Earth remote sensing space system

Abstract

The invention relates to a space-based information system for integrated Earth monitoring. The present space-based system comprises a compact and lightweight spacecraft interacting with a distributed ground control complex for receiving and processing images. On board the spacecraft are installed a C-band radar with synthetic aperture (based on an active phased antenna array), optoelectronic cameras with different frequency ranges and AIS signal receivers. An adaptive high-speed radio link for transmitting mission data comprises an X-band active phased antenna array with narrow focused beams, in which the modulation index is automatically selected depending on the estimated distance to the receiving station. The technical effect consists in expanding the information capabilities of the space system and improving the efficiency of data exchange with the ground part.

Description

Technical Field

[0001] This invention relates to the field of space technology, and more specifically, to a radar Earth remote sensing (ERS) space system (SS). Background Technology

[0002] In the modern context of digital information technology development in the Earth remote sensing market, the most relevant changes are the following key quantitative indicators of the quality and performance of space systems: - Significantly reduced cost per square kilometer for space imaging; - Reduce the cost of manufacturing, launching, and operating Earth remote sensing space systems; - Reduce the design and manufacturing costs of spacecraft; - The creation of a universal space bus for spacecraft, which enables the manufacture of spacecraft with optoelectronic payloads of various resolutions and radar payloads based on them. - Reduction in the mass dimension parameters of spacecraft; The possibility of cluster launches of -ERS spacecraft; - Increase the spatial and linear resolution of satellite imaging products without significantly increasing spacecraft mass; - Improve revisit time to regions of interest by increasing the maneuverability of spacecraft (SC) and by rapidly and efficiently creating constellations of spacecraft; -Increase the transmission rate of mission data to ground receiving stations by using narrow-beam airborne antennas with electron beam scanning and dynamic signal modulation schemes. - Use secondary optoelectronic payloads as part of the SC to improve the efficiency of processing radar imaging results; - Reduce the operating costs of terrestrial receiving and control complexes by establishing a network of universal container non-serviceable stations that combine radio frequency bands (X-band reception and S-band reception / transmission) and are automatically controlled from a single center. - Utilize modern digital technologies to effectively plan the use of mission hardware for the ERS SS spacecraft in order to optimize imaging by taking into account priorities, efficiency, weather conditions, and seasonality.

[0003] Various well-known solutions provide solutions to any one or more of the listed aspects. A detailed description of all prior art solutions similar to the proposed invention within the framework of this application would seem inappropriate.

[0004] At the same time, it should be pointed out that a solution can be considered the closest equivalent of the proposed invention in terms of purpose and the number of matching features.

[0005] That is, the image ground portion for data reception and processing disclosed in patent document RU 2460136C2, 27.08.2012 [1] is known, which further includes an S-band transceiver radio link that can be used to transmit control commands to spacecraft.

[0006] Known solutions include an image ground component for data reception and processing integrated with a control complex.

[0007] The ground control complex in the known solutions from [1] uses a robotic antenna-rotating complex operating in the S and X bands. The ground complex for receiving and processing images (and control) is built on an automated workstation, and a high-speed demodulator allows for demodulation of signals using any type of modulation.

[0008] The problem addressed by the proposed invention is to realize the construction of a spacecraft and ground receiving, processing and control complex by the proposed method, while meeting all the aforementioned modern system requirements of the ERS space complex.

[0009] Technical result: Obtain radar images with optimal radio measurement sensitivity levels.

[0010] Another technical result is the achievement of direct downlink mode (simultaneous imaging and image downlink to the receiving station) at rates up to 1.5 Gbps through electronic scanning alone, without any mechanical guidance or drive.

[0011] Another technical outcome is the use of dynamic modulation, which provides an increase in the amount of raw downlink when using a small-aperture antenna as part of a ground receiving station.

[0012] Other technical results achieved by the proposed invention will be clearly indicated in the following sections of the specification, and will be apparent to the expert from the description of the design and operation of the components of the composite. Summary of the Invention

[0013] As an object of the present invention, an Earth remote sensing space system is considered, designed and manufactured, taking into account the combined application of several technologies and design schemes that can significantly improve the main indicators of traditional Earth remote sensing systems.

