A method for optimizing the installation location of quantum sources

Abstract

This invention discloses a method for optimizing the installation position of a quantum source. The method includes: setting a first position for the quantum source installed on the wing of a first aircraft, wherein the first position includes an initial angle between the first aircraft and a first object and an initial position of the quantum source on the wing; comparing the first position with several predetermined positions to obtain a first predetermined position to which the first position belongs; and based on the first predetermined position, obtaining a first qubit error rate and a first drift offset of the airborne quantum key distribution system corresponding to the first predetermined position. This invention solves the technical problem of low efficiency and security in airborne quantum key distribution systems due to boundary layer effects.

Description

Technical Field

[0001] This invention relates to the field of information optics, and more specifically, to a method for optimizing the installation location of a quantum source. Background Technology

[0002] Airborne quantum key distribution (QKD) technology, as an emerging secure communication solution, has significant application prospects and market demand. With the further development and maturation of quantum communication technology, it is believed that QKD will play an increasingly important role in the future, providing a higher level of security for communications. In the military, government, and commercial sectors, the need for secure communication is becoming increasingly urgent, especially in untrusted environments such as battlefields or hostile regions. Airborne quantum communication technology can meet these needs because it can provide real-time, highly secure communication and is not easily eavesdropped on or attacked. Compared to ground-based or satellite infrastructure, QKD offers greater flexibility and mobility. Airborne platforms can provide secure communication services anytime, anywhere, without relying on fixed infrastructure. Furthermore, airborne quantum communication systems can be rapidly deployed and withdrawn, making them ideal for responding to emergencies or temporary missions.

[0003] Currently, airborne quantum key distribution faces challenges posed by the boundary layer effect. The boundary layer, in fluid flow, refers to a layer of fluid near the surface of a solid object that exhibits distinct flow characteristics compared to the free flow region (the region away from the surface). These characteristics cause optical distortion in transmitted photons, leading to instability in the intensity and phase of the optical signal, ultimately affecting the performance of the quantum communication system. This results in photon loss and phase distortion, thus reducing the efficiency and security of quantum key distribution (QKD) systems. Therefore, traditional adaptive optics systems cannot accommodate the changing characteristics of the flow field due to the boundary layer effect, and there is currently no reliable solution to compensate for this effect. Besides optical compensation, optimizing the installation location of the quantum source is a feasible method to reduce the impact of the boundary layer effect. Summary of the Invention

[0004] This invention provides a method for optimizing the installation location of a quantum source, in order to at least solve the technical problem of low efficiency and security of airborne quantum key distribution systems due to boundary layer effects.

[0005] According to one aspect of the present invention, a method for optimizing the installation position of a quantum source is provided. The method may include: setting a first position for the quantum source installed on the wing of a first aircraft, wherein the first position includes an initial angle between the first aircraft and a first object and an initial position of the quantum source on the wing; comparing the first position with a plurality of predetermined positions to obtain a first predetermined position to which the first position belongs; based on the first predetermined position, obtaining a first qubit error rate and a first drift offset of an airborne quantum key distribution system corresponding to the first predetermined position; determining a target qubit error rate and a target drift offset based on the first qubit error rate and the first drift offset and a plurality of preset qubit error rates and drift offsets of the airborne quantum key distribution system; obtaining a target position among the plurality of predetermined positions based on the target qubit error rate and the target drift offset; and adjusting the quantum source from the first position to the target position.

[0006] Optionally, several predetermined positions are included: when the quantum source is installed on the wing of the first aircraft, any point at either end of the wing is taken as the origin, and the boundary of the wing is defined as the X-axis starting from the origin, and the X-axis is divided into several different distance intervals according to a set distance; when the first aircraft where the quantum source is located travels from the starting position to the ending position, the total zenith angle of the receiving telescope of the first object is obtained, and the total zenith angle is divided into several different angle intervals according to a predetermined angle; for each angle interval, each distance interval is changed to obtain several predetermined positions.

[0007] Optionally, comparing the first position with several predetermined positions to obtain the first predetermined position to which the first position belongs includes: comparing the initial angle in the first position with each angle interval in several predetermined positions to obtain the target angle interval; and comparing the initial position with each distance interval corresponding to the target angle interval to obtain the first predetermined position.

