detection function is stored in the CE1 storage space in the FLASH memory;

[0029] The bitstream file of the multi-channel atmospheric occultation detection function is stored in the CE2 storage space in the FLASH memory.

[0030] In a second aspect, an embodiment of the present invention further provides an aerostat-based occultation detection method, comprising:

[0031] When the anti-fuse FPGA detects the power-on startup command, it obtains the ground telemetry command for command analysis;

[0032] The anti-fuse FPGA obtains a matching bit stream file from the FLASH memory according to the instruction parsing result of the ground telemetry instruction and loads it into the digital signal processing circuit, so that the signal processing circuit performs the matching occultation detection function according to the loaded bit stream file;

[0033] The FLASH memory is used to store the bitstream files of the multi-channel ionospheric occultation detection function, the bitstream files of the multi-channel atmospheric occultation detection function and the bitstream files of the standard function.

[0034] Optionally, the digital signal processing circuit specifically includes: a PS part and a PL part of a SOC processor;

[0035] The anti-fuse FPGA obtains a matching bit stream file from the FLASH memory and loads it into the digital signal processing circuit according to the instruction parsing result of the ground telemetry instruction, including:

[0036] If the anti-fuse FPGA determines that the instruction parsing result is no instruction information or an ionospheric occultation detection function start instruction, the bit stream file of the standard function is obtained from the FLASH memory and loaded into the PS part of the SOC processor, and the bit stream file of the multi-channel ionospheric occultation detection function is obtained from the FLASH memory and loaded into the PL part of the SOC processor;

[0037] If the anti-fuse FPGA determines that the instruction parsing result is an atmospheric occultation detection function startup instruction, it obtains the bitstream file of the standard function from the FLASH memory and loads it into the PS part of the SOC processor, and obtains the bitstream file of the multi-channel atmospheric occultation detection function from the FLASH memory and loads it into the PL part of the SOC processor.

[0038] Optionally, after the anti-fuse FPGA obtains a matching bit stream file from the FLASH memory and loads it into the digital signal processing circuit according to the instruction parsing result of the ground telemetry instruction, it also includes:

[0039] During normal operation of the anti-fuse FPGA, if a new ground telemetry instruction is detected, the anti-fuse FPGA performs instruction parsing on the new ground telemetry instruction;

[0040] If the anti-fuse FPGA determines that the instruction parsing result is an ionospheric occultation detection function startup instruction, and the currently enabled occultation detection function is an atmospheric occultation detection function, then a bit stream file of a standard function is obtained from the FLASH memory and loaded into the PS part of the SOC processor, and a bit stream file of a multi-channel ionospheric occultation detection function is obtained from the FLASH memory and loaded into the PL part of the SOC processor, and the PS part and the PL part of the SOC processor are reset;

[0041] If the anti-fuse FPGA determines that the instruction parsing result is an atmospheric occultation detection function startup instruction, and the currently enabled occultation detection function is an ionospheric occultation detection function, then the bitstream file of the standard function is obtained from the FLASH memory and loaded into the PS part of the SOC processor, and the bitstream file of the multi-channel atmospheric occultation detection function is obtained from the FLASH memory and loaded into the PL part of the SOC processor, and the PS part and PL part of the SOC processor are reset.

[0042] The embodiment of the present invention receives ground telemetry bus instructions through an anti-fuse FPGA, selects to load bitstream files with different functions to the SOC processor by parsing the instructions, and quickly switches the ionospheric occultation detection and atmospheric occultation detection functions, thereby solving the problems of small occultation channel allocation, large weight, high launch cost, and inability to achieve key observations in key areas, and realizes the real-time and flexible configuration of occultation channels to achieve the effect of key observations in key areas. BRIEF DESCRIPTION OF THE DRAWINGS

[0043] Figure 1 This is a structural block diagram of an aerostat-based occultation detection system in Embodiment 1 of the present invention;

[0044] Figure 2a This is a structural block diagram of an aerostat-based occultation detection system in Embodiment 2 of the present invention;

[0045] Figure 2b is a telemetry instruction parsing flow chart in Embodiment 2 of the present invention;

[0046] Figure 2c It is the FLASH memory storage bit stream file allocation map in the second embodiment of the present invention;

[0047] Figure 3 This is a flow chart of an aerostat-based occultation detection method in Embodiment 3 of the present invention. DETAILED DESCRIPTION

[0048] The present invention will be further described in detail below in conjunction with the accompanying drawings and embodiments. It is to be understood that the specific embodiments described herein are only used to explain the present invention, rather than to limit the present invention. It should also be noted that, for ease of description, only parts related to the present invention, rather than all structures, are shown in the accompanying drawings.