[0014] According to a detailed embodiment of the present invention, a space-based Earth remote sensing system is provided, comprising: - At least one spacecraft (SC) built on a powered frame of aluminum and / or carbon truss structure and capable of being placed under the fairing of a launch vehicle; - Ground Control Complex (GCC); - Image Ground Part (IGS DRP) used for data reception and processing; -and included in the payload: - Synthetic aperture radar constructed using C-band active phased array antenna (APAA); - A medium-resolution optoelectronic camera in the visible and infrared frequency range; -AIS ship identification signal receiver; - An apparatus for transmitting mission data based on an X-band active phased array using a narrow beam provides an adaptive high-speed X-band radio link with rate control from 480 Mbps to 1.5 Gbps, wherein the modulation index is automatically selected by the control system based on the estimated relative distance to the receiving station.

[0015] The radar payload constructed using a planar C-band APAA allows for radar imagery with optimal levels of radio measurement sensitivity.

[0016] Constructing APAA as a digital antenna array can increase the overall reliability of the system by using digital beamforming for transmission and reception.

[0017] This solution allows for the use of 2-3 operational control devices (including one of three central control devices) to ensure system operability with a slight reduction in functionality.

[0018] As airborne equipment for transmitting mission data via a radio link, a solution is used that includes an encoder-modulator and two APAA monoliths with narrow beams in the X-band.

[0019] This solution allows for direct downlink mode (simultaneous imaging and image downlink to the receiving station) at rates up to 1.5 Gbps, without any mechanical guide drive, relying solely on electronic scanning.

[0020] The device also uses dynamic modulation, and the modulation index is automatically selected by the control system based on the estimated relative distance to the receiving station. When a small aperture antenna is used as part of the ground receiving station, the amount of the original downstream downlink increases by up to 2 times.

[0021] In an embodiment of the invention, the GCC and IGS DRP stations are located in non-serviceable containers that operate in an automated mode and are controlled from a single data processing center.

[0022] This invention provides solutions to many complex aspects. Therefore, in order to better understand the nature of this invention, the relevant results will be illustrated below with a direct description of its essential features in the detailed description of the invention. Attached Figure Description

[0023] To more fully disclose the essence of the proposed invention, the invention is illustrated with accompanying drawings, which are presented according to the following figures: Figure 1 -ERS SS composition.

[0024] Figure 2A , Figure 2B -External view of the SC structure.

[0025] Figure 3 - A view of the SC for transport configuration.

[0026] Figure 4A , Figure 4B - A view of the SC in flight configuration.

[0027] Figure 5-6 - A dimension diagram of the SC for transmission configuration.

[0028] Figure 7 -APAA view.

[0029] Figure 8 -APAA subarray.

[0030] Figure 9 - Antenna panel.

[0031] Figure 10 -APAA single block.

[0032] Figure 11 - The placement of SCs during their cluster launch.

[0033] Figure 12A , Figure 12B - A view of the ground portion of an image or ground control complex used for data reception and processing. Detailed Implementation

[0034] The embodiments of the present invention are based on the following provisions.

[0035] Preferably, the ERS SS includes at least one SC, as well as a ground control complex and an image ground portion for data reception and processing, which can be combined in one complex.

[0036] In addition, such as Figure 1 As shown, an ERS SS may include one or more spacecraft (1), a combination of fixed X and S band antennas (2), a control and processing center (3), a mobile control complex (4), and a mobile receiving complex (5).

[0037] The combination of devices within a complex, or the implementation of their mobile versions, depends on the conditions and objectives of the set task.

[0038] Spacecraft Figure 2A, 2B It is built on a dynamic frame of carbon and / or aluminum trusses. The invariance of the dimensional combination of structural elements allows for the provision of the required strength. At the same time, along with the required stiffness, it ensures a small mass of the structure.

[0039] Spacecraft Figure 3 , 5 6) It is constructed using a deployable solar array and a deployable radar payload.

[0040] Solar array and radar payload structure ( Figure 4A , 4B It is driven and locked in place to provide structural rigidity and minimum settling time after pointing maneuver.