[0008] Optionally, before determining the target qubit error rate and target drift offset based on the first qubit error rate and the first drift offset and several preset qubit error rates and drift offsets of the airborne quantum key distribution system, the method further includes: obtaining several preset qubit error rates and drift offsets of the airborne quantum key distribution system based on several predetermined positions, wherein each predetermined position corresponds to one qubit error rate and drift offset.

[0009] Optionally, determining the target qubit error rate and target drift offset based on the first qubit error rate and the first drift offset and several preset qubit error rates and drift offsets of the airborne quantum key distribution system includes: comparing the first qubit error rate and the first drift offset with several preset qubit error rates and drift offsets one by one; if the first qubit error rate and the first drift offset are less than or equal to several preset qubit error rates and drift offsets, the first qubit error rate and the first drift offset are determined as the target qubit error rate and the target drift offset; if the first qubit error rate and the first drift offset are greater than several preset qubit error rates and drift offsets, the smallest qubit error rate and the smallest drift offset among several preset qubit error rates and drift offsets are determined as the target qubit error rate and the target drift offset.

[0010] The beneficial effects of this invention are:

[0011] This invention proposes a method for optimizing the installation position of a quantum source. First, the initial position of the quantum source is obtained. Then, the predetermined position within a set of predetermined positions is determined. These predetermined positions are defined as follows: when the quantum source is installed on the wing of a first aircraft, any point at either end of the wing is taken as the origin. Starting from the origin, the wing boundary is defined as the X-axis, and the X-axis is divided into several different distance intervals according to a predetermined distance. When the first aircraft, where the quantum source is located, travels from the starting position to the ending position, the total zenith angle of the receiving telescope of the first object is obtained. This total zenith angle is divided into several different angle intervals according to a predetermined angle. For each angle interval, each distance interval is changed to obtain several predetermined positions.

[0012] Based on the predetermined position, the first qubit error rate and first drift offset of the first position are obtained. These are then compared with several preset qubit error rates and drift offsets to obtain the target qubit error rate and target drift offset. The target qubit error rate and target drift offset are the minimum values ​​of these preset qubit error rates and drift offsets. The target position corresponding to the target qubit error rate and target drift offset is determined as the target position of the quantum source. This solves the technical problem of low efficiency and security in airborne quantum key distribution systems due to boundary layer effects. It achieves the technical effect of improving the efficiency and security of airborne quantum key distribution systems under boundary layer effects by changing the position of the quantum source. Attached Figure Description

[0013] The accompanying drawings, which are included to provide a further understanding of the invention and form part of this application, illustrate exemplary embodiments of the invention and, together with their description, serve to explain the invention and do not constitute an undue limitation thereof. In the drawings:

[0014] Figure 1 This is a flowchart of a control method for an aircraft wheel brake control system according to an embodiment of the present invention;

[0015] Figure 2 This is a schematic diagram illustrating how the bit error rate of a quantum bit varies with several predetermined positions in an air-to-ground link according to an embodiment of the present invention;

[0016] Figure 3 This is a schematic diagram illustrating how the drift offset changes with several predetermined positions in an air-to-ground link according to an embodiment of the present invention.

[0017] Figure 4 This is a schematic diagram illustrating how the bit error rate of a quantum bit varies with several predetermined positions in an air-to-air link according to an embodiment of the present invention;

[0018] Figure 5 This is a schematic diagram illustrating how the drift offset changes with several predetermined positions in an air-to-air link according to an embodiment of the present invention. Detailed Implementation

[0019] To enable those skilled in the art to better understand the present invention, the technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort should fall within the scope of protection of the present invention.

[0020] It should be noted that the terms "first," "second," etc., in the specification, claims, and accompanying drawings of this invention are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such terms can be used interchangeably where appropriate so that the embodiments of the invention described herein can be implemented in orders other than those illustrated or described herein. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover a non-exclusive inclusion; for example, a process, method, system, product, or apparatus that comprises a series of steps or units is not necessarily limited to those steps or units explicitly listed, but may include other steps or units not explicitly listed or inherent to such processes, methods, products, or apparatus.

[0021] Example 1

[0022] According to an embodiment of the present invention, a method for optimizing the installation location of a quantum source is provided. It should be noted that the steps shown in the flowchart in the accompanying drawings can be executed in a computer system containing at least one set of computer-executable instructions. Furthermore, although a logical order is shown in the flowchart, in some cases, the steps shown or described may be executed in a different order than that shown here.

