Satellite operations

Abstract

A method for providing Earth observation data includes acquiring Earth observation echo data aboard a first satellite in low Earth orbit, determining a time required to transmit predetermined data from the first satellite to a ground station on Earth at the first satellite's current location. If the required time exceeds a predetermined threshold, the predetermined data may be transmitted to another satellite in orbit above the Earth using space-to-space radio communication. Alternatively, the first satellite may receive data related to the current location of another satellite in orbit above the Earth, determine a time required for the predetermined data to reach the ground station via the other satellite at the current location of at least one other satellite, and if the determined time for the other satellite is less than the determined time for the first satellite, transmit the predetermined data to the other satellite in orbit above the Earth using space-to-space radio communication. In some possible implementations, the echo data may be processed aboard the first satellite to generate an image and analyzed to determine a portion of interest. The predetermined data may then include a data structure including the location of the portion of interest that may be transmitted using a space-to-space link.

Description

Technical Field

[0001] The present invention relates to the processing and delivery of Earth observation satellite data products. Background Art

[0002] Many land and sea monitoring applications, such as the detection and tracking of ships, land vehicles, deforestation, and mining activities, require up-to-the-minute monitoring information to track events on Earth. To achieve this, Earth observation satellites can acquire monitoring images as they pass over the location of interest. However, the time required to return Earth observation data to Earth limits the freshness of the information provided to end users. This poses a problem for some monitoring applications that require up-to-the-minute information.

[0003] The embodiments described below are not limited to implementations that solve any or all of the disadvantages of the known approaches described above. Summary of the Invention

[0004] This Summary is provided to introduce some concepts in a simplified form that are further described below in the Detailed Description. This Summary is not intended to identify key features or essential features of the claimed subject matter, nor is it intended to be used to determine the scope of the claimed subject matter.

[0005] The present invention provides an earth observation satellite and a method for providing earth observation data, which can use a space-to-space link to transmit observation echo data.

[0006] In a first aspect, the present invention provides a method for providing Earth observation data, comprising: acquiring Earth observation echo data on a first satellite in low Earth orbit, and determining the time required to transmit predetermined data from the first satellite to a ground station on Earth at the current position of the first satellite.

[0007] If the required time exceeds a predetermined threshold, the predetermined data may be transmitted to another satellite in orbit above the Earth using space-to-space radio communication.

[0008] Alternatively, the first satellite may receive data related to the current position of another satellite in orbit above the Earth, determine a time required for predetermined data to reach a ground station via the other satellite at the current position of at least one other satellite, and if the determined time of the other satellite is less than the determined time of the first satellite, transmit the predetermined data to the other satellite in orbit above the Earth using space-to-space radio communication.

[0009] In a second aspect, the present invention provides an Earth observation satellite configured to implement any of the methods described herein. The satellite may include a sensor configured to collect echo data and a radio transmitter configured to transmit a portion of the echo data to another satellite using a space-to-space link.

[0010] In some possible implementations, the echo data may be processed onboard the first satellite. For example, the echo data may be processed to generate an image and analyzed to determine a portion of interest. The predetermined data may then include a data structure including a location of the portion of interest, which may be transmitted using a space-to-space link. Alternatively, the predetermined data may include at least a portion of the acquired echo data.

[0011] Also provided herein is a method for providing Earth observation data, comprising: acquiring Earth observation echo data at a satellite in orbit above the Earth, processing the echo data at the satellite to generate an image; analyzing the image at the satellite to determine a portion of interest; and transmitting a data structure including the location of the portion of interest to another satellite using a space-to-space link.

[0012] The methods described herein may be performed by software in a machine-readable form on a tangible storage medium, for example in the form of a computer program comprising computer program code means adapted to perform all the steps of any method described herein when the program is run on a computer and the computer program may be embodied on a computer-readable medium. Examples of tangible (or non-transitory) storage media include magnetic disks, USB sticks, memory cards, and the like, and do not include propagating signals. The software may be suitable for execution on a parallel processor or a serial processor, such that the method steps may be performed in any suitable order or simultaneously.

[0013] This invention recognizes that firmware and software can be valuable, separately tradable commodities. It is intended to cover software that runs on or controls "simple" or standard hardware to perform a desired function. It is also intended to cover software that "describes" or defines the configuration of hardware to perform a desired function, such as HDL (Hardware Description Language) software, such as used to design silicon chips or configure general-purpose programmable chips.