[0041] The spacecraft uses a radar payload, which is constructed using a planar active phased array antenna (APAA) in the C-band (5250-5570 MHz, wavelength 554 cm). The APAA consists of three mechanical panels to reduce the size of the spacecraft in the transport configuration. Figure 7 ).

[0042] APAA consists of 15 identical subarrays, each of which is an independent radio-electronic device. Figure 8 Three central subarrays control the remaining subarrays, collect data from all subarrays, filter and compress the data, and store the imaging results in memory units (MUs). This design makes it easy to scale the APAA when calculating operations in different orbits, or to easily obtain radar images with better radio measurement sensitivity levels.

[0043] therefore, Figure 8 The following components are shown: antenna panel (6), azimuth combiner (7), phase shifter and attenuator board (7 channels) (8), azimuth splitter / multiplier (7 per channel) (9), external digital interface (10), antenna panel controller (11), high power amplifier (7 channels).

[0044] In specific cases, structurally, each subarray can consist of a control device—an FPGA with 8-channel ADC / DAC, 6 identical antenna panels, redundant power supply circuitry, digital control and synchronization lines, and digital signal lines. The antenna panel is an independent radio-electronic device containing 7 lines, each with 16 transceiver transmitters, manufactured using microstrip technology. Figure 9The spacing between the transceiver transmitters is 23 mm, less than half the wavelength, which reduces the sidelobe level of the antenna radiation. Each antenna panel contains an upconverter, a 7-channel signal splitter, a 7-channel controlled phase shifter, a preamplifier, an attenuator, a power amplifier in the transmit path; a circulator for switching the circuit from transmit to receive; a 7-channel controlled phase shifter, a low-noise amplifier, a downconverter, and a signal adder in the receive path. The amplifiers use gallium nitride transistors, which have higher efficiency, greater radiation resistance, and a wider temperature range compared to gallium arsenide and silicon transistors. The radar operates in pulse mode with a duty cycle of 4 to 30; therefore, high-capacity ionistors (supercapacitors) are used in the power amplifier stage to eliminate voltage and current surges during pulse transmission.

[0045] Antenna panels are paired to form phase centers, with each subarray having three phase centers. Each phase center has its own ADC / DAC line. The FPGA used in the control device with an 8-channel ADC / DAC utilizes only 3 channels in the subarrays used for signals; one channel is allocated to the calibration circuitry, and the remaining 4 channels can be used to serve the calibration circuitry of the phase centers and adjacent subarrays. In this configuration, the FPGAs in adjacent subarrays can be shut down and used in a "cold" backup mode, significantly increasing the reliability of APAA and the overall system.

[0046] To improve radiation resistance, the electronic components mounted on the back of the APAA in a flat design are protected by an aluminum plate, the thickness of which is increased for the control equipment section.

[0047] In this version, the APAA consists of 45 phase centers, each with its own digital and analog signal circuitry. For added reliability, all antenna panels in the subarray can be used as a single phase center, which would require 15 signal lines. This solution allows for the use of 2-3 operational control devices (including one of the three central control devices) to ensure system operability with a slight reduction in functionality.

[0048] Constructing an APAA as a digital antenna array increases the overall reliability of the system by using digital beamforming for both transmission and reception. For example, it is possible to obtain three beams with different deflection angles during reception, while simultaneously digitally adding signals from phase centers with different delays. In a conventional implementation, this would require three parallel analog lines and three times the number of ADCs.

[0049] The SC features an attitude and orbit control system that allows for both left and right-side imaging, significantly increasing the observation range and enabling a 90° yaw rotation for detailed imaging. Yawing the SC by 90° allows for a scan angle of ±25° azimuth without mechanically rotating the SC to track the imaging area, whereas in classic versions of modern SAR, the azimuth scan angle is ±2°. This allows for a significant increase in the synthetic aperture length, improved azimuth resolution, and enhanced radio measurement sensitivity through azimuth signal accumulation.

[0050] As airborne equipment for transmitting mission data via a radio link, a solution is used that includes an encoder-modulator and two APAA monoliths with narrow beams in the X-band. Figure 10 ).