[0023] Figure 1 This is a flowchart of a method for optimizing the installation location of a quantum source according to an embodiment of the present invention, such as... Figure 1 As shown, the method may include the following steps:

[0024] Step S101: Set the first position of the quantum source installed on the wing of the first aircraft, wherein the first position includes the initial angle between the first aircraft and the first object and the initial position of the quantum source on the wing.

[0025] In the technical solution provided by step S101 of the present invention, the first position of the quantum source installed on the wing of the first aircraft is obtained during the flight of the first aircraft. The first position includes the initial angle between the first aircraft and the first object and the initial position of the quantum source on the wing. The first object is the second aircraft or the ground station. In the air-to-ground link, the speed and altitude of the first aircraft are kept consistent during the flight. In the air-to-air link, the speed of the first aircraft and the second aircraft are the same and the direction is the same.

[0026] It should be noted that the first and second aircraft can be fixed-model drones. In this invention, there is airflow interference, or boundary layer, below the wings. During communication via the airborne quantum key distribution system, photons first pass through the boundary layer, then traverse a long-distance atmospheric channel, and finally reach the receiving telescope at the ground station. Due to the boundary layer effect, the boundary layer causes significant angular deviations in photons propagating through long-distance channels. This deviation causes photons to deviate from their original positions. Photons emitted by the light source radially pass through the boundary layer within the divergence angle range, exhibiting different propagation directions at different positions. The boundary layer refers to a layer of fluid near the surface of a solid object in fluid flow, exhibiting distinct flow characteristics compared to the free-flowing region (the region away from the object's surface). These characteristics cause optical distortion in the transmitted photons, leading to instability in the intensity and phase of the optical signal, ultimately affecting the performance of the quantum communication system.

[0027] Step S102: Compare the first position with several predetermined positions to obtain the first predetermined position to which the first position belongs.

[0028] In the technical solution provided by step S102 of the present invention, the first predetermined position corresponding to the first position is obtained by comparing the first initial position and initial angle with a number of initial positions and initial angles.

[0029] Step S103: Based on the first predetermined position, obtain the first qubit error rate and the first drift offset of the airborne quantum key distribution system corresponding to the first predetermined position.

[0030] In the technical solution provided by step S103 of the present invention, the first predetermined position is substituted into the MATLAB evaluation of the airborne quantum key distribution scenario to obtain the first qubit error rate and the first drift offset of the airborne quantum key distribution system. The parameters of the airborne quantum key distribution are shown in Table 1.

[0031] Table 1 Parameters for Airborne Quantum Key Distribution

[0032]

[0033]

[0034] Step S104: Based on the first qubit error rate and the first drift offset, and several preset qubit error rates and drift offsets of the airborne quantum key distribution system, determine the target qubit error rate and the target drift offset.

[0035] In the technical solution provided by step S104 of the present invention, the first qubit error rate and the first drift offset are compared with several preset qubit error rates and drift offsets of the airborne quantum key distribution system to obtain the target qubit error rate and the target drift offset.

[0036] Step S105: Based on the target qubit error rate and the target drift offset, obtain the target position among several predetermined positions.

[0037] In the technical solution provided by step S105 of the present invention, the target position corresponding to the target qubit error rate and the target drift offset is obtained based on the target qubit error rate and the target drift offset.

[0038] Step S106: Adjust the quantum source from the first position to the target position.

[0039] In the technical solution provided by step S106 of the present invention, if the target position of the quantum source is the first position, the first position is kept unchanged; if the target position of the quantum source is not the first position, the first position is adjusted to the target position.

[0040] The method described in this embodiment will be further described below.

[0041] As an optional embodiment, step S102, several predetermined positions, includes: when the quantum source is installed on the wing of the first aircraft, taking any point at either end of the wing as the origin, starting from the origin, defining the wing boundary as the X-axis, and dividing the X-axis into several different distance intervals according to a set distance; when the first aircraft where the quantum source is located travels from the starting position to the ending position, obtaining the total zenith angle of the receiving telescope of the first object, dividing the total zenith angle into several different angle intervals according to a predetermined angle; for each angle interval, changing each distance interval to obtain several predetermined positions.

