RU2753201C1 - Space complex for remote earth sensing with a highly detailed level of observation of ground objects - Google Patents

Abstract

FIELD: cosmonautics.

SUBSTANCE: invention relates to space technology, namely to space systems for optical-electronic remote Earth sensing. The space complex for remote Earth sensing is comprised of no less than one space vehicle, a ground control complex (GCC), a ground image receiving and processing complex (GIRPC). The space vehicle is comprised of an optical-electronic payload built according to the Korsch design with five optical elements, providing imaging in the panchromatic channel and in four bands of the multispectral channel (NIR, R, G, B), an information reception and conversion system, and an information transmission tool based on an active phased array with a narrowly directed beam in the X-band. The GCC and the GIRPC use an antenna receiving apparatus based on a robotic mechanism built according to the hexapod scheme, functioning in both S and X bands, and are configured to communicate with a unified processing center.

EFFECT: improvement in the design of the SV and improvement in the quality of survey.

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Description

Technology area

The claimed invention relates to the field of space technology, more specifically, to space systems for optical-electronic remote sensing of the Earth (ERS).

State of the art

In modern conditions of the development of digital information technologies in the remote sensing market, the most relevant changes for the better are the following basic quantitative indicators of the quality and performance of space systems:

- a significant reduction in the cost per square kilometer of space imagery;

- reducing the cost of manufacturing, launching and operating the ERS space system;

- reducing the cost of designing and manufacturing a spacecraft;

- creation of a universal space platform for spacecraft, which allows to manufacture spacecraft on its basis with optical-electronic payloads of different resolution;

- reduction of the mass-dimensional characteristics of the spacecraft;

- the possibility of carrying out a group launch of ERS spacecraft;

- an increase in the spatial and linear resolution of images of space survey products without a significant increase in the mass of the spacecraft;

- increasing the frequency of filming the territory of interest by increasing the maneuverability of the spacecraft (SC), as well as by quickly and efficiently creating a constellation of spacecraft;

- increasing the performance of the space system by using the latest optoelectronic converters as part of the target electronic equipment, capable of providing shooting for a longer time on the orbit without heating the equipment and degrading the quality of images;

- increasing the rate of transmission of target information to ground receiving points by using highly directional onboard antennas with electronic beam scanning and using dynamic signal modulation schemes;

- reducing the cost of operating ground-based reception and control complexes by creating a network of universal combined in radio frequency bands (reception in the X-band, reception / transmission in the S-frequency band) container unattended stations, automatically controlled from a single center.

- the use of modern digital technologies for effective planning of the use of target equipment of spacecraft KS ERS in order to optimize the survey, taking into account the priorities, efficiency, as well as weather conditions and seasonality.

Various known solutions offer a solution to any of the listed aspects or a number of aspects. A detailed description of all known from the prior art solutions, similar to the proposed invention, in the framework of this application does not seem appropriate.

At the same time, you should indicate a decision that can be taken as the closest analogue of the proposed invention in terms of purpose and a number of coinciding features.

Namely, a space complex for remote sensing of the Earth of a highly detailed level of observation of terrestrial objects is known, disclosed in patent document RU 2460136 C2, 27.08.2012 [1].

The known solution includes a spacecraft, a ground-based complex for receiving and processing images, combined with a control complex.

The ground control complex in the solution known from [1] uses an antenna-rotary robotic complex operating in the S- and X-bands. The ground-based complex for receiving and processing images (and control) is built on the basis of automated workstations, a high-speed demodulator allows demodulation of signals with an arbitrary type of modulation.

As part of the complex, the following functions are implemented: planning of survey objects and bookmarking a program on board the spacecraft, generation, display and analysis of reports on communication sessions with complete equipment telemetry, real-time display of complete telemetry of antenna-receiving complexes and demodulators, collection and analysis of diagnostic data on condition of components, display of critical information, work in automatic and manual modes.

The disadvantages of the known solution include a weak constructive and functional study of space placement means, while these means are key in achieving the quality of the survey and the stability of the complex as a whole.

The problem solved by the proposed invention is the simultaneous fulfillment of all of the above modern system requirements for ERS space complexes by implementing the proposed approaches to the construction of spacecraft and ground-based reception, processing and control complexes.

The technical results achieved by the proposed invention will be indicated in the following sections of the description both explicitly and will follow for a specialist from the description of the design and operation of the components of the complex.

Disclosure of invention

As an object of the invention, a space complex for remote sensing of the Earth of a highly detailed level of observation of ground objects is considered, designed and manufactured taking into account the complex application of a number of technical and structural solutions that can significantly improve the main indicators of classical remote sensing systems.