[0014] The features described below may be combined as appropriate, as will be apparent to those skilled in the art, and may be combined with any aspect of the invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Embodiments of the present invention are described by way of example with reference to the following drawings, in which:

[0016] Figure 1 Schematic diagram of the typical acquisition and transmission of Earth observation data to Earth.

[0017] Figure 2 Based on something similar to Figure 1 Schematic diagram of the method for near real-time acquisition and transmission of Earth observation data to the Earth.

[0018] Figure 3 is a schematic diagram of an example Earth observation satellite.

[0019] Figure 4 is a diagram of an example method for providing Earth observation data.

[0020] Figure 5 is a flow chart of an example method for providing Earth observation data.

[0021] Figure 6 is a flow chart of an alternative example method of providing Earth observation data.

[0022] Figure 7 is a schematic diagram of hardware used to implement the methods described herein.

[0023] The same reference numbers are used throughout the drawings to identify similar features. DETAILED DESCRIPTION

[0024] The following description of embodiments of the present invention is by way of example only. These examples represent the best modes currently known to applicants for putting the present invention into practice, although they are not the only modes for carrying out the present invention. This description sets forth the functions of the examples and the sequence of steps for constructing and operating the examples. However, the same or equivalent functions and sequences may be achieved using different examples.

[0025] Figure 1 and Figure 2 A typical Earth observation satellite 102 is shown in orbit 104 around Earth 106. In this document, the term "satellite" should be interpreted broadly to include all types of satellites, such as Earth observation satellites, communication satellites, and geostationary satellites, as well as space stations, spacecraft, and aircraft. In the following, some embodiments are described that use synthetic aperture radar or "SAR" to obtain imagery. Thus, Figure 1 The Earth observation satellite 102 is configured to acquire echo data when passing through a location 108 so as to image the location 108 and transmit the imaging data (e.g., raw echo data) to a ground station 110 on Earth 106. A computing system at the ground station can then process the imaging data in various ways, including using the data to generate an image of an area on Earth from space. Information derived from the raw data, such as an image, can then be transmitted to an end user. A single ground station 110 is shown in the figures, but in actual implementations, the Earth observation system may include multiple ground stations and multiple satellites. In some implementations, the raw data can be transmitted from the ground station to a cloud computing infrastructure, for example, and further processed in a cloud service.

[0026] Current satellite Earth observation methods cannot provide instantaneous response for detection services. The fastest possible time is achieved when ground station 110 can be used for "direct Earth transmission" of satellite 102, that is, when echo data is collected above the ground station's horizon, in other words, when satellite 102 can see ground station 110.

[0027] Typically, completing the "near real-time" acquisition and processing chain for urgent Earth observation data products takes 20-60 minutes. An example is ship detection, where satellite radar imagery is acquired to detect a vessel at sea, and this information is immediately needed to locate the vessel in question for interception. For example, the transmission of the raw echo data to Earth might take 5 minutes, processing it into an image at the ground station might take another 5 minutes, analyzing the image might take 10 minutes, and the various tasks of storing and uploading the resulting data to the client's system via the ground network might take another 15 minutes, for a total of 35 minutes.

[0028] More typically, there is a further delay while satellite 106 waits to pass by the first available ground station 110. Typical delays can be as long as 45 minutes or more before satellite 102 is within direct link range of ground station 110 and can transmit raw data downlink to Earth 106. Adding approximately 30 minutes of processing time on Earth, a 45-minute delay in transmission downlink means that the data will be 75 minutes late by the time it reaches the customer.

[0029] These situations are Figure 1 and Figure 2 In Figure 1 In FIG. 1 , satellite 102 can see ground station 110 and can transmit raw data related to position 108 to ground station 110 .

[0030] As mentioned above, it is unusual for a satellite to happen to pass by a ground station that can provide a downlink transmission immediately after acquiring the echo data. More likely, there will be some delay in reaching the orbital position where the ground station is in direct view. Figure 2 , where the satellite must travel some distance around the Earth to see the ground station.