[0042] In this embodiment, when the quantum source is installed on the wings of the first aircraft, any point at either end of the wing is taken as the origin. When the left end of the wing is taken as the origin, the wing boundary is defined as the X-axis, and the X-axis is divided into 50 equal parts to obtain 8 different distance intervals, such as 0~50, 50~100, ..., 350~400. When the airborne quantum key distribution is in an air-to-ground link or an air-to-air link, when the first aircraft travels from the starting position to the ending position, the total zenith angle of the receiving telescope of the first object is obtained. The total zenith angle is divided into 10° equal parts to obtain 16 different angle intervals, such as -80~-70, -70~-60, ..., 70~80. For example, the first angle interval is -80~-70. Based on the first angle interval, each distance interval corresponding to the first angle interval is obtained. For example, one of the several predetermined positions can be (-80~-70, 0~50), and the other predetermined positions are obtained according to this method.

[0043] As an optional embodiment, step S102, comparing the first position with several predetermined positions to obtain the first predetermined position to which the first position belongs, includes: comparing the initial angle in the first position with each angle interval in the several predetermined positions to obtain the target angle interval; and comparing the initial position with each distance interval corresponding to the target angle interval to obtain the first predetermined position.

[0044] In this embodiment, when the initial angle in the first position is 16 degrees, the initial angle is compared with each angle range in several predetermined positions to obtain the target angle range of 10 to 20. When the initial position is 236, and the target angle range is 10 to 20, the distance range of 236 is determined to be 200 to 250. Therefore, the first predetermined position is (200 to 250, 10 to 20).

[0045] As an optional embodiment, before determining the target qubit error rate and target drift offset based on the first qubit error rate and the first drift offset and several preset qubit error rates and drift offsets of the airborne quantum key distribution system, the method further includes: obtaining several preset qubit error rates and drift offsets of the airborne quantum key distribution system based on several predetermined positions, wherein each predetermined position corresponds to one qubit error rate and drift offset.

[0046] In this embodiment, several predetermined positions are substituted into the MATLAB evaluation scenario of airborne quantum key distribution to obtain several preset qubit error rates and drift offsets. When airborne quantum key distribution is in an air-to-ground link, this embodiment of the invention proposes a schematic diagram showing how the qubit error rate in the air-to-ground link changes with several predetermined positions. Figure 2 This is a schematic diagram illustrating the variation of the bit error rate of a quantum bit with several predetermined positions in an air-to-ground link according to an embodiment of the present invention, as shown below. Figure 2 As shown in the figure. This embodiment of the invention presents a schematic diagram illustrating how the drift offset in an air-to-ground link varies with several predetermined positions. Figure 3 This is a schematic diagram illustrating the variation of drift offset in an air-to-ground link with several predetermined positions according to an embodiment of the present invention, such as... Figure 3 As shown.

[0047] Depend on Figure 2 As we know, QBER stands for Quantum Bit Error Rate, position refers to each of several predetermined positions, and Azimuth Angle (rad) refers to each of several predetermined positions, which is the zenith angle in the first object. Figure 2 It can be seen that the bit error rate (QBER) of the qubits increases with the increase of the absolute value of the angle. When the absolute value of the angle is equal to 80°, the QBER stabilizes at 0.35 ± 0.05. Furthermore, the QBER remains consistent across different mounting positions and angles, indicating that the mounting position has a negligible impact on the system's QBER. It is noteworthy that the QBER only changes slightly with different mounting positions when the angle is equal to 80°. A slight increase in QBER occurs when the mounting position is at the center of the wing, while a slight decrease occurs when the mounting position is on either side. Figure 2 This indicates that the flow field at different installation locations has a relatively small impact on the bit error rate of qubits.

[0048] Depend on Figure 3As can be seen, Drifted Offset is the drift offset, position is each of several predetermined positions, and Azimuth Angle (rad) is each angle among several predetermined positions. The drift offset increases with the increase of the absolute value of the angle. When the absolute value of the angle is less than 70°, the deflection at each position is still relatively small because the path of the photon through the boundary layer is shorter, resulting in a smaller deflection angle. However, when the angle reaches -80° or 80°, the photon travels a longer distance in the boundary layer. Furthermore, positioning the quantum source at the midpoint of the wing maximizes the distance the photon travels within the boundary layer, thus producing a greater photon deflection.

