Remote sensing constellation data transmission scheme design method based on data priority

Abstract

A remote sensing constellation data transmission scheme design method based on data priority belongs to the technical field of remote sensing satellites, and comprises the following steps: defining data priority according to various data use requirements, data volume and timeliness requirements of satellites of a remote sensing constellation, and adopting different downloading modes for data of different priorities; calculating the maximum data rate which can be generated by a single satellite by taking the satellite-ground link bandwidth and the inter-satellite link bandwidth as conditions; according to the maximum data rate, bandwidth allocation is carried out on the data with different priorities; and carrying out data transmission in a corresponding downloading mode according to the allocated bandwidth and the preset priority. According to the method, by grading the on-satellite data and limiting the output bandwidth for the data of different grades, real-time landing of core data, delayed landing of important data and landing of non-important data as required are ensured, and the problem that the bandwidth of a satellite-ground link and an inter-satellite link is not matched with the on-satellite data rate is solved.

Description

Technical Field

[0001] The invention relates to a remote sensing constellation data transmission scheme design method based on data priority, and belongs to the technical field of remote sensing satellites. Background Art

[0002] As constellations continue to expand, the number of satellites continues to climb, with some communications satellites now numbering hundreds. For remote sensing constellations, data from the entire constellation must be downlinked via satellite-to-ground links. However, ground stations can only be deployed in certain locations, limiting the number of satellites that can establish links with ground stations. Consequently, data from dozens of satellites must be routed through two or three satellites, severely congesting the satellite-to-ground links. Furthermore, the pressure on intersatellite links is even greater. Whether using shortest path or traffic-balancing routing algorithms, the intersatellite links of the landing satellites must receive data from multiple satellites, placing the heaviest onboard traffic. As the size of remote sensing constellations' detectors and onboard computing power increases, the amount of data that satellites need to downlink is exploding, creating a significant mismatch between intersatellite and satellite-to-ground bandwidths. Therefore, a data transmission solution for large remote sensing constellations is needed. Summary of the Invention

[0003] The technical problem solved by the present invention is: to overcome the shortcomings of the existing technology and provide a remote sensing constellation data transmission scheme design method based on data priority. By classifying the on-board data and limiting the output bandwidth of data of different levels, it is ensured that the core data is delivered in real time, the important data is delivered with a delay, and the non-important data is delivered on demand, thereby solving the problem of mismatch between the bandwidth of the satellite-to-ground link and the inter-satellite link and the on-board data rate.

[0004] The technical solution of the present invention is: a method for designing a remote sensing constellation data transmission scheme based on data priority, comprising:

[0005] Data priorities are defined based on the usage requirements, data volume, and timeliness of each type of data from each satellite in the remote sensing constellation. Data of different priorities are downloaded in different ways.

[0006] Calculate the maximum data rate that a single satellite can generate based on the satellite-to-ground link bandwidth and the inter-satellite link bandwidth;

[0007] Allocating bandwidth to data of different priorities according to the maximum data rate;

[0008] Data is transmitted in the corresponding downlink mode according to the allocated bandwidth and preset priority.

[0009] Furthermore, the data priority includes three levels:

[0010] Level A: Real-time transmission of data with a delay of seconds to maintain the normal operation of the constellation and the execution of missions, including remote control telemetry data and product data;

[0011] Class B: Data that does not affect the normal operation of the constellation or the success of the mission, and is prioritized for transmission when bandwidth permits, including image data. This type of data is transmitted in real time, and if the link bandwidth is insufficient, it will be backlogged and have a delay of minutes.

[0012] Class C: Data that allows post-interpretation and is transmitted based on ground needs, with no timeliness requirements, including engineering cache data; this type of data is preferentially transmitted from satellite to ground, does not require real-time performance, and has a delay of hours.

[0013] Furthermore, the downloading method of each type of data is as follows:

[0014] Class A data does not require ground-based downlink instructions; it is downloaded immediately after being generated onboard.

