A method for simultaneous construction and reciprocal enhancement of physical map and radio frequency map

Abstract

The application discloses a method for simultaneously constructing and mutually enhancing a physical map and a radio frequency map, wherein a network-connected aircraft initializes the physical map and the radio frequency map according to historical data or a wireless channel model before performing a flight task, measures radio frequency data including wireless signal strength in a flight track during flight to determine whether a link between the aircraft and a ground base station is a line-of-sight link, and periodically senses an environment around a flight path during flight to obtain physical environment data representing building heights of the environment; the radio frequency data and the physical environment data are fused by mining an internal relationship between the building heights and electromagnetic propagation characteristics, and the simultaneous construction and enhancement of the physical map and the radio frequency map are realized. The application utilizes the internal relationship between the radio frequency map and the physical map, solves problems of large construction cost and complicated mapping of the physical map and the radio frequency map constructed separately, and builds a bridge for the construction of the two kinds of maps to realize environment-adaptive integrated sensing and communication.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of communication, and particularly relates to a method for simultaneously constructing and reciprocally enhancing a physical map and a radio frequency map. BACKGROUND

[0002] In recent years, unmanned aerial vehicles, especially unmanned aerial vehicles (UAVs), have been widely used in military and civilian fields such as reconnaissance, transportation, infrastructure inspection, agricultural irrigation, disaster rescue, etc. due to their high mobility, low cost and simple deployment. When performing different tasks, UAVs usually need to not only transmit sensor data, high-resolution images and other information to the ground terminal, but also need to perform high-precision environmental perception. The sixth generation (6G) mobile communication network in 2030 needs to meet the vision of seamless coverage of three-dimensional communication and perception, digital city and air-ground fusion network sensing integration, etc. However, to meet the above network sensing integration requirements, related devices in the region generally need to have high-precision sensing capabilities and powerful data processing capabilities, resulting in complex hardware structures of the devices, so that when using a large number of sensing integration devices, the cost factor has to be considered. In addition, different devices have the characteristics of homogeneity and overlap in sensing the same regional environmental features, resulting in a large amount of additional resource overhead. Therefore, if the communication and perception capabilities of the network can be maximized and the invalid repeated sensing overhead can be reduced, the application prospect of air-ground fusion network sensing integration will be broader.

[0003] In view of the above problems of repeated sensing of devices and large resource overhead, a new technology for recording the sensing and communication characteristics in the region, radio map technology, has been proposed in recent academia. It is considered that the environmental features and channel information sensed by devices at different positions in the region are collected and uploaded to a cloud, and processed, and finally the inherent environmental features and channel information in the space are recorded in the form of a map to alleviate the problem of difficult resource sharing in the air-ground fusion information network. Radio map technology aims to establish a cloud database that stores sensing resources. According to different storage indicators, it can be divided into three categories (1) communication performance indicator-based map (2) channel information-based map (3) channel environment feature-based map

[0004] In order to fully utilize the sensing integration resources, based on the existing academic radio frequency map idea, it is necessary to explore the communication and sensing mapping resource fusion method, and the existing mapping method is usually for single physical or radio frequency mapping, and does not consider integrating physical mapping and radio frequency mapping into one, mainly including the following forms:

[0005] (1) Offline establishment of physical map and radio frequency map. The physical map is established by high-precision field measurement, and the radio frequency map of the entire area is established by field measurement of channels or offline ray tracing according to the obtained physical map. This method has huge overhead, and needs to be repeated for different scenes and different times, which is not general and practical, and cannot fundamentally alleviate the problems of insufficient utilization of resources and large overhead.

[0006] (2) Flight control navigation and radio frequency building Figure One integrated. In the flight process of the network-connected aircraft, communication radio map data is collected, and the existing radio map existing in the cloud of the network side is updated. Before the network-connected aircraft flies, the cellular network side first constructs a three-dimensional space radio frequency map with low precision through historical flight communication data; the network-connected aircraft user acquires the three-dimensional space radio frequency map before performing the flight task, and plans the flight path and communication strategy according to the flight task and the three-dimensional space radio frequency map, so as to maintain the communication connection with the cellular network under the condition of completing the task; the network-connected aircraft executes the flight path and communication strategy, and measures the radio frequency map data in the flight process, and feeds back the radio frequency map data to the cellular network side; the cellular network side acquires the radio frequency map data, and learns by using the radio frequency map data to update the three-dimensional space radio frequency map. Further, the network-connected aircraft acquires the three-dimensional space radio frequency map updated by the cellular network side, to correct the flight path and communication strategy. This method considers radio frequency mapping and adaptive flight control, but does not integrate the perception results into the radio frequency mapping process, and does not fully utilize the integrated resources of sensing and control.