[0031] In some cases, it may be economically justifiable to establish a ground station at a location immediately after data acquisition to provide direct-to-ground transmission, but this is typically only feasible when monitoring a fixed location on a regular basis. This is generally not a viable solution and would be inappropriate if the location changes or imagery of the new location is urgently needed. It is also unlikely to be suitable when the location of interest is offshore. Furthermore, satellite operators typically "rent" time at existing ground stations to communicate with their satellites. In other words, satellite operators do not have control over the location of the ground stations, and the number of ground stations available for downlinking data from satellites is limited.

[0032] Some methods described herein use space-to-space links to transmit Earth observation data to the ground. Prior to transmitting the data via the space-to-space link, a time required to transmit predetermined data from the satellite to a ground station on Earth can be determined. The predetermined data can include at least a portion of Earth observation echo data acquired by the satellite. Alternatively, as described further below, it can include a data structure derived from processing and analysis of the echo data on the satellite.

[0033] The time required for the transmission to Earth will include the time required for the satellite to come within the line of sight of the ground station. This can be determined from information available on the satellite, such as GPS sensor information and the ground station location.

[0034] The next step may depend on the space-to-space link being used. For example, if the data is being transmitted via a higher Earth orbit, it can be assumed that it will arrive faster than the predetermined time, so if the determined time exceeds the predetermined time, that data is used. Alternatively, as explained further below, the satellite may know the position of at least one other satellite. For example, satellites in the same constellation may share position information. In this case, the time of at least one other satellite can be determined, and if that time is shorter, that time can be used. It should be noted that the determined time of another satellite may allow for multiple space-to-space "hops."

[0035] Traditionally, little or no processing of raw data has been performed on satellites. Satellites are primarily designed for reliability and longevity. As a result, they are equipped with extremely powerful computing electronics at the expense of performance. Therefore, satellites are not equipped with the computing power to process raw data; all processing occurs at ground stations.

[0036] refer to Figure 3 An example Earth observation satellite 300, such as a synthetic aperture radar (SAR) satellite, can be used in various approaches. Some embodiments of the present invention use processing of the raw data at the satellite in conjunction with one or more space-to-space communication links to increase the speed with which information derived from the raw data can be delivered to a user.

[0037] As shown, satellite 300 includes a sensor 302 configured to collect echo data, a computing system 304 configured to process the echo data to generate an image and analyze the image to determine a portion of interest, and a transmitter 306 configured to transmit a data structure including the location of the portion of interest using a space-to-space link. A space-to-space link is a communication link between two transmitting satellites, as defined above. Sensor 302 may include one or more radar or optical transceivers for collecting echo data reflected from the Earth, and may be mounted on or housed within one or both of two generally planar structures 308 of satellite 300. Generally planar structures 308 are referred to in the art as "wings," but it should be understood that wings 308 of satellite 300 do not have the same aerodynamic performance requirements as, for example, aircraft wings. Computing system 304 includes a processor for processing the echo data and performing image analysis, as well as a memory storing instructions for the processor. Transmitter 306 may include a radio transmitter for transmitting the data structure using radio signals to another satellite, such as a telecommunications satellite, or another spacecraft, such as a space station. Computing system 304 and transmitter 306 may be mounted on or housed within satellite body 310 that extends from wings 308. In another example, transmitter 306 may be mounted on or housed within one or more of wings 308.

[0038] Thus, instead of transmitting raw data or information derived from image processing directly to a ground station, a satellite according to some embodiments can instead transmit to another satellite that may be in sight of the ground station, or closer to being able to transmit the information down to the ground station. The other satellites can be in the same or similar orbit, such as a low Earth orbit. Alternatively, the other satellites can be in a higher Earth orbit. The system can be used for communication between satellites, including terminals for data links on small satellites such as Iridium or Inmarsat's medium Earth orbit satellite phone constellations. Hardware types used for software radio can be used for this purpose.

[0039] Satellite 300 may include various other components. For example, one or more solar panels may be mounted on or housed in one or more of wings 308 and / or body 310 to provide power to other components. At least one energy storage device, such as a battery, may be mounted on or housed in one or more of wings 308 and / or body 310 to enable the satellite to operate in low-sun conditions. At least one transceiver for communicating with a ground station may be mounted on or housed in one or more of wings 308 and / or body 310, and / or transmitter 306 may be part of a transceiver configured to communicate with other satellites and ground stations. Satellite 300 may also include systems not further described herein, such as, but not limited to, a thermal control system, an attitude control system to ensure that satellite 300 is pointed in the correct direction, and a propulsion system.