[0015] For Class B and Class C data, data transmission instructions must be sent from the ground;

[0016] For Class B and Class C data that can be preset, the ground shall submit a data transmission plan one day in advance;

[0017] For randomly generated Class B and Class C data, the ground will make a data transmission plan based on real-time telemetry and current link margin.

[0018] Furthermore, the limitation of the satellite-to-ground link bandwidth includes single-satellite data rate×number of satellites in a constellation≤satellite-to-ground link bandwidth×number of satellite-to-ground links.

[0019] Furthermore, the limitation of the inter-satellite link bandwidth includes single-satellite data rate×the number of satellites in the inter-satellite link≤inter-satellite link bandwidth.

[0020] Furthermore, the maximum data rate that can be generated by the single satellite is

[0021] Furthermore, allocating bandwidth to data of different priorities includes:

[0022] The bandwidth of Class A data should not exceed the bandwidth of a single satellite. If this requirement is not met, the data should be re-screened to reduce the amount of Class A data, or the bandwidth of the inter-satellite link and the satellite-to-ground link should be increased to improve the bandwidth of a single satellite.

[0023] The total bandwidth of Class B and Class C data shall not exceed the bandwidth of a single satellite minus the bandwidth of Class A data;

[0024] Limit the bandwidth of Class B data by delay ratio;

[0025] After class B data bandwidth is specified, the remaining bandwidth is allocated to class C data.

[0026] Furthermore, the delay ratio=generated data rate / bandwidth data rate.

[0027] A computer-readable storage medium stores a computer program, wherein the computer program, when executed by a processor, implements the steps of the method for designing a remote sensing constellation data transmission scheme based on data priority.

[0028] A device for designing a remote sensing constellation data transmission scheme based on data priority includes a memory, a processor, and a computer program stored in the memory and executable on the processor. The device is characterized in that when the processor executes the computer program, the steps of the method for designing a remote sensing constellation data transmission scheme based on data priority are implemented.

[0029] The advantages of the present invention compared with the prior art are:

[0030] The present invention discloses a data transmission solution for the downlink of massive data from remote sensing constellations. This solution overcomes the indiscriminate downlink of all traditional constellation data, regardless of priority. By classifying onboard data and limiting the output bandwidth for data of different levels, it ensures that core data is delivered in real time, important data is delivered with a delay, and non-important data is delivered on demand. A method for calculating the bandwidth of data of various priority levels is also provided, which contributes to the overall design of data transmission in the constellation space segment. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Various other advantages and benefits will become apparent to those skilled in the art upon reading the detailed description of the preferred embodiment below. The accompanying drawings are for illustration purposes only and are not to be considered as limiting the present invention. The same reference symbols are used throughout the drawings to represent the same components. In the drawings:

[0032] Figure 1 This is a schematic diagram of A / B level data of the present invention. DETAILED DESCRIPTION

[0033] In order to better understand the above technical solution, the technical solution of the present invention is described in detail below with reference to the accompanying drawings and specific embodiments. It should be understood that the embodiments of the present invention and the specific features in the embodiments are detailed descriptions of the technical solution of the present invention, rather than limitations on the technical solution of the present invention. In the absence of conflict, the embodiments of the present invention and the technical features in the embodiments can be combined with each other.

[0034] The following is a further detailed description of the remote sensing constellation data transmission scheme design method based on data priority provided by the embodiment of the present invention in conjunction with the accompanying drawings. Figure 1 , specific implementation methods may include:

[0035] Step 1: Satellite data classification

[0036] like Figure 1 As shown in the figure, based on the usage requirements of various types of satellite data, data volume, timeliness requirements and other factors, data priorities are defined as A, B, C (or multiple levels), with the following meanings:

[0037] A: Class A data is data necessary to maintain the normal operation of the constellation and execute missions, such as remote control, telemetry, and product data. This type of data must be transmitted in real time with a latency of seconds.