[0049] Embodiment 1

[0050] Figure 1 This is a structural block diagram of an aerostat-based occultation detection system provided in the first embodiment of the present invention. This embodiment can be used to quickly switch between ionospheric occultation detection and atmospheric occultation detection functions through telemetry commands, so as to realize the real-time and flexible configuration of occultation channels and focus on key areas. Figure 1 As shown, the system includes:

[0051] The GNSS occultation antenna array 110 , the GNSS direct antenna 120 , the radio frequency signal processing circuit 130 , the digital signal processing circuit 140 , the anti-fuse FPGA 150 and the FLASH memory 160 .

[0052] It should be noted that the occultation detection system provided by the embodiment of the present invention can be configured on an aerostat to realize the above-mentioned occultation detection function, wherein the aerostat can be an airship (near-space airship or space airship), etc. Typically, the aerostat adapted by the embodiment of the present invention is generally a small aerostat.

[0053] The GNSS occultation antenna array 110 is connected to the RF signal processing circuit 130 and is used to receive the GNSS occultation RF signal and send it to the RF signal processing circuit 130;

[0054] The GNSS direct antenna 120 is connected to the RF signal processing circuit 130 and is used to receive the GNSS direct RF signal and send it to the RF signal processing circuit 130;

[0055] The direct radio frequency signal for realizing the GNSS navigation, positioning and orbit determination function is received by the GNSS direct antenna 120. The GNSS navigation, positioning and orbit determination function is used to provide accurate positioning information and time reference for different working modes, thereby ensuring the accuracy of the data processing information obtained on this basis.

[0056] The RF signal processing circuit 130 is connected to the digital signal processing circuit 140, and is used to process the received GNSS occultation RF signal and GNSS direct RF signal into a GNSS occultation digital baseband signal and a GNSS direct digital baseband signal and send them to the digital signal processing circuit 140;

[0057] Among them, the RF signal processing circuit 130 is used to process the RF signals received from the GNSS occultation antenna array 110 and the GNSS direct antenna 120 into digital baseband signals, and the RF signal processing circuit 130 includes multiple output channels, supporting the output of signals of different frequency bands to the digital signal processing circuit 140.

[0058] The digital signal processing circuit 140 is connected to the anti-fuse FPGA 150, and is used to load a bit stream file through the anti-fuse FPGA 150, and perform digital signal processing on the received GNSS occultation digital baseband signal and the GNSS direct digital baseband signal according to the bit stream file;

[0059] Among them, the digital signal processing circuit 140 determines the current working mode according to the bitstream file loaded through the anti-fuse FPGA150. In the occultation detection system in this embodiment, there are two working modes, namely, the working mode of the ionospheric occultation detection function and the working mode of the atmospheric occultation detection function. After the digital signal processing circuit 140 determines the working mode according to the type of the loaded bitstream file, it receives the GNSS direct digital baseband signal, and collects and processes the GNSS occultation digital baseband signal into matching occultation detection information. For example, when working in the working mode of the ionospheric occultation detection function, the digital signal processing circuit 140 collects and processes the GNSS occultation digital baseband signal into the GNSS occultation ionospheric digital baseband signal; when working in the working mode of the atmospheric occultation detection function, the digital signal processing circuit 140 collects and processes the GNSS occultation digital baseband signal into the GNSS occultation atmospheric digital baseband signal.

[0060] At the same time, the digital signal processing circuit 140 can set the circuit parameters of the RF signal processing circuit 130 according to the required bandwidth of the digital baseband signal, so that the RF signal processing circuit 130 provides a digital baseband signal that meets the requirements, thereby obtaining accurate analysis data and correctly detecting target information.

[0061] The anti-fuse FPGA 150 is connected to the FLASH memory 160 and is used to obtain a matching bit stream file from the FLASH memory 160 and load it into the digital signal processing circuit 140 according to the instruction parsing result of the ground telemetry instruction;