[0051] To increase the reliability and efficiency of the mission data downlink, the spacecraft uses two arrays mounted on the left and right sides of the SC relative to the longitudinal axis of the radar payload. This solution enables direct downlink mode (simultaneous imaging and image downlink to the receiving station) at rates up to 1.5 Gbps via electronic scanning alone, without any mechanical guidance or drive. This electronic scanning can be performed in all directions in sectors at ±70 degrees to the normal, on both the left and right sides of the SC.

[0052] The device also uses dynamic modulation, and the modulation index is automatically selected by the control system based on the estimated relative distance to the receiving station. When using a small-aperture antenna as part of an Earth receiving station, this provides up to a 2x increase in the amount of raw downstream downlink. Due to the materials used in the design of the propulsion frame, the resulting spacecraft mass and size parameters allow it to be positioned below the launch vehicle fairing (e.g., below the fairing of the Soyuz 2.1 launch vehicle). Figure 11 It can place up to three vehicles and perform simultaneous cluster launches.

[0053] The ERS SC ground control complex (GCC) uses a robotic-based antenna-rotation complex constructed according to a hexapod scheme, with a minimum mirror diameter of 2.4m ÷ 3 and a small size parameter of 5m, and operates in both S-band and X-band.

[0054] GCC uses a radio modem with forward and reverse channels, which has high operating and technical parameters and minimal power consumption.

[0055] The Image Ground Component (IGS DRP) used for data reception and processing also employs a robotic-based antenna receiving device constructed according to a hexapod scheme, with a minimum mirror diameter of 2.4m ÷ 4.0m and small mass and size parameters, operating in both S-band and X-band.

[0056] In a preferred embodiment, IGS DRP is built on an automated workstation (AWS) that operates using open-source software based on Windows OS and optionally Astra Linux OS.

[0057] The IGS DRP is constructed using a demodulator that operates in adaptive mode with respect to modulation type depending on elevation angle, providing rates from 480 Mbps to 1.5 Gbps. The demodulator is equipped with a raw demapper that allows demodulation of signals with arbitrary modulation types. Signal constellation setup can be performed by the operator. The demodulator implements hardware decoding of error correction codes and removes radio link transmission protocols at the receive rate.

[0058] To improve reliability and uptime, and to operate under wind load conditions, the antenna system is equipped with radio-transparent shielding, such as... Figure 12A , Figure 12B It can be seen in the image.

[0059] To ensure maximum total daily time for communication sessions with spacecraft, GCC ground stations and IGS DRP receiving stations are geographically distributed / placed in non-serviceable containers, operate in automated mode, and are controlled from a single central location.

[0060] The GCC and IGS DRP architecture comprises a complex of dedicated software (SSW) that can operate in two modes (automatic and manual). Automatic mode allows the ground complex to function with minimal operator intervention. Manual mode allows individual use of each part of the SSW complex.

[0061] GCC uses a radio modem with forward and reverse channels, which has high operating and technical parameters and minimal power consumption.

[0062] The Image Ground Component (IGS DRP) used for data reception and processing also employs a robotic-based antenna receiving device constructed according to a hexapod scheme, with a minimum mirror diameter of 2.4m-4.0m and small mass and size parameters, operating in both S-band and X-band.

[0063] In a preferred embodiment, the IGS DRP is built on an automated workstation (AWS) that operates using Windows OS and optionally Astra Linux OS.

[0064] The IGS DRP is constructed using a demodulator that operates in adaptive mode with respect to modulation type depending on elevation angle, providing rates from 480 Mbps to 1.5 Gbps. The demodulator is equipped with a raw demapper that allows demodulation of signals with arbitrary modulation types. Signal constellation setup can be performed by the operator. The demodulator implements hardware decoding of error correction codes and removes radio link transmission protocols at the receive rate.

[0065] To improve reliability and operating time, as well as to operate under wind load conditions, the antenna system is equipped with a radome, such as... Figure 12A , Figure 12B It can be seen in the image.