[0038] B: Data that does not affect the normal operation of the constellation or the success of the mission and is prioritized for transmission when bandwidth permits, such as image data. This type of data is prioritized for real-time transmission and may be backlogged or delayed by minutes when link bandwidth is insufficient.

[0039] C: Data that can be interpreted later, transmitted based on ground needs, and has no significant timeliness requirements is classified as C, such as engineering cache data. This type of data is prioritized for satellite-to-ground transmission and does not require real-time performance, with a latency of hours.

[0040] Each type of data has a pre-set default priority, and the data priority can be modified as needed while in orbit.

[0041] As shown in Table 1, the downloading methods of various types of data are as follows:

[0042] 1) Class A data does not require ground-based downlink instructions; it is automatically downlinked after being generated onboard.

[0043] 2) BC-level data requires data transmission instructions to be sent down from the ground.

[0044] ① For BC-level data that can be predicted in advance, the ground shall submit a data transmission plan one day in advance;

[0045] ②For randomly generated BC-level data, the ground will make a data transmission plan based on real-time telemetry and current link margin.

[0046] Table 1 Data classification table

[0047]

[0048] Step 2: Calculate the maximum real-time data rate of a single satellite

[0049] Calculate the maximum data rate that a single satellite can generate based on the satellite-to-ground link and inter-satellite link bandwidth. The real-time data rate on the satellite should meet the following requirements:

[0050] (1) Single satellite data rate × number of satellites in the constellation ≤ satellite-to-ground link bandwidth × number of satellite-to-ground links

[0051] The data rate of a single satellite multiplied by the number of satellites in the constellation is the real-time data rate generated by the entire constellation. If all this data is required to be delivered in real time, it should be less than the total bandwidth of the satellite-to-ground link, that is, the number of satellite-to-ground links multiplied by the bandwidth of a single link.

[0052] For example, if the satellite-to-ground link bandwidth is 2G and there are 4 links in total, the total satellite-to-ground link bandwidth is 8Gbps. If the number of satellites in the constellation is 40, the data rate generated by each satellite should be less than 200Mbps.

[0053] (2) Single satellite data rate × number of satellites in the intersatellite link ≤ intersatellite link bandwidth

[0054] The constellation data needs to be aggregated to the satellite that establishes a link with the ground station (referred to as the landing satellite). Therefore, the inter-satellite link of the landing satellite is the point with the largest load in the entire constellation. If the inter-satellite link is responsible for aggregating data from N satellites, then N×single-satellite data rate should be less than the inter-satellite link bandwidth.

[0055] For example, if the scenario involves a 6×6 Walker constellation with four deployed satellites, then due to the even distribution of the constellation and the assumption of a shortest path and traffic-balanced network routing algorithm, each deployed satellite needs to aggregate data from 36÷4-1=8 satellites. If a deployed satellite has two receiving intersatellite links, each intersatellite link must aggregate data from four satellites. If the intersatellite link bandwidth is 1 Gbps, the single-satellite data rate for each satellite should not exceed 250 Mbps.

[0056] (3) According to the satellite-to-ground bandwidth limit and the inter-satellite bandwidth limit, the maximum single-satellite data rate is calculated, that is,

[0057]

[0058] Step 3. Allocate bandwidth to each satellite based on data classification

[0059] After calculating the bandwidth of a single satellite using the calculation method in step 2, bandwidth allocation is performed for A / B / C level data. The requirements are as follows:

[0060] (1) Class A bandwidth ≤ single-satellite bandwidth. If this condition is not met, it means that Class A data cannot be delivered in real time. It is necessary to re-screen the data, reduce the amount of Class A data, or increase the inter-satellite link bandwidth and satellite-to-ground link bandwidth to improve the single-satellite bandwidth.