[0062] Among them, the anti-fuse FPGA 150 receives and analyzes the ground telemetry instructions in real time, determines the working mode of the occultation detection system in this embodiment according to the instruction analysis result, and thus selects the corresponding bit stream file from the FLASH memory 160 to load it into the digital signal processing circuit 140, and when the ground telemetry instructions change, the anti-fuse FPGA 150 can refresh the digital signal processing circuit 140 according to the instruction analysis result to ensure that the bit stream file loaded into the digital signal processing circuit 140 is consistent with the ground telemetry instructions. For example, after power-on, the anti-fuse FPGA 150 determines that the instruction analysis result is an ionospheric occultation detection function startup instruction, then obtains the bit stream file associated with the ionospheric occultation detection function from the FLASH memory 160 and The ground telemetry instruction is loaded into the digital signal processing circuit 140, and then the ground telemetry instruction changes. According to the real-time analysis result of the anti-fuse FPGA 150, it is determined that the ground telemetry instruction becomes the atmospheric occultation detection function start instruction, then the bit stream file matching the atmospheric occultation detection function is obtained from the FLASH memory 160 and loaded into the digital signal processing circuit 140, and the digital signal processing circuit 140 is reset to make the occultation detection system work in the working mode of the atmospheric occultation detection function. Optionally, when the anti-fuse FPGA 150 receives and analyzes the ground telemetry instruction in real time as no instruction information, it is considered that the current working mode is the working mode of the ionospheric occultation detection function, and the matching bit stream file is loaded into the digital signal processing circuit 140.

[0063] The FLASH memory 160 is used to store the bit stream files of the multi-channel ionospheric occultation detection function, the bit stream files of the multi-channel atmospheric occultation detection function and the bit stream files of the standard function.

[0064] Among them, the bitstream file of the standard function is used to process the GNSS direct digital baseband signal to provide accurate positioning information and time reference for all working modes; the bitstream file of the multi-channel ionospheric occultation detection function is used to perform the working tasks of the ionospheric occultation detection function working mode, corresponding to the operation of preprocessing the GNSS occultation ionospheric digital baseband signal after the GNSS occultation digital baseband signal is collected and processed into the GNSS occultation ionospheric digital baseband signal; the bitstream file of the multi-channel atmospheric occultation detection function is used to perform the working tasks of the atmospheric occultation detection function working mode, corresponding to the operation of preprocessing the GNSS occultation atmospheric digital baseband signal after the GNSS occultation digital baseband signal is collected and processed into the GNSS atmospheric ionosphere digital baseband signal.

[0065] Among them, the completion signal flow of this embodiment is as follows: the GNSS occultation antenna array 110 generates a GNSS occultation RF signal and sends it to the RF signal processing circuit 130, the GNSS direct antenna 120 generates a GNSS direct RF signal and sends it to the RF signal processing circuit 130, the RF signal processing circuit 130 processes the received RF signal to generate a digital baseband signal, and sends it to the digital signal processing circuit 140, the anti-fuse FPGA 150 receives and analyzes the ground telemetry instructions in real time on the ground, and obtains the matching bit stream file from the FLASH memory 160 according to the analysis result of the telemetry instruction result and loads it into the digital signal processing circuit 140, the digital signal processing circuit 140 collects the corresponding signal (GNSS occultation ionosphere digital baseband signal or GNSS occultation atmosphere digital baseband signal), pre-processes and digitally analyzes the received digital baseband signal according to the loaded bit stream file, and obtains the parameters required to execute the matching occultation detection function.

[0066] The existing technology requires a GNSS occultation receiver, a direct antenna, a forward occultation antenna, a backward occultation antenna, and an atmospheric occultation antenna to realize GNSS occultation detection. Compared with the existing technology, the technical solution of the embodiment of the present invention reduces the number of required devices while ensuring the normal execution of the GNSS occultation detection function, and solves the problems of heavy weight and high transmission cost of hardware resources and antenna resources required for occultation detection in the existing technology. In the embodiment of the present invention, the anti-fuse FPGA receives the ground telemetry bus instruction, and the SOC processor is selected to load the bit stream file with different functions by parsing the instruction, and the ionospheric occultation detection and atmospheric occultation detection functions are quickly switched, which solves the problem of insufficient allocation of occultation channels and the inability to realize key observations in key areas, and realizes the real-time and flexible configuration of occultation channels, and the effect of key observations in key areas.

[0067] Embodiment 2

[0068] like Figure 2a As shown, in this embodiment, a specific structural block diagram of an occultation detection system based on an aerostat is provided.

[0069] In the embodiment of the present invention, optionally, based on the above-mentioned occultation detection system, the RF signal processing circuit specifically includes: a GNSS occultation RF signal processing subcircuit 131 and a GNSS direct RF signal processing subcircuit 132 .

[0070] The GNSS occultation RF signal processing subcircuit 131 is connected to the GNSS occultation antenna array 110 and the digital signal processing circuit 140, respectively. The GNSS direct RF signal processing subcircuit 132 is connected to the GNSS direct antenna 120 and the digital signal processing circuit 140, respectively. The GNSS occultation RF signal processing subcircuit 131 and the GNSS direct RF signal processing subcircuit 132 both include: a connected amplification and filtering circuit 1321 and a RF processing chip 1322.