[0066] To ensure maximum total daily time for communication sessions with spacecraft, GCC ground stations and IGS DRP receiving stations are geographically distributed / placed in non-serviceable containers, operate in automated mode, and are controlled from a single central location.

[0067] The GCC and IGS DRP architecture comprises a complex of dedicated software (SSW) that can operate in two modes (automatic and manual). Automatic mode allows the ground complex to function with minimal operator intervention. Manual mode allows individual use of each part of the SSW complex.

[0068] Implement the following functions in the complex of GCC and IGS DRP SSW: - Plan the imaging of objects around the world and transmit the program along with the selected mission packets from the GCC (MCC) to the SC; - Issue voice notifications to operators regarding system events and errors; - Utilize the complete telemetry of equipment and subsystems to generate, display, and analyze reports on ongoing communication sessions; - Real-time display of complete telemetry for the antenna receiver complex (ARC) and demodulator (modem); - Collect and analyze diagnostic data about the status of IGS DRP components before and during communication sessions; - Displays key information about all components of IGS DRP.

[0069] The GCC SSW implements a flexible system for scheduling communication sessions with the SC, supporting a large number of antenna receive complexes (ARCs). To enable operators to work efficiently, the GCC and IGS DRP SSW have a built-in system of electronic operation documentation, which takes the form of pop-up messages with brief information and links to detailed descriptions of operator actions.

[0070] In addition, GCC and IGS DRP SSW have a built-in electronic training system for operators of the IGS DRP Automated Workstation (AWS), which enables the following functions: - Familiarize yourself with and train to work with specific IGS DRP AWS SSW; - Testing is conducted to determine the material intake, qualifications, and appointment of AWS operators. GS and IGS DRP are built on remote technology to control the received information and transmit it to the data processing center via Ku (Ka) band wired or satellite communication channels.

[0071] Furthermore, the IGS DRP SSW features a built-in electronic processing system for radar images, optical images, and signals received from the AIS (Automatic Identification System). When images are acquired through secondary processing, neural network technology implemented on a hardware neural network module is used. The use of neural network technology enables the production of products with near real-time timescale subject processing, such as: integrated representation of radar and optical images; automatic identification of surface type and ice age; ship identification; and detection of “dark” ships even when the AIS signal transmitter is off.

[0072] Industrial applicability

[0073] In the announced decision, GCC and IGS DRP were established based on the principle of geographical distribution. Operation of the network of container non-serviceable stations is automatically controlled from a single data processing center.

[0074] The combined use of the above-mentioned technical solutions enables significant improvements in key parameters, achieves the aforementioned technical results, and further significantly reduces the cost of the space system in both the manufacturing and operational phases.

Claims

1. Earth remote sensing space system, including: - At least one spacecraft, built on a power frame of aluminum and / or carbon truss structure, is configured to be placed under the fairing of a launch vehicle; - The ground control complex is constructed using a robotic-mechanism-based antenna-rotation complex and operates in both the S-band and X-band. - The ground portion of the image used for data reception and processing is constructed using a robotic mechanism-based antenna receiving device, which is constructed according to a hexapod scheme and operates in both the S and X bands; -and included in the payload: - A synthetic aperture radar constructed using an active phased C-band antenna array is mounted on three mechanical panels and consists of 15 identical subarrays. These subarrays are independent radio-electronic devices, three of which are central subarrays. The central subarrays are able to control the remaining subarrays to collect data, filter and compress data, and store imaging results in a memory unit. - A medium-resolution optoelectronic camera in the visible and infrared frequency range; -AIS ship identification signal receiver; - Equipment for transmitting mission data includes an encoder-modulator and two active phased array monoliths with narrow beams in the X-band, mounted on the left and right sides of the spacecraft relative to the longitudinal axis of the radar payload, and providing an adaptive high-speed X-band radio link with rate control from 480 Mbps to 1.5 Gbps, wherein the modulation index is automatically selected by the control system based on the estimated relative distance to the data receiving station.

2. The space system of claim 1, wherein the ground control complex and the image ground portion for data reception and processing are located in a non-serviceable container, the container operating in an automated mode and controlled from a single data processing center.

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