[0040] Figure 4 Satellite 300 is shown in low Earth orbit 402. Satellite 300 may be used to acquire images of a location 404 on Earth, process the images onboard the satellite, and provide data derived from the images to Earth using a space-to-space link 406.

[0041] The raw echo data collected by the radar or optical sensor 302 of the satellite 300 is processed onboard the satellite 300 using a satellite computing system 304. The computing system 304 may suitably include a central processing unit (CPU) and / or a field programmable gate array (FPGA) for processing the raw echo data. The use of an FPGA can provide faster processing than a normal CPU processor. The echo data is processed to generate an image of the location 404 by using the timing of the echo signals received by the sensor 302 to map the contours of the Earth and objects on its surface.

[0042] The raw echo data collected by the radar or optical sensor 302 of the satellite 300 is processed onboard the satellite 300 by its computing system 304 to generate an image of the location 404 based on a profile determined using the time of the received echo signals. The satellite computing system 304 may include a central processing unit (CPU) and / or a field programmable gate array (FPGA) for processing the raw echo data.

[0043] The image can then be analyzed to determine portions of interest. The analysis operations are performed onboard satellite 300 by its computing system 304 and can be used to detect various objects or changes occurring on the Earth's surface that are of interest for monitoring applications.

[0044] For example, analysis operations may include detecting objects on the Earth's surface using an object detection algorithm, such as a neural network-based object detection algorithm. This may be useful in, for example, ship detection and / or tracking applications where ships need to be detected and / or identified. If a neural network is used, it may suitably include a classifier to classify objects into predefined classes. For example, a classifier may be used to classify a ship into a predefined type of ship. In this case, the neural network can be trained on the ground in a computationally intensive training process, but contextual data can be uploaded to satellite 300 to augment the dataset and / or add additional layers to the neural network. In this case, further training can be performed on the satellite using uploaded data, which may include data such as images of the ship, the ship's historical routes, and so on. In this or other cases, a threshold confidence level for the detection algorithm can be selected to ensure that, while some false positives may be detected, all true objects of interest are likely to be detected. In the case of object detection, the portion of the image of interest may include at least a portion of the detected object.

[0045] Additionally or alternatively, the analysis operation may include using a change detection algorithm to detect changes such as deforestation or changes caused by mining activity, or changes such as object movement. In an example, the change detection algorithm may be configured to detect changes using pixel mathematics. The change may be detected by reference to another image of the same location taken at a previous time, which may be taken by the same satellite 300 or a different satellite, and in some examples may be provided to the satellite 300 by uploading from a ground station or transmitting from another satellite. Alternatively or in addition, the change may be detected by reference to data derived from another such image, which may be taken by the same or a different satellite, and in some examples may be provided by transmitting from a ground station or another satellite. In the case of change detection, the portion of the image of interest may include at least a portion of an area on Earth that has undergone a change.

[0046] Object or change detection on satellite 300 may be facilitated by uploading additional information to satellite 300, such as water mask information defining coastlines and other bodies of water, such as rivers and lakes, land use classification information, such as boundaries between agricultural and urban areas or between state or private ownership, facility locations, parking lot boundaries, etc. For example, in the case of neural network-based object detection, such information may be utilized to provide more context.

[0047] Additionally or alternatively, the characteristics, type, or identity of the portion of interest can be performed onboard satellite 300. For example, in the case of object detection, satellite computing system 304 can be configured to detect object characteristics, such as the size of a vessel, object type, such as the type of vessel, or object identity, such as the unique identity of a vessel. This functionality can be appropriately provided by an object detection algorithm. In the case of change detection, computing system 304 can be configured to detect changing characteristics, such as deforestation rates, or types of changes, such as deforestation or mining.

[0048] Satellite computing system 304 can be configured to assemble a data structure for transmission. The data structure can include any of the location of the portion of interest, the characteristics, type, or identity of the portion of interest, and image segments that include at least a portion of the portion of interest. For example, in the case of object detection, the data structure can include any of the location of the detected object, the characteristics, type, or identity of the detected object, and image segments that include at least a portion of the object of interest. In this case, the segment can additionally include the immediate surroundings of the detected object. In the case of change detection, the data structure can include any of the location of the detected change area, the characteristics or type of the detected change, and image segments that include at least a portion of the change area. The location of the portion of interest can be described by coordinates, such as latitude and longitude coordinates. If more than one portion of interest is detected in the image, information related to each respective portion of interest can be included in the data structure.