[0071] Optionally, the amplifying and filtering circuit 1321 is composed of at least one amplifier and at least one filter. The input end of the amplifying and filtering circuit 1321 is connected to the GNSS occultation antenna array 110, and can perform low-noise amplification and RF filtering on the received GNSS occultation RF signal; the RF processing chip 1322 is connected to the digital signal processing circuit 140, and can process the RF signal processed by the amplifying and filtering circuit 1321 into a digital baseband signal, and send the digital baseband signal to the digital signal processing circuit 140 for digital signal processing.

[0072] The radio frequency processing chip includes a plurality of configurable parameters, for example, parameters such as the frequency band range of the received signal or the amplification factor, and the above configurable parameters can be set by the connected digital signal processing circuit 140 .

[0073] Optionally, the digital signal processing circuit 140 may be a SOC processor, and in particular, a high-performance SOC processor may be selected. The SOC processor includes a PS part 142 and a PL part 141 .

[0074] In an embodiment of the present invention, the SOC processor may include the Zynq-7000 series SOC processor of Xilinx, which integrates the software programmability of the ARM processor and the hardware programmability of the FPGA, and can realize important analysis and hardware acceleration. The Zynq-7000 series SOC processor includes at least a PS (Processing System) part and a PL (Progarmmable Logic) part, wherein the PS part 142 is the ARM part of the SOC processor that is unrelated to the FPGA (Field Programmable Gate Array), and the PL part 141 is the FPGA part. The FPGA part may include Xilinx SoC, MPSoC, RFSoC and other series FPGAs of Xilinx and FPGAs of other types manufactured by other companies that can support burning bitstream files.

[0075] The PL part 141 of the SOC processor is respectively connected to the GNSS occultation RF signal processing sub-circuit 131 and the anti-fuse FPGA 150. It can process the received GNSS occultation digital baseband signal into a GNSS occultation ionospheric digital baseband signal or a GNSS occultation atmospheric digital baseband signal according to the bit stream file of the multi-channel ionospheric occultation detection function or the bit stream file of the multi-channel atmospheric occultation detection function loaded through the anti-fuse FPGA 150, and send it to the PS part 142 of the SOC processor after digital pre-processing.

[0076] The PS part 142 of the SOC processor is respectively connected to the GNSS direct RF signal processing sub-circuit 132 and the anti-fuse FPGA 150. It can digitally pre-process the received GNSS direct digital baseband signal according to the standard bit stream file loaded through the anti-fuse FPGA 150, and digitally analyze and process the pre-processed GNSS direct digital baseband signal and the received pre-processed GNSS occultation ionosphere digital baseband signal or the GNSS occultation atmosphere digital baseband signal.

[0077] The PS part 142 of the SOC processor performs digital analysis processing on the pre-processed digital baseband signal, including: the PS part 142 of the SOC processor performs data collection on the collected occultation events to obtain the parameters required for performing the matching occultation detection function. The parameters required for performing ionospheric occultation detection include: ionospheric electron density profile and ionospheric scintillation index, and the parameters required for performing atmospheric occultation detection include: atmospheric refractive index, density, pressure, temperature and humidity profile.

[0078] In one implementation of the embodiment of the present invention, optionally, based on the above-mentioned occultation detection system, the GNSS occultation antenna array 110 includes: a 1*4 antenna array 111 and a GNSS occultation radio frequency signal synthesis unit 112; wherein each antenna in the 1*4 antenna array 111 is respectively connected to the GNSS occultation radio frequency signal synthesis unit 112, and the GNSS occultation radio frequency signal synthesis unit 112 includes a GNSS occultation antenna synthesis network, which can synthesize the signals received by each antenna in the 1*4 antenna array 111 into a GNSS occultation radio frequency signal. The GNSS occultation antenna synthesis network is connected to the GNSS occultation radio frequency signal processing subcircuit 131, and the synthesized GNSS occultation radio frequency signal is amplified and filtered by the GNSS occultation radio frequency signal processing subcircuit 131.

[0079] In an embodiment of the present invention, the GNSS positioning and orbit determination function can be realized by using the GNSS direct antenna 120. The GNSS positioning function can provide positioning information and time reference for the GNSS ionospheric occultation detection and the GNSS atmospheric occultation detection. Moreover, when the GNSS ionospheric occultation detection and the GNSS atmospheric occultation detection functions are switched, the GNSS positioning function is not interrupted.