[0049] When airborne quantum key distribution is in an air-to-air link, this embodiment of the invention presents a schematic diagram showing how the bit error rate of qubits in the air-to-air link varies with several predetermined positions. Figure 4 This is a schematic diagram illustrating the variation of the bit error rate of a quantum bit with several predetermined positions in an air-to-air link according to an embodiment of the present invention, as shown below. Figure 4 As shown in the diagram, this embodiment of the invention presents a schematic diagram illustrating how the drift offset in an air-to-air link varies with several predetermined positions. Figure 5 This is a schematic diagram illustrating how the drift offset changes with several predetermined positions in an air-to-air link according to an embodiment of the present invention, as shown below. Figure 5 As shown.

[0050] Depend on Figure 4 It can be seen that, depending on the installation location of the airborne quantum source, the qubit error rate of the quantum key distribution system does not change significantly across all angle ranges. When the zenith angle of the receiver telescope is 0°, the qubit error rate shows low values ​​at different locations. However, when the zenith angle of the receiver telescope is -80°, 70°, and 80°, the qubit error rate is higher at some locations. This may be due to the significant changes in refractive index in these specific regions, resulting in large differences in the optical path.

[0051] Depend on Figure 5 It is known that the drift offset varies with the different azimuth angles and positions of the randomly mounted quantum source. The offset is significantly smaller at a zenith angle of 0° than at other angles, mainly because the photon passes through the shortest boundary layer and experiences relatively less interference. When the zenith angle remains constant, mounting the light source in the center of the wing results in a larger deflection angle than on either side. To minimize photon offset in this case, it is recommended to mount the light source on either side of the wing. Furthermore, considering the need for the system to maintain a low qubit error rate, maintaining the smallest possible zenith angle in air-to-air scenarios is also important.

[0052] As an optional embodiment, step S104, determining the target qubit error rate and target drift offset based on the first qubit error rate and the first drift offset and several preset qubit error rates and drift offsets of the airborne quantum key distribution system, includes: comparing the first qubit error rate and the first drift offset with several preset qubit error rates and drift offsets one by one; when the first qubit error rate and the first drift offset are less than or equal to several preset qubit error rates and drift offsets, the first qubit error rate and the first drift offset are determined as the target qubit error rate and the target drift offset; when the first qubit error rate and the first drift offset are greater than several preset qubit error rates and drift offsets, the smallest qubit error rate and the smallest drift offset among several preset qubit error rates and drift offsets are determined as the target qubit error rate and the target drift offset.

[0053] In this embodiment, the first qubit error rate and the first drift offset are compared one by one with several preset qubit error rates and drift offsets. If the first qubit error rate and the first drift offset are both less than or equal to the several preset qubit error rates and drift offsets, the first qubit error rate and the first drift offset are determined as the target qubit error rate and the target drift offset. If the first qubit error rate and the first drift offset are greater than the several preset qubit error rates and drift offsets, the smallest qubit error rate and the smallest drift offset among the several preset qubit error rates and drift offsets are determined as the target qubit error rate and the target drift offset.

[0054] In this embodiment of the invention, a first position is set for a quantum source installed on the wing of a first aircraft. The first position includes an initial angle between the first aircraft and a first object, and an initial position of the quantum source on the wing. The first position is compared with several predetermined positions to obtain a first predetermined position to which the first position belongs. Based on the first predetermined position, a first qubit error rate and a first drift offset of the airborne quantum key distribution system corresponding to the first predetermined position are obtained. Based on the first qubit error rate and the first drift offset, and several preset qubit error rates and drift offsets of the airborne quantum key distribution system, a target qubit error rate and a target drift offset are determined. Based on the target qubit error rate and the target drift offset, a target position among several predetermined positions is obtained. The quantum source is adjusted from the first position to the target position. This solves the technical problem of low efficiency and security of the airborne quantum key distribution system due to boundary layer influence, achieving the technical effect of improving the efficiency and security of the airborne quantum key distribution system under boundary layer influence by changing the position of the quantum source.

[0055] The sequence numbers of the above embodiments of the present invention are for descriptive purposes only and do not represent the superiority or inferiority of the embodiments.

[0056] In the above embodiments of the present invention, the descriptions of each embodiment have different focuses. For parts not described in detail in a certain embodiment, please refer to the relevant descriptions of other embodiments.