According to the invention, in its preferred embodiment, a space complex for Earth remote sensing of a highly detailed level of observation of ground objects is proposed, including at least one spacecraft, as well as a ground control complex, a ground complex for receiving and processing images, while the spacecraft (SC) is built on a six-sided power frame made of aluminum or carbon truss structures and contains: four solar panels connected to the frame, made with the possibility of fixing in the working position with an angle of inclination of 45 ° to the longitudinal axis of the power frame using a drop-down bar; an optoelectronic payload, built according to the Korsch scheme with five optical elements, made with a constant ratio of the focal length F to the diameter of the entrance aperture d, F / d = 11.53, the indicated optoelectronic payload provides the formation of images of the earth's surface as in panchromatic channel and in four bands of a multispectral channel (NIR, R, G, B) and is equipped with a system for receiving and converting information based on the use of receivers with charging communication operating in the time delay and accumulation mode (CCD with VZN); means for transmitting target information based on an active phased array with a narrowly directed beam in the X-band, providing an adaptive high-speed radio link in the X-band with rate control from 480 Mbps to 1.5 Gbps, and the modulation index is automatically selected by the control system depending on calculated relative distance to the receiving station; an attitude control and stabilization system of the spacecraft, which allows for imaging with a reverse, and the ground control complex and the ground complex for receiving and processing images use an antenna-receiving device based on a robotic mechanism built according to the hexapod scheme with a minimum mirror diameter of 2.4 m ÷ 4, 0 operating in both S and X-bands, and are configured to communicate with a single data center via a wired or satellite Ku / Ka-band communication channel.

Additional embodiments, including those that are reflected in the dependent claims, are also presented within the scope of this description and are indicated below.

Within the framework of this description, it is not advisable to jointly group the technical results provided by the invention, since, as noted above, the invention provides a solution to many complex aspects. Therefore, for a clearer understanding of the essence of the invention, the corresponding results will be indicated below in the detailed description of the invention with a direct description of its essential features.

Implementation of the invention

For a more complete disclosure of the essence of the proposed invention is illustrated by the drawings, according to which are presented:

FIG. 1 - the composition of the remote sensing system.

FIG. 2 - Hexagonal platform with installed optoelectronic module and star sensors.

FIG. 3 is an image of the structure of the power hexagonal frame.

FIG. 4 is an image of the carbon base of solar cells.

FIG. 5 - view of the spacecraft with open solar panels.

FIG. 6 is a view of photovoltaic converters of solar cells.

FIG. 7 - Korsch optical scheme (5 mirrors).

FIG. 8 - telescope.

FIG. 9 - use of a spherical focal plane.

FIG. 10 - high-speed radio link based on AFAR.

FIG. 11-12 - spacecraft placement during their group launch.

FIG. 13 - view of the ground control complex or ground complex for receiving and processing images

The implementation of the invention is based on the following provisions.

The ERS CS includes at least one spacecraft, as well as a ground control complex, a ground complex for receiving and processing images, which can be conferred within one complex.

The spacecraft is built on a power hexagonal frame made of carbon or aluminum truss structures. In this case, depending on the diameter of the entrance aperture of the optical system (0.535 m; 0.750 m or 1.10 m), the frame differs in the length of the edge. The invariability of the combinations of the dimensions of the structural elements makes it possible to provide the required strength. At the same time, at the same time, with the required rigidity, a low weight of the structure is provided.

The spacecraft is built using solar panels, preferably with a carbon base as a skeleton, thus reducing the weight of the structure while meeting the required

rigidity. In particular, as shown in FIG. 5, the spacecraft uses four solar panels tilted at 45 ° to the longitudinal axis of the power frame in its design to optimize the spacecraft's moments of inertia and solar energy input.

The solar panels are driven and locked in position using a drop-down bar to ensure structural rigidity and minimal settling time after hover maneuvers. These solar panels are equipped with photovoltaic converters based on gallium arsenide (AsGa) material with three pn junctions, which can increase their efficiency by up to 30%.

The spacecraft uses an optoelectronic payload built according to the Korsh scheme (Fig. 7) with five optical elements with minimal dimensions and weight. The use of the Korsh scheme makes it possible to significantly reduce the size of the telescope and its weight.

The specified optoelectronic payload used in the spacecraft has three versions with a constant ratio of the focal length F to the diameter of the entrance aperture d, the number F / d = 11.53.

In particular cases of implementation, these parameters are selected from the following:

- the diameter of the entrance aperture of the optical system is 0.535 m, the focal length is F = 6.17 m;

- diameter of the entrance aperture of the optical system 0.75 m, focal length F = 8.65 m;

- diameter of the entrance aperture of the optical system 1.1 m, focal length F = 12.68 m.