[0080] In one implementation of the present invention, optionally, based on the above-mentioned occultation detection system, the anti-fuse FPGA 150 exchanges data with the PL part 141 of the SOC processor, the PS part 142 of the SOC processor and the FLASH memory 160 through the SelectMAP interface 170 .

[0081] In this embodiment, the anti-fuse FPGA 150 may include Actel's A54SX72 series anti-fuse FPGA, which has the functions of receiving instructions, system monitoring, and refreshing the SOC processor. Figure 2b As shown, the anti-fuse FPGA 150 includes a ground telemetry bus interface 151 and a ground telemetry instruction parsing unit 152. The ground telemetry bus interface 151 is connected to the ground telemetry bus 170 and receives the ground telemetry instruction through the ground telemetry bus 170; the ground telemetry instruction parsing unit 152 is connected to the ground telemetry bus interface 151 and parses the received ground telemetry instruction; wherein the ground telemetry instruction includes: an ionospheric occultation detection function start instruction and an atmospheric occultation detection function start instruction. In this embodiment, the anti-fuse FPGA 150 receives the ground telemetry instruction in real time through the ground telemetry bus interface 151, and parses the received ground telemetry instruction through the ground telemetry instruction parsing unit 152. According to the parsed telemetry instruction result, the bit stream files of different functions are selected from the FLASH memory 160 through the SelectMAP interface 180 and loaded to the PL part 141 of the SOC processor and the PS part 142 of the SOC processor respectively, so as to realize the working mode of the real-time refresh system.

[0082] Optionally, the ground telemetry bus 170 is used to connect to one or more ground telemetry command transmitters (eg, a ground control station).

[0083] The working modes include ionospheric occultation detection mode and atmospheric occultation detection mode. The ionospheric occultation detection mode is to allocate the PL part of the hardware resources in the SOC processor to the GNSS ionospheric occultation detection channel; the atmospheric occultation detection mode is to allocate the PL part of the hardware resources in the SOC processor to the GNSS atmospheric occultation detection channel. By allocating detection channels according to working modes instead of allocating detection channels to two different detection modes, it is possible to achieve more digital correlation channels for data collection preprocessing for the same working mode, collect more occultation events, and achieve precise detection of special areas.

[0084] Optional, such as Figure 2c As shown, program files need to be stored in advance in the FLASH memory 160, wherein the CE0 storage space 161 of the FLASH memory 160 stores bitstream files of standard functions, the CE1 storage space 162 stores bitstream files of multi-channel ionospheric occultation detection functions, and the CE2 storage space 163 stores bitstream files of multi-channel atmospheric occultation detection functions, wherein the bitstream files in the FLASH memory 160 can be loaded into the SOC processor through the SelectMAP interface.

[0085] Among them, at least three CE chip selects are set in the FLASH memory 6, which are used to store different types of bitstream files. The bitstream files of standard functions are used to process GNSS direct digital baseband signals to provide accurate positioning information and time reference for all working modes; the bitstream files of the multi-channel ionospheric occultation detection function perform the working tasks of the ionospheric occultation detection function working mode; the bitstream files of the multi-channel atmospheric occultation detection function are used to perform the working tasks of the atmospheric occultation detection function working mode.

[0086] In this optional technical solution, different types of bitstream files are stored in independent chip select areas, which is convenient for calling bitstream files and program settings.

[0087] Embodiment 3

[0088] Figure 3 This is a flow chart of an occultation detection method based on an aerostat provided in the third embodiment of the present invention, which is applied to the occultation detection system based on an aerostat described in any embodiment of the present invention. This embodiment is applicable to the case where the anti-fuse FPGA receives the ground telemetry bus instruction, and the SOC processor is loaded with bit stream files of different functions by parsing the instruction, and the ionospheric occultation detection and atmospheric occultation detection functions are quickly switched. Figure 3 As shown, the method includes:

[0089] Step 310: Obtain and parse ground telemetry instructions;

[0090] In this embodiment, when a power-on startup instruction is detected, the anti-fuse FPGA obtains the ground telemetry instruction and performs instruction parsing on the ground telemetry instruction.

[0091] Step 320: according to the instruction parsing result, the corresponding bit stream file is loaded into the digital signal processing circuit to execute the matching occultation detection function;

[0092] The anti-fuse FPGA obtains a matching bit stream file from the FLASH memory according to the command parsing result of the ground telemetry command and loads it into the digital signal processing circuit, so that the digital signal processing circuit executes the matching occultation detection function according to the loaded bit stream file;

[0093] The FLASH memory stores bit stream files of a multi-channel ionospheric occultation detection function, a multi-channel atmospheric occultation detection function, and a bit stream file of a standard function.