[0049] Although segments including portions of interest may be included in the data structure, it should be understood that at least a majority of the image is not included in the data structure. As a result, the data structure can be significantly smaller than the image, for example, one or more orders of magnitude smaller than the image. This reduction in data size is useful for radio transmission.

[0050] The computing system 304 provides the data structure to a transmitter 306 of the satellite 300 for radar transmission via a space-to-space link. The data structure may be transmitted to another low-Earth orbit satellite, such as another Earth observation satellite, or any other suitable satellite, such as a communications satellite of a telecommunications network that may be in medium-Earth orbit. Figure 4 In the example shown, transmitter 306 transmits the data structure to a communication satellite 408 in medium Earth orbit for onward transmission to Earth using space-to-space link 406. Communication satellite 408 transmits the data structure to a ground station 412 on Earth via direct-to-Earth transmission 410. In other examples, the communication channel from satellite 300 to Earth can include two or more space-to-space links.

[0051] Space-to-space communication is useful when satellite 300 is ready to transmit a data structure but is not within direct link range of ground station 404. Traditionally, space-to-space data links are too slow to support the transmission of image data to Earth within a reasonable time frame. However, the reduced amount of data in the data structure according to some examples can facilitate space-to-space transmission because the amount of data can be reduced by one or more orders of magnitude. For example, the data structure can be three orders of magnitude smaller than the image. When satellite 300 is not within direct link range of a ground station, space-to-space communication enables the reduced data structure to be transmitted to Earth immediately or more quickly at a rate that achieves an acceptable transfer time. In an example, if the data structure is three orders of magnitude smaller than the image, the data structure can be transmitted to Earth using space-to-space communication in approximately 10 seconds. In this case, information contained in the data structure, such as the location and type of detected objects, can be transmitted to Earth and the end user without delay. In contrast, transmitting an image to Earth using space-to-space communication takes approximately two hours.

[0052] Satellite 300 can also be tasked using a space-to-space link, for example, using one or more satellites of a telecommunications network to command the satellite to acquire images of locations on Earth. The commands require minimal data, so this can be accomplished in a very reasonable amount of time. Using space-to-space communication to dispatch imaging satellite 300 and transmit the data structure to Earth makes the entire chain of events independent of direct access by the imaging satellite to a ground station. As a result, the delay between receiving an information request from an end user and delivering the information in the data structure to the end user is significantly reduced compared to conventional methods that rely on a direct link between the imaging satellite 300 and a ground station.

[0053] When satellite 300 is within direct link range of a ground station, the remaining image data not transmitted in the data structure can be transmitted down to Earth using a conventional direct link. This is useful for building an image archive for further analysis, such as providing context for object detection or change detection algorithms.

[0054] By providing multiple imaging satellites 300 in orbit, the delay between receiving an information request from an end user and delivering the information in the data structure to the end user can be further reduced, so that at any given time, there is not much waiting time before an available imaging satellite 300 passes over the location to be imaged. In this case, the request from the end user can be dispatched to an appropriate satellite 300 so that the location is imaged with minimal delay. This arrangement using multiple satellites 300 helps maintain consistently low latency.

[0055] refer to Figure 5, a satellite may perform method 500 to provide Earth observation data. Method 500 includes acquiring 502 Earth observation echo data and processing 504 the Earth observation echo data to generate an image. Method 500 also includes analyzing 506 the image to determine a portion of interest and transmitting 508 a data structure including the location of the portion of interest using a space-to-space link. The space-to-space link forms part of a communication channel to Earth.

[0056] The satellite can perform a series of operations to determine whether to use a space-to-space link to transmit information to a ground station. This can be used to transmit any data to a ground station and is not limited to the data structures described elsewhere herein. However, such operations are particularly useful for the transmission of such data structures.

[0057] A series of operations in Figure 6 . At operation 601, Earth observation data is acquired by a satellite in low Earth orbit. Then, at operation 603, a time T1 required to transmit predetermined data from the satellite to a ground station at the current position of the satellite is determined. The predetermined data may include a data structure described elsewhere herein, or may include at least a portion of the acquired echo data. The time determined at operation 603 may depend on the nature or amount of the predetermined data.