The adopted ratio of the diameter of the entrance aperture and the focal length makes it possible to obtain the best value of the image quality indicators with the minimum weight and dimensions. The tests carried out show that for a telescope (Fig. 8) with an entrance diameter of 0.535 m, the telescope mass will be 125 kg, and the length at a focus of 6.17 m is only 1.8 m. a different telescope. It is possible to replace only the telescope, and the remaining payload units remain unchanged, having flight qualifications.

The optoelectronic payload is designed so that it provides the formation of images of the earth's surface both in the panchromatic channel (spectrum range) and in the four bands of the multispectral channel (NIR, R, G, B).

An optoelectronic payload with a system for receiving and converting information (SPID) is based on the use of receivers with a charging connection operating in a time delay and accumulation mode (CCD with VZN), namely:

- in a panchromatic channel with a changeable number of steps of accumulation from 8 to 128 steps, with an element size of the CCD matrix - 9x9 μm and a format of 1536 × 128 in the amount of 12 pieces, built in the focal plane in a line in a checkerboard pattern with an overlap of 80 elements between the CCDs for continuous formation of images during the rolls of the spacecraft with the provision of a shooting width of at least 12.5 km (the size of the frame capture on the ground);

- in a multispectral channel with 64 steps (NIR, R, G ranges) and 96 (B range) steps, with a CCD element size of 18x18 μm (binning up to 2x2 is used) and a 768x96 photozone format (one photozone) and 768 × 64 (three photo zones) in the amount of 12 pieces, built in the focal plane in a line in a checkerboard pattern with an overlap of 40 elements between the CCDs for continuous imaging when the spacecraft rolls with a shooting width of at least 12.5 km (size frame capture on the ground).

This construction of the SPPI allows obtaining the full amount of information in two channels, panchromatic and multispectral, while the composition of the SPPI remains unchanged for various types of optical systems.

At the same time, the arrangement of the panchromatic and multispectral channel matrices differs from the generally accepted one in that a spherical rather than a flat focal plane is used (Fig. 9), which significantly reduces image blur over the frame field when shooting in nadir and when shooting at various angles of roll and, accordingly , improves the quality of the picture.

An attitude control and stabilization system is provided in the spacecraft, which allows shooting with a reverse, which significantly increases the swath and allows you to shoot objects of much larger areas than in the prior art.

As a high-speed radio link for the transmission of target information, a solution based on an active phased array with a narrow beam in the X-frequency range is used. This solution allows the direct reset mode (simultaneous shooting and image reset to the receiving station) at speeds up to 1.5 Gbit / s without any mechanical guidance drives, only due to electronic scanning, which can be performed in a sector of ± 70 degrees from the normal in all directions.

Also, the device uses dynamic modulation, and the modulation index is automatically selected by the control system depending on the calculated relative range to the receiving station, which provides an increase in the volume of the raw stream discharge up to 2 times when using a small-aperture antenna as part of the Earth receiving station.

The spacecraft uses an adaptive high-speed X-band radio link with speed control from 480 Mbps to 1.5 Gbps with various types of electronic beam scanning (AFAR) modulation, with minimal dimensions and weight.

The weight and size characteristics of the spacecraft, due to the above-mentioned design, make it possible to place up to three spacecraft under the fairing of the launch vehicle (Figs. 11-12) and carry out a simultaneous group launch.

The ERS ground control complex (NKU) uses an antenna-rotary complex based on a robotic mechanism built according to a hexapod scheme with a minimum mirror diameter of 2.4m ÷ 3.5m and small-sized characteristics, operating in both S and X-bands.

The low-voltage switchboard uses a radio modem with a forward and reverse channel, which has high operational and technical parameters with minimal power consumption.

The ground-based complex for receiving and processing images (NKPOI) also uses an antenna-receiving device based on a robotic mechanism built according to a hexapod scheme with a minimum mirror diameter of 2.4 m ÷ 4.0 and small mass-dimensional characteristics, functions both in the S and X-ranges of lengths waves.

In preferred versions, NKPOI is built on the basis of automated workstations (AWS) operating using open source software based on WINDOWS OS, as well as based on Astra Linux OS (optional).

The NKPOI is built using a demodulator operating in an adaptive mode in terms of modulation types depending on the elevation angle, providing speeds from 480 Mbit / s to 1.5 Gbit / s. This demodulator is equipped with an original de-mapper that allows demodulating signals with arbitrary types of modulation. The constellation setting can be done by the operator. The demodulator implements hardware decoding of error-correcting codes and removal of the transport protocol of the radio link at the rate of reception.