[0094] The technical solution of the embodiment of the present invention receives ground telemetry bus instructions through an anti-fuse FPGA, selects to load bitstream files with different functions to the SOC processor by parsing the instructions, and quickly switches the ionospheric occultation detection and atmospheric occultation detection functions, thereby solving the problem of not being able to focus on key areas and achieving the effect of real-time and flexible configuration of occultation channels and focusing on key areas.

[0095] In one implementation of an embodiment of the present invention, optionally, based on the above-mentioned aerostat-based occultation detection method, the anti-fuse FPGA obtains ground telemetry instructions and parses the ground telemetry instructions, including: the anti-fuse FPGA obtains ground telemetry instructions from the ground telemetry bus through the ground telemetry bus interface and parses the instructions.

[0096] Optionally, based on the above-mentioned aerostat-based occultation detection method, the anti-fuse FPGA obtains the matching bit stream file from the FLASH memory and loads it into the digital signal processing circuit, including: the anti-fuse FPGA obtains the matching bit stream file from the FLASH memory through the SelectMAP interface, and loads the matching bit stream file into the digital signal processing circuit through the SelectMAP interface.

[0097] Optionally, based on the above-mentioned aerostat-based occultation detection method, the digital signal processing circuit may be a high-performance SOC processor, and the high-performance SOC processor includes a PS part and a PL part;

[0098] According to the command analysis result of the ground telemetry command, the anti-fuse FPGA obtains the matching bit stream file from the FLASH memory and loads it into the digital signal processing circuit, including:

[0099] If the anti-fuse FPGA determines that the instruction parsing result is no instruction information or an ionospheric occultation detection function start instruction, it obtains the bit stream file of the standard function from the FLASH memory and loads it into the PS part of the SOC processor, and obtains the bit stream file of the multi-channel ionospheric occultation detection function from the FLASH memory and loads it into the PL part of the SOC processor;

[0100] The situation of no command information is that no command content is parsed out from the remote control command on the ground.

[0101] During normal operation of the anti-fuse FPGA, if a new ground telemetry instruction is detected, the new ground telemetry instruction is parsed; if it is determined that the instruction parsing result is an ionospheric occultation detection function startup instruction, and the currently enabled occultation detection function is the atmospheric occultation detection function, the bit stream file of the standard function is obtained from the FLASH memory and loaded into the PS part of the SOC processor, and the bit stream file of the multi-channel ionospheric occultation detection function is obtained from the FLASH memory and loaded into the PL part of the SOC processor, and the PS part and PL part of the SOC processor are reset; if it is determined that the instruction parsing result is an atmospheric occultation detection function startup instruction, and the currently enabled occultation detection function is the ionospheric occultation detection function, the bit stream file of the standard function is obtained from the FLASH memory and loaded into the PS part of the SOC processor, and the bit stream file of the multi-channel atmospheric occultation detection function is obtained from the FLASH memory and loaded into the PL part of the SOC processor, and the PS part and PL part of the SOC processor are reset.

[0102] The purpose of resetting the PS part and the PL part of the SOC processor is to enable the PS part and the PL part of the SOC processor to execute new operations instead of executing previous functions.

[0103] In an embodiment of the present invention, when a power-on startup instruction is detected, the anti-fuse FPGA first determines whether there is a telemetry instruction on the ground telemetry bus. If no telemetry instruction for the system is parsed, the following operations are performed in sequence: first, the bit stream file of the standard function in the CE0 storage space in the FLASH program memory is loaded to the PS part of the SOC processor, and then the bit stream file of the multi-channel ionospheric occultation detection function in the CE1 storage space in the FLASH memory is loaded to the PL part of the SOC processor.

[0104] During or after the execution of the above operations, when the anti-fuse FPGA detects a new telemetry bus instruction and the instruction parsing result is an ionospheric occultation detection function startup instruction, the current system operation state is kept unchanged; if the anti-fuse FPGA determines that the instruction parsing result is an atmospheric occultation detection function startup instruction, the bit stream file of the standard function is obtained from the FLASH memory and loaded into the PS part of the SOC processor, and the bit stream file of the multi-channel atmospheric occultation detection function is obtained from the CE2 storage space of the FLASH memory and loaded into the PL part of the SOC processor, and the PS part and PL part of the SOC processor are reset.