[0058] Then, in an optional series of operations, at 605, a determination is made as to whether time T1 exceeds a predetermined threshold. If so, predetermined data is automatically transmitted to another satellite using space-to-space radio communication. This other satellite may be a satellite known to the satellite acquiring the data and capable of transmitting data to Earth in a shorter time than T1. An example of such another satellite may be a satellite in a higher orbit that can see a larger area of ​​the Earth and is therefore more likely to be able to see a ground station.

[0059] The time T1 can be appropriately chosen to ensure that another, for example predetermined, satellite can transmit data down to the Earth in a shorter time than T1. In the case of a LEO constellation, a threshold can be determined based on knowledge of the constellation, so that as long as the threshold is appropriately chosen, another faster route to the ground will be available.

[0060] If T1 does not exceed the threshold, then at operation 600, the predetermined data is transmitted directly to the ground station, for example, once the satellite acquiring the echo data can see the ground station.

[0061] In an alternative sequence of operations between operations 605 and 607, at operation 611, the satellite acquiring the echo data may receive data related to the current position of another satellite in orbit above the Earth and determine the time T2 required to transmit the predetermined data downlink to a ground station via the other satellite at the other satellite's current position. The downlink transmission may be directly from the other satellite or via a third satellite. In other words, there is no limit to the number of space-to-space "hops" that can be used to transmit the data downlink to the ground station. At operation 615, a determination is made as to whether T2 is less than T1. If so, the data is transmitted to the other satellite using space-to-space radio communication. Otherwise, the process continues to operation 609. This sequence of operations does not utilize a threshold time for downlinking data to Earth, thus allowing for faster downlinking of data.

[0062] It should be understood that operations 611, 613, and 615 may be repeated for multiple other satellites and multiple space-to-space links before a decision is made to transmit predetermined data from the ground station. For example, operations 611, 613, and 615 may be repeated in this manner until a satellite acquiring Earth observation data reaches a position where it can see a ground station that is configured to receive data from the satellite or is capable of receiving data from the satellite.

[0063] Thus, in some implementations, a satellite that has acquired echo data can receive data related to the current positions of multiple other satellites in low Earth orbit and select a satellite to which to transmit data via a space-to-space link. This selection can be based on the current position, or the Earth-bound transmission times of multiple satellites can be determined and the fastest time can be selected.

[0064] Any of the methods described herein may include the additional step of determining whether a satellite acquiring the return data has sight of another satellite and / or is configured to communicate with another satellite that is in sight.

[0065] refer to Figure 7 , the satellite may include hardware 600 that performs method 500. Hardware 600 includes a communication module 602, an input device 604 such as a receiver, an output device 606 such as a transmitter, a processor 608, and memory 610. Memory 610 may store code encoding instructions that, when executed by processor 608, cause the satellite to perform method 500.

[0066] In the above embodiment, the server can include a single server or a server network. In some examples, the function of the server can be provided by a server network distributed across geographical regions, such as a global distributed server network, and the user can be connected to an appropriate server network based on the user's location.

[0067] For the sake of clarity, the above description discusses embodiments of the present invention with reference to a single user. It will be appreciated that in practice, the system may be shared by multiple users, and possibly a large number of users simultaneously.

[0068] The above embodiments are fully automatic. In some examples, a user or operator of the system may manually direct some steps of the method to be performed.

[0069] In the described embodiments of the present invention, the system can be implemented as any form of computing device and / or electronic device. Such a device may include one or more processors, which may be microprocessors, controllers, or any other suitable type of processor for processing computer-executable instructions to control the operation of the device in order to collect and record routing information. In some examples, such as where a system-on-chip architecture is used, the processor may include one or more fixed function blocks (also referred to as accelerators) that implement a portion of the method in hardware (rather than software or firmware). Platform software including an operating system or any other suitable platform software may be provided at the computing-based device to enable execution of application software on the device.