[0061] (2) B+C level data bandwidth ≤ single satellite bandwidth - A level bandwidth

[0062] (3) Limit the bandwidth of Class B data by delay ratio.

[0063] The delay ratio describes the transmission speed of the backlog data. The larger the delay ratio, the longer it takes for the backlog data to land. The formula for the delay transmission ratio is:

[0064] Delay ratio = generated data rate / bandwidth data rate

[0065] For example, assuming the B-level data bandwidth is 100 Mbps, and B-level data is generated at 300 Mbps for 10 seconds, it takes [300 Mbps*10s-100 Mbps*10s] / 100 Mbps+10s=30 seconds to complete the transmission of the backlog data. The delay transmission ratio is 30 / 10=3, meaning that 10 seconds of data requires three times the time to be transmitted. To meet the minute-level delay transmission of B-level data, the recommended delay ratio is ≤10.

[0066] (4) After the bandwidth for Class B data is specified, the remaining bandwidth is allocated to Class C data.

[0067] In the solution provided in the embodiment of the present invention, it is assumed that the constellation is a 6×6 Walker constellation, the number of satellite-to-ground links is 4, the satellite-to-ground link bandwidth is 5 Gbps, and each satellite is configured with 4 inter-satellite links, which are respectively linked to the 4 surrounding satellites. The inter-satellite link bandwidth is 1 Gbps.

[0068] Step 1: Classify the satellite data, assuming

[0069] Class A data satellite telemetry data and product data totaling 100Mbps;

[0070] Class B image data is 1Gbps;

[0071] C-level engineering data is the cache data of this planet.

[0072] Step 2: Calculate the maximum real-time data rate of a single satellite. Based on the above assumptions, we have

[0073] Single satellite bandwidth ≤ 4 × 5Gbps ÷ 36 = 555Mbps (limited by satellite-to-ground bandwidth)

[0074]

[0075] In summary, the bandwidth of a single satellite is 250Mbps.

[0076] Step 3. Allocate bandwidth to each satellite based on data classification

[0077] (1) Class A data rate 100Mbps≤250Mbps, to meet real-time requirements, allocate Class A data bandwidth 100Mbps.

[0078] (2) B+C data rate bandwidth ≤ 250-100Mbps = 150Mbps.

[0079] (3) Limit the bandwidth of Class B data by delay ratio.

[0080] It is known that the B-level image data is 1Gbps.

[0081] Delay ratio = generated data rate / bandwidth data rate

[0082] And the recommended delay ratio is ≤10, then the bandwidth data rate is ≥1Gbps / 10=100Mbps, and the Class B data bandwidth is 100Mbps.

[0083] (4) Class C data bandwidth is 150-100=50Mbps.

[0084] Conclusion: In the above hypothetical scenario, each satellite generates over 1Gbps of Class A and Class B data in real time, significantly exceeding the bandwidth of both inter-satellite and satellite-to-ground links. The data priority-based remote sensing constellation data transmission design specifies 100Mbps for Class A data, 100Mbps for Class B data, and 50Mbps for Class C data. This meets the bandwidth constraints of both satellite-to-ground and inter-satellite links, fulfills the real-time transmission requirements for Class A data, and the minute-delay transmission requirements for Class B data, making it an excellent data transmission design for this constellation.

[0085] The present invention provides a computer-readable storage medium, wherein the computer-readable storage medium stores computer instructions. When the computer instructions are executed on a computer, the computer is enabled to execute the method described above.

[0086] Those skilled in the art will appreciate that embodiments of the present invention may be provided as methods, systems, or computer program products. Thus, the present invention may take the form of an entirely hardware embodiment, an entirely software embodiment, or an embodiment combining software and hardware. Furthermore, the present invention may take the form of a computer program product implemented on one or more computer-usable storage media (including but not limited to magnetic disk storage and optical storage, etc.) containing computer-usable program code.

[0087] Obviously, those skilled in the art can make various changes and modifications to the present invention without departing from the spirit and scope of the present invention.