[0105] In an embodiment of the present invention, if a telemetry bus instruction is detected and parsed as an atmospheric occultation detection function start-up instruction, the anti-fuse FPGA selects the bit stream file of the multi-channel atmospheric occultation detection function in the CE2 storage space in the FLASH memory, loads it to the PL part of the SOC processor through the SelectMP dedicated interface, and quickly refreshes the PL part of the SOC processor to quickly implement functional changes and achieve key observation tasks in a certain area.

[0106] Note that the above are only preferred embodiments of the present invention and the technical principles used. Those skilled in the art will understand that the present invention is not limited to the specific embodiments described herein, and that various obvious changes, readjustments and substitutions can be made by those skilled in the art without departing from the scope of protection of the present invention. Therefore, although the present invention has been described in more detail through the above embodiments, the present invention is not limited to the above embodiments, and may include more other equivalent embodiments without departing from the concept of the present invention, and the scope of the present invention is determined by the scope of the appended claims.

Claims

1. An aerostat-based occultation detection system, characterized in that: include: GNSS occultation antenna array, GNSS direct antenna, RF signal processing circuit, digital signal processing circuit, anti-fuse FPGA and FLASH memory; The GNSS occultation antenna array is connected to the RF signal processing circuit and is used to receive the GNSS occultation RF signal and send it to the RF signal processing circuit; The GNSS direct antenna is connected to the RF signal processing circuit and is used to receive the GNSS direct RF signal and send it to the RF signal processing circuit; The RF signal processing circuit is connected to the digital signal processing circuit, and is used to process the received GNSS occultation RF signal and GNSS direct RF signal into a GNSS occultation digital baseband signal and a GNSS direct digital baseband signal, and send them to the digital signal processing circuit; wherein the RF signal processing circuit supports outputting signals of different frequency bands to the digital signal processing circuit; The digital signal processing circuit is connected to the anti-fuse FPGA, and is used to load a bit stream file through the anti-fuse FPGA, and perform digital signal processing on the received GNSS occultation digital baseband signal and the GNSS direct digital baseband signal according to the bit stream file; The anti-fuse FPGA is connected to the FLASH memory and is used to obtain a matching bit stream file from the FLASH memory and load it into the digital signal processing circuit according to the instruction parsing result of the ground telemetry instruction; The FLASH memory is used to store the bit stream files of the multi-channel ionospheric occultation detection function, the bit stream files of the multi-channel atmospheric occultation detection function and the bit stream files of the standard function.

2. The occultation detection system according to claim 1, characterized in that: The radio frequency signal processing circuit specifically includes: GNSS occultation radio frequency signal processing subcircuit and GNSS direct radio frequency signal processing subcircuit, wherein: The GNSS occultation radio frequency signal processing subcircuit is connected to the GNSS occultation antenna array and the digital signal processing circuit respectively; the GNSS direct radio frequency signal processing subcircuit is connected to the GNSS direct antenna and the digital signal processing circuit respectively; The GNSS occultation radio frequency signal processing subcircuit and the GNSS direct radio frequency signal processing subcircuit both include: a connected amplification and filtering circuit and a radio frequency processing chip; The amplification and filtering circuit is connected to the GNSS occultation antenna array or the GNSS direct antenna, and is used to amplify and filter the received GNSS occultation radio frequency signal or the GNSS direct radio frequency signal; The radio frequency processing chip is connected to the digital signal processing circuit and is used to process the radio frequency signal after amplification and filtering into a digital baseband signal.

3. The occultation detection system according to claim 2, characterized in that: The digital signal processing circuit comprises: a PS part and a PL part of a SOC processor, wherein: The PL part of the SOC processor is connected to the GNSS occultation radio frequency signal processing sub-circuit and the anti-fuse FPGA respectively, and is used to process the received GNSS occultation digital baseband signal into a GNSS occultation ionosphere digital baseband signal or a GNSS occultation atmosphere digital baseband signal according to the bit stream file of the multi-channel ionospheric occultation detection function or the bit stream file of the multi-channel atmospheric occultation detection function loaded through the anti-fuse FPGA, and send the received GNSS occultation digital baseband signal to the PS part of the SOC processor after digital pre-processing; The PS part of the SOC processor is respectively connected to the GNSS direct RF signal processing sub-circuit and the anti-fuse FPGA, and is used to perform digital preprocessing on the received GNSS direct digital baseband signal according to the standard bit stream file loaded through the anti-fuse FPGA, and then perform digital analysis processing on the preprocessed GNSS direct digital baseband signal, the received preprocessed GNSS occultation ionosphere digital baseband signal, or the GNSS occultation atmosphere digital baseband signal.