[0070] The various functions described herein can be implemented in hardware, software, or any combination thereof. If implemented in software, the functions can be stored on or transmitted on a computer-readable medium as one or more instructions or codes. Computer-readable media may include, for example, computer-readable storage media. Computer-readable storage media may include volatile or non-volatile, removable or non-removable media implemented in any method or technology for storing information such as computer-readable instructions, data structures, program modules, or other data. Computer-readable storage media can be any available storage medium that can be accessed by a computer. By way of example and not limitation, such computer-readable storage media may include RAM, ROM, EEPROM, flash memory or other memory devices, CD-ROM or other optical disk storage, magnetic disk storage or other magnetic storage devices, or any other medium that can be used to carry or store the required program code in the form of instructions or data structures and that can be accessed by a computer. The optical disks and magnetic disks used herein include compact discs (CDs), laser discs, optical disks, digital versatile discs (DVDs), floppy disks, and Blu-ray discs (BDs). In addition, propagation signals are not included within the scope of computer-readable storage media. Computer-readable media also include communication media, which include any media that facilitates the transfer of a computer program from one place to another. For example, a connection can be a communication medium. For example, if the software is transmitted from a website, server or other remote source using coaxial cable, fiber optic cable, twisted pair, DSL, or wireless technologies such as infrared, radio and microwave, it is included in the definition of communication media. Combinations of the above should also be included within the scope of computer-readable media.

[0071] Alternatively or in addition, the functions described herein may be at least partially performed by one or more hardware logic components. For example, but not limited to, the hardware logic components that may be used may include a field programmable gate array (FPGA), an application specific integrated circuit (ASIC), an application specific standard product (ASSP), a system on a chip (SOC), a complex programmable logic device (CPLD), etc.

[0072] Although illustrated as a single system, it should be understood that the computing device may be a distributed system. Thus, for example, several devices may communicate via a network connection and may jointly perform the tasks described as being performed by the computing device.

[0073] Although illustrated as a local device, it will be appreciated that the computing device may be remotely located and accessed via a network or other communication link (eg, using a communication interface).

[0074] As used herein, the term "computer" refers to any device having processing power such that it can execute instructions. Those skilled in the art will recognize that such processing power is incorporated into many different devices, and thus the term "computer" includes PCs, servers, mobile phones, personal digital assistants, and many other devices.

[0075] Those skilled in the art will recognize that the storage devices for storing program instructions can be distributed over a network. For example, a remote computer can store an example of a process described as software. A local or terminal computer can access the remote computer and download a portion or all of the software to run the program. Alternatively, the local computer can download software fragments as needed, or execute some software instructions at a local terminal and execute some software instructions at a remote computer (or computer network). Those skilled in the art will also recognize that, by utilizing conventional techniques known to those skilled in the art, all or part of the software instructions can be executed by a dedicated circuit such as a DSP, a programmable logic array, etc.

[0076] It should be understood that the benefits and advantages described above may relate to one embodiment, or may relate to several embodiments. The embodiments are not limited to those that solve any or all of the stated problems or have any or all of the stated benefits and advantages.

[0077] Any reference to "an" item refers to one or more of those items. The term "comprising" is used herein to mean including the identified method steps or elements, but such steps or elements do not comprise an exclusive list and the method or apparatus may include additional steps or elements.

[0078] As used herein, the terms "component" and "system" are intended to encompass computer-readable data storage configured with computer-executable instructions that, when executed by a processor, cause certain functions to be performed. Computer-executable instructions may include routines, functions, and the like. It should also be understood that a component or system may be located on a single device or distributed across several devices.

[0079] Furthermore, as used herein, the term "exemplary" is intended to mean "serving as an illustration or example of something."

[0080] Furthermore, to the extent that the term "includes" is used in either the detailed description or the claims, such term is intended to be inclusive in a manner similar to the term "comprising" as it is interpreted when used as a transitional term in a claim.

[0081] The accompanying drawings illustrate exemplary methods. Although the methods are shown and described as a series of actions performed in a particular order, it should be understood that the methods are not limited by the order of the sequence. For example, some actions may occur in an order different from the order described herein. In addition, an action may occur simultaneously with another action. Furthermore, in some cases, not all actions are required to implement the methods described herein.

[0082] Furthermore, the actions described herein may include computer-executable instructions that may be implemented by one or more processors and / or stored on one or more computer-readable media. Computer-executable instructions may include routines, subroutines, programs, execution threads, etc. Furthermore, the results of the method actions may be stored on a computer-readable medium, displayed on a display device, etc.