[0057] In the several embodiments provided in this application, it should be understood that the disclosed technical content can be implemented in other ways. The device embodiments described above are merely illustrative; for example, the division of units can be a logical functional division, and in actual implementation, there may be other division methods. For example, multiple units or components may be combined or integrated into another system, or some features may be ignored or not executed. Furthermore, the displayed or discussed mutual couplings, direct couplings, or communication connections may be through some interfaces; indirect couplings or communication connections between units or modules may be electrical or other forms.

[0058] The units described as separate components may or may not be physically separate. The components shown as units may or may not be physical units; that is, they may be located in one place or distributed across multiple units. Some or all of the units can be selected to achieve the purpose of this embodiment according to actual needs.

[0059] Furthermore, the functional units in the various embodiments of the present invention can be integrated into a first processing unit, or each unit can exist physically separately, or two or more units can be integrated into one unit. The integrated unit can be implemented in hardware or as a software functional unit.

[0060] If the integrated unit is implemented as a software functional unit and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of the present invention, in essence, or the part that contributes to the prior art, or all or part of the technical solution, can be embodied in the form of a software product. This computer software product is stored in a storage medium and includes several instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) to execute all or part of the steps of the methods of the various embodiments of the present invention. The aforementioned storage medium includes various media capable of storing program code, such as USB flash drives, read-only memory (ROM), random access memory (RAM), portable hard drives, magnetic disks, or optical disks.

[0061] The above are merely preferred embodiments of the present invention. It should be noted that those skilled in the art can make various improvements and modifications without departing from the principle of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. A method for optimizing the installation location of a quantum source, characterized in that, The method comprises: setting a first position of a quantum source installed on a wing of a first aircraft, wherein the first position comprises an initial angle between the first aircraft and a first object and an initial position of the quantum source on the wing; comparing the first position with a plurality of predetermined positions to obtain a first predetermined position to which the first position belongs; the plurality of predetermined positions comprise: when the quantum source is installed on the wing of the first aircraft, taking any point on the two ends of the wing as an origin, determining the boundary of the wing as an X axis from the origin, and equally dividing the X axis according to a set distance to obtain a plurality of different distance intervals; when the first aircraft in which the quantum source is located travels from a starting position to an ending position, obtaining a total zenith angle of a receiving telescope of the first object, equally dividing the total zenith angle according to a predetermined angle to obtain a plurality of different angle intervals; for each angle interval, changing each distance interval to obtain the plurality of predetermined positions; based on the first predetermined position, obtaining a first quantum bit error rate and a first drift offset of an on-board quantum key distribution system corresponding to the first predetermined position; based on the first quantum bit error rate and the first drift offset and a plurality of preset quantum bit error rates and drift offsets of the on-board quantum key distribution system, determining a target quantum bit error rate and a target drift offset; based on the target quantum bit error rate and the target drift offset, obtaining a target position in the plurality of predetermined positions; adjusting the quantum source from the first position to the target position.

2. The method of claim 1, wherein, The comparing the first position with a plurality of predetermined positions to obtain a first predetermined position to which the first position belongs comprises: comparing the initial angle in the first position with each angle interval in the plurality of predetermined positions to obtain a target angle interval; comparing the initial position with each distance interval corresponding to the target angle interval to obtain the first predetermined position.

3. The method of claim 1, wherein, Before the determining a target quantum bit error rate and a target drift offset based on the first quantum bit error rate and the first drift offset and a plurality of preset quantum bit error rates and drift offsets of the on-board quantum key distribution system, the method further comprises: based on the plurality of predetermined positions, obtaining a plurality of preset quantum bit error rates and drift offsets of the on-board quantum key distribution system, wherein each predetermined position corresponds to a quantum bit error rate and a drift offset.

4. The method of claim 1, wherein, The determining a target quantum bit error rate and a target drift offset based on the first quantum bit error rate and the first drift offset and a plurality of preset quantum bit error rates and drift offsets of the on-board quantum key distribution system comprises: The first quantum bit error rate and the first drift offset are compared with a plurality of preset quantum bit error rates and drift offsets one by one, and when the first quantum bit error rate and the first drift offset are less than or equal to the plurality of preset quantum bit error rates and drift offsets, the first quantum bit error rate and the first drift offset are determined as the target quantum bit error rate and the target drift offset. When the first quantum bit error rate and the first drift offset are greater than the plurality of preset quantum bit error rates and drift offsets, the minimum quantum bit error rate and the minimum drift offset in the plurality of preset quantum bit error rates and drift offsets are determined as the target quantum bit error rate and the target drift offset.

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