4. The occultation detection system according to any one of claims 1 to 3, characterized in that: The GNSS occultation antenna array comprises: a 1*4 antenna array and a GNSS occultation radio frequency signal synthesis unit; each antenna in the 1*4 antenna array is respectively connected to the GNSS occultation radio frequency signal synthesis unit; The GNSS occultation radio frequency signal synthesis unit includes a GNSS occultation antenna synthesis network, which is connected to the GNSS occultation radio frequency signal processing subcircuit, and is used to synthesize the signals received by each antenna into the GNSS occultation radio frequency signal.

5. The occultation detection system according to claim 3, characterized in that: The anti-fuse FPGA exchanges data with the PL part of the SOC processor, the PS part of the SOC processor and the FLASH memory through the SelectMAP interface.

6. The occultation detection system according to any one of claims 1 to 3, characterized in that: The anti-fuse FPGA includes a ground telemetry bus interface, which is used to connect to a ground telemetry bus and receive the ground telemetry instructions through the ground telemetry bus; wherein the ground telemetry instructions include: an ionospheric occultation detection function start-up instruction and an atmospheric occultation detection function start-up instruction.

7. The occultation detection system according to any one of claims 1 to 3, characterized in that: The bitstream file of the standard function is stored in the CE0 storage space in the FLASH memory; The bitstream file of the multi-channel ionospheric occultation detection function is stored in the CE1 storage space in the FLASH memory; The bitstream file of the multi-channel atmospheric occultation detection function is stored in the CE2 storage space in the FLASH memory.

8. An aerostat-based occultation detection method, applied to an aerostat-based occultation detection system as claimed in any one of claims 1 to 7, characterized in that: include: When the anti-fuse FPGA detects the power-on startup command, it obtains the ground telemetry command for command analysis; The anti-fuse FPGA obtains a matching bit stream file from the FLASH memory according to the instruction parsing result of the ground telemetry instruction and loads it into the digital signal processing circuit, so that the signal processing circuit performs the matching occultation detection function according to the loaded bit stream file; The FLASH memory is used to store the bitstream files of the multi-channel ionospheric occultation detection function, the bitstream files of the multi-channel atmospheric occultation detection function and the bitstream files of the standard function.

9. The method according to claim 8, characterized in that The digital signal processing circuit specifically includes: a PS part and a PL part of a SOC processor; The anti-fuse FPGA obtains a matching bit stream file from the FLASH memory and loads it into the digital signal processing circuit according to the instruction parsing result of the ground telemetry instruction, including: If the anti-fuse FPGA determines that the instruction parsing result is no instruction information or an ionospheric occultation detection function start instruction, the bit stream file of the standard function is obtained from the FLASH memory and loaded into the PS part of the SOC processor, and the bit stream file of the multi-channel ionospheric occultation detection function is obtained from the FLASH memory and loaded into the PL part of the SOC processor; If the anti-fuse FPGA determines that the instruction parsing result is an atmospheric occultation detection function startup instruction, it obtains the bitstream file of the standard function from the FLASH memory and loads it into the PS part of the SOC processor, and obtains the bitstream file of the multi-channel atmospheric occultation detection function from the FLASH memory and loads it into the PL part of the SOC processor.

10. The method according to claim 8 or 9, characterized in that: After the anti-fuse FPGA obtains a matching bit stream file from the FLASH memory and loads it into the digital signal processing circuit according to the instruction parsing result of the ground telemetry instruction, it also includes: During normal operation of the anti-fuse FPGA, if a new ground telemetry instruction is detected, the anti-fuse FPGA performs instruction parsing on the new ground telemetry instruction; If the anti-fuse FPGA determines that the instruction parsing result is an ionospheric occultation detection function startup instruction, and the currently enabled occultation detection function is an atmospheric occultation detection function, then a bit stream file of a standard function is obtained from the FLASH memory and loaded into the PS part of the SOC processor, and a bit stream file of a multi-channel ionospheric occultation detection function is obtained from the FLASH memory and loaded into the PL part of the SOC processor, and the PS part and the PL part of the SOC processor are reset; If the anti-fuse FPGA determines that the instruction parsing result is an atmospheric occultation detection function startup instruction, and the currently enabled occultation detection function is an ionospheric occultation detection function, then the bitstream file of the standard function is obtained from the FLASH memory and loaded into the PS part of the SOC processor, and the bitstream file of the multi-channel atmospheric occultation detection function is obtained from the FLASH memory and loaded into the PL part of the SOC processor, and the PS part and PL part of the SOC processor are reset.

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