To increase the reliability and operating time, as well as to work under wind loads, the antenna systems are equipped with a radio-transparent shelter, as can be seen in Fig. 13.

To ensure the maximum total daily time of communication sessions with spacecraft, the earth stations of the NKU and the receiving stations of the NKPOI are geographically distributed / located in unattended containers operating in an automatic mode and controlled from a single center.

The GCC and NKPOI include a complex of specialized software (SSS), which can operate in two modes (automatic and manual). Automatic mode allows the ground complex to function with minimal operator intervention. The manual mode allows you to use each of the parts of the SPO complex separately.

The complex SPO NKU and NKPOI implements the following functions:

- planning of survey objects around the globe and bookmarking of the program on board the spacecraft with the selected task package from the GCC (MCC);

- operator's voice notifications about system events and errors;

- formation, display and analysis of reports on the conducted communication sessions with complete telemetry of equipment and subsystems;

- real-time display of full telemetry of antenna receiving complexes (AIC) and demodulators (modems);

- collection and analysis of diagnostic data on the state of the NKPOI components before and during communication sessions;

- display of critical information about all the constituent parts of the NKPOI.

SPO NKU implements a flexible system for scheduling communication sessions with spacecraft, which supports a large number of antenna-receiving complexes (AIC). SPO NKU and NKPOI, for the effective work of operators, has a built-in system of electronic operational documentation in the form of pop-up messages with brief information and a link to a detailed description of the operator's actions.

Additionally, SPO NKU and NKPOI has a built-in electronic training system for operators of automated workstations (AWP) NKPOI, which implements the following functions:

- familiarization and training in working with open source software of a certain workstation of NKPOI;

- Carrying out tests to determine the assimilation of materials, qualifications and commissioning of AWP operators. ZS and NKPOI are built on the basis of remote control technology and transmission of the received information to the Data Processing Center through a wired or satellite communication channel of the Ku (Ka) -band.

In the stated decision, NKU and NKPOI are built on the principle of territorial distribution. From a single center, the operation of the network of container unattended stations is automatically controlled.

The combined use of the above-described technical solutions makes it possible to achieve a significant improvement in the main characteristics in comparison with classical ERS systems, with the achievement of the above technical results, and in addition, to significantly reduce the cost of the space system both at the manufacturing stage and at the operation stage.

Claims (4)

1. A space complex for remote sensing of the Earth of a highly detailed level of observation of ground objects, which includes: at least one spacecraft, as well as a ground control complex (GCC), a ground complex for receiving and processing images (NKPOI), while a space the apparatus (SC) is built on a power hexagonal frame made of aluminum or carbon truss structures and contains: four solar panels connected to the frame, made with the possibility of fixing in the working position with an angle of inclination of 45 ° to the longitudinal axis of the power frame using a drop-down bar; an optoelectronic payload, built according to the Korsch scheme with five optical elements, made with a constant ratio of the focal length F to the diameter of the entrance aperture d, F / d = 11.53, the indicated optoelectronic payload provides the formation of images of the earth's surface as in panchromatic channel and in four bands of a multispectral channel (NIR, R, G, B) and is equipped with a system for receiving and converting information based on the use of receivers with charging communication operating in the time delay and accumulation mode (CCD with VZN); means for transmitting target information based on an active phased array with a narrowly directed beam in the X-band, providing an adaptive high-speed radio link in the X-band with rate control from 480 Mbps to 1.5 Gbps, and the modulation index is automatically selected by the control system depending on calculated relative distance to the receiving station; an attitude control and stabilization system of the spacecraft, which allows for imaging with a reverse, and the ground control complex and the ground complex for receiving and processing images use in their composition an antenna-receiving device based on a robotic mechanism built according to the hexapod scheme with a minimum mirror diameter of 2.4 ÷ 4, 0 m, operating in both S and X-bands, and are made with the possibility of communicating with a single data processing center through a wired or satellite Ku / Ka-band communication channel. 2. The space complex according to claim 1, characterized in that the solar panels have a carbon base as a frame and are equipped with photovoltaic converters based on gallium arsenide (AsGa) material with three pn junctions. 3. The space complex according to claim 1, characterized in that the parameters d and F are selected from the following: d = 0.535 m, and F = 6.17 m or d = 0.75 m, and F = 8.65 m, or d = 1.1 m and F = 12.68 m. 4. The space complex according to claim 1, characterized in that the NKU and NKPOI stations are located in unattended containers operating in an automatic mode and controlled from a single data processing center.

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