[0088] The present invention is intended to include these changes and modifications as long as they fall within the scope of equivalent technology.

[0089] The contents not described in detail in the specification of the present invention belong to the common knowledge of those skilled in the art.

Claims

1. A remote sensing constellation data transmission scheme design method based on data priority, characterized in that: include: Data priorities are defined based on the usage requirements, data volume, and timeliness of each type of data from each satellite in the remote sensing constellation. Data of different priorities are downloaded in different ways. Calculate the maximum data rate that a single satellite can generate based on the satellite-to-ground link bandwidth and the inter-satellite link bandwidth; Allocating bandwidth to data of different priorities according to the maximum data rate; Data is transmitted in the corresponding downlink mode according to the allocated bandwidth and preset priority.

2. The method for designing a remote sensing constellation data transmission scheme based on data priority according to claim 1, characterized in that: The data priority includes three levels: Level A: Real-time transmission of data with a delay of seconds to maintain the normal operation of the constellation and the execution of missions, including remote control telemetry data and product data; Class B: Data that does not affect the normal operation of the constellation or the success of the mission, and is prioritized for transmission when bandwidth permits, including image data. This type of data is transmitted in real time, and if the link bandwidth is insufficient, it will be backlogged and have a delay of minutes. Class C: Data that allows post-interpretation and is transmitted based on ground needs, with no timeliness requirements, including engineering cache data; this type of data is preferentially transmitted from satellite to ground, does not require real-time performance, and has a delay of hours.

3. The method for designing a remote sensing constellation data transmission scheme based on data priority according to claim 2, characterized in that: The downloading methods of each type of data are as follows: Class A data does not require ground-based downlink instructions; it is downloaded immediately after being generated onboard. For Class B and Class C data, data transmission instructions must be sent from the ground; For Class B and Class C data that can be preset, the ground shall submit a data transmission plan one day in advance; For randomly generated Class B and Class C data, the ground will make a data transmission plan based on real-time telemetry and current link margin.

4. The method for designing a remote sensing constellation data transmission scheme based on data priority according to claim 1, characterized in that: The limitation of the satellite-to-ground link bandwidth includes single-satellite data rate×number of satellites in the constellation≤satellite-to-ground link bandwidth×number of satellite-to-ground links.

5. The method for designing a remote sensing constellation data transmission scheme based on data priority according to claim 1, characterized in that: The limitation of the inter-satellite link bandwidth includes single-satellite data rate×the number of satellites in the inter-satellite link≤inter-satellite link bandwidth.

6. The method for designing a remote sensing constellation data transmission scheme based on data priority according to claim 1, characterized in that: The maximum data rate that a single satellite can generate is 7. The method for designing a remote sensing constellation data transmission scheme based on data priority according to claim 1, characterized in that: The bandwidth allocation for data of different priorities includes: The bandwidth of Class A data should not exceed the bandwidth of a single satellite. If this requirement is not met, the data should be re-screened to reduce the amount of Class A data, or the bandwidth of the inter-satellite link and the satellite-to-ground link should be increased to improve the bandwidth of a single satellite. The total bandwidth of Class B and Class C data shall not exceed the bandwidth of a single satellite minus the bandwidth of Class A data; Limit the bandwidth of Class B data by delay ratio; After class B data bandwidth is specified, the remaining bandwidth is allocated to class C data.

8. The method for designing a remote sensing constellation data transmission scheme based on data priority according to claim 7, characterized in that: The delay ratio=generated data rate / bandwidth data rate.

9. A computer-readable storage medium storing a computer program, characterized in that: When the computer program is executed by a processor, the steps of the method according to any one of claims 1 to 8 are implemented.

10. A device for designing a remote sensing constellation data transmission scheme based on data priority, comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, characterized in that: When the processor executes the computer program, the steps of the method according to any one of claims 1 to 8 are implemented.

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