[0083] The order of the steps of the methods described herein is exemplary, but the steps may be performed in any suitable order, or simultaneously where appropriate. In addition, steps may be added or substituted in any method, or individual steps may be deleted from any method, without departing from the scope of the subject matter described herein. Aspects of any of the examples described above may be combined with aspects of any other example described to form additional examples without losing the intended effect.

[0084] It should be understood that the above description of the embodiments is given by way of example only, and that various modifications may be made by those skilled in the art. The foregoing description includes examples of one or more embodiments. Of course, it is not possible to describe every conceivable modification and variation of the above-described apparatus or method for the purposes of describing the aforementioned aspects, but those skilled in the art will recognize that many further modifications and permutations of various aspects are possible. Therefore, the described aspects are intended to encompass all such changes, modifications, and variations that fall within the scope of the appended claims.

Claims

1. A method for providing Earth observation data, comprising: acquiring Earth observation return data on a first satellite in low Earth orbit, wherein the return data includes radar return data, wherein the radar return data is obtained from a synthetic aperture radar system; processing the return data at the first satellite to generate an image; analyzing the image at the satellite to determine a portion of interest; determining a time required to transmit predetermined data from the first satellite down to a ground station on Earth at the current position of the first satellite, wherein the predetermined data includes at least a portion of Earth observation echo data acquired by the first satellite, wherein the portion of Earth observation echo data includes echo data from the portion of interest, or wherein the predetermined data comprises a data structure resulting from processing and analyzing the echo data, wherein the data structure comprises the position of the portion of interest; If the required time exceeds a predetermined threshold, the predetermined data is transmitted to another satellite in orbit above the Earth using a space-to-space radio communication link.

2. The method of claim 1, wherein the another satellite is in a medium Earth orbit or a higher Earth orbit.

3. The method of claim 1, wherein the another satellite is in low Earth orbit.

4. A method for providing Earth observation data, comprising: acquiring Earth observation return data on a first satellite in low Earth orbit, wherein the return data includes radar return data, wherein the radar return data is obtained from a synthetic aperture radar system; processing the return data at the first satellite to generate an image; analyzing the image at the satellite to determine a portion of interest; determining a time required to transmit predetermined data from the first satellite down to a ground station on Earth at the current position of the first satellite, wherein the predetermined data includes at least a portion of Earth observation echo data acquired by the first satellite, wherein the portion of Earth observation echo data includes echo data from the portion of interest, or wherein the predetermined data comprises a data structure resulting from processing and analyzing the echo data, wherein the data structure comprises the position of the portion of interest; receiving data relating to the current position of at least one other satellite in orbit above the Earth, determining a time required to transmit the predetermined data to a ground station via the at least one other satellite at the current position of the at least one other satellite, If the determined time of one of the other satellites is less than the determined time of the first satellite, the predetermined data is transmitted to the other satellite in orbit above the Earth using a space-to-space radio communication link.

5. The method according to claim 4, comprising: Data regarding current positions of a plurality of other satellites in low Earth orbit is received, and one of the plurality of other satellites is selected as a candidate for the transmission.

6. A method according to any of the preceding claims, wherein the data structure further comprises any of: a characteristic, type or identity of the portion of interest, and a fragment of an image comprising at least a portion of the portion of interest.

7. A method according to any one of the preceding claims, wherein the portion of interest comprises at least a portion of an object, and analysing the image comprises detecting the object using an object detection algorithm. The method of claim 7 , wherein the data structure comprises a property, type, or identity of the object.

9. A method according to claim 7 or 8, comprising classifying the object.

10. The method of claim 9, comprising classifying the object using a neural network.

11. A method according to any one of claims 7 to 10, wherein the object comprises a marine vessel.

12. The method of any one of claims 1 to 10, wherein the portion of interest comprises a region that has undergone a change, and analyzing the image comprises detecting the change using a change detection algorithm.

13. The method according to any one of claims 1 to 12, wherein the data structure comprises a segment of the image, the segment comprising at least a part of the portion of interest.

14. A method according to any one of claims 1 to 13, comprising transmitting further data of the image or further data derived therefrom using a direct ground station link.

15. An Earth observation satellite configured to implement the method according to any one of the preceding claims, the Earth observation satellite comprising: a sensor configured to collect the echo data; a computing system configured to process the echo data; A radio transmitter configured to transmit data to another satellite using a space-to-space link.

Images