[0007] (3) Integration of physical mapping and positioning navigation (simultaneous localization and mapping, SLAM). SLAM is a classic research direction, and there are many mature researches and applications. Specifically, this method mainly uses the on-board sensor to obtain the position of the network-connected aircraft itself during the flight process of the network-connected aircraft, and also perceives the surrounding environment. Better positioning accuracy can obtain better mapping effect, and better mapping effect can in turn enhance the positioning accuracy of itself. This method only utilizes rough position information and surrounding environment perception information, ignores radio frequency communication data in the actual communication process, and does not consider the integration of perception physical mapping and communication radio map.

[0008] Based on the analysis of the three mapping methods using sensing resources at present, it can be seen that in the air-ground fusion network, a mapping method is needed to integrate the communication and sensing integrated resources, to avoid repeated acquisition of sensing information, improve overhead, and waste resources. SUMMARY

[0009] The application aims to provide a method for simultaneously constructing and mutually enhancing a physical map and a radio frequency map, which mines the internal coupling relationship between a three-dimensional physical map and electromagnetic propagation characteristics, and establishes a sensing-integrated resource fusion method to solve the technical problems of repeated acquisition of sensing information, increased overhead, and wasted resources.

[0010] To solve the above technical problems, the specific technical solutions of the application are as follows:

[0011] A method for simultaneously constructing and mutually enhancing a physical map and a radio frequency map, which takes radio frequency data on the flight path of a network-connected aircraft and its surrounding environment sensing information as input, and updates the radio frequency map and the physical map of the entire region online; the radio frequency map includes a link state map (LSM) representing whether the aircraft-to-base station link is a line-of-sight link or a non-line-of-sight link on the flight height plane and a channel gain map (CGM) representing the channel gain of the aircraft-to-base station link, and the physical map includes a building height map (BHM), comprising the following steps:

[0012] Step 1, initializing the radio frequency map and the physical map of the flight area of the aircraft, obtaining the position coordinates of the flight path of the aircraft when the aircraft communicates with the base station, and obtaining the radio frequency signal strength measurement data and the physical environment sensing measurement data corresponding to the position coordinates in the time sequence of the obtained flight path position coordinates;

[0013] Step 2, based on the radio frequency signal strength measurement data and the physical environment sensing measurement data in step 1, using the internal coupling relationship between electromagnetic wave propagation characteristics and the physical map, associating the flight position, sensing data, and radio frequency data of the aircraft, and then updating the radio frequency map and the physical map of the entire flight area of the aircraft in the time sequence of the obtained flight path position coordinates during the flight of the aircraft.

[0014] Further, the physical map is represented as a building height function, and the radio frequency map is represented as a function of channel gain and link state.

[0015] Further, step 1 is to obtain the aircraft's own position information, radio frequency measurement data set, and environment sensing measurement data set online during the flight of the aircraft using its onboard sensors including GPS, IMU, signal receiver, and radar.

[0016] Further, step 2 specifically includes:

[0017] Step 201, when the aircraft is at the current flight position, the current position radio frequency measurement data, i.e. received signal strength (RSS), is obtained by the on-board sensor, so as to update the channel gain map of the position where the aircraft has flown, and after a plurality of radio frequency measurement periods, environmental perception measurement data is obtained; it is assumed that environmental perception measurement is obtained after k radio frequency measurement periods, wherein k > > 1;

[0018] Step 202, based on the radio frequency communication received signal data of the current position and the historical flight position, the received signal strength is obtained, and based on the channel segmentation model, the existing signal detection technology is used to judge whether the communication link between the current aircraft and the base station is a line-of-sight link or a non-line-of-sight link;

[0019] Step 203, based on the environmental perception measurement data, the building height map of the flight area is updated online during the flight of the aircraft;

[0020] Step 204, the flight position, the perception measurement data and the radio frequency measurement data of the aircraft are associated according to the line-of-sight link or the non-line-of-sight link obtained in step 202; when the communication link between the aircraft and the base station is judged as a line-of-sight link, there is no three-dimensional space communication link blockage on the line between the aircraft and the base station, and the ground building height on the line is not higher than the line between the aircraft and the base station, so as to update the building height map, thereby reducing the environmental perception measurement error, and the communication link between any position on the line between the projection of the aircraft and the base station on the horizontal plane of the aircraft and the base station is a line-of-sight link, which is used to update the link state map; when the communication link between the aircraft and the base station is judged as a non-line-of-sight link, the communication link between any position on the extension line of the line between the projection of the aircraft and the base station on the horizontal plane of the aircraft towards the aircraft and the base station is a non-line-of-sight link;

[0021] Step 205, the building height map obtained after the update in step 204 is used to update the link state map on the flight plane of the aircraft again, including correcting the signal detection error of the line-of-sight or non-line-of-sight link in step 202;

[0022] Step 206, steps 201-205 are repeated for different flight positions during the flight until the flight task is completed;

[0023] Step 207, for the positions in the flight area where the link state map and the building height map are not updated, the initial values of the line-of-sight link LoS and 0 corresponding to the maps are directly used to complete, or the K-neighbor interpolation method is used to complete the link state map and the building height map; after the link state map is obtained, the channel gain map is obtained from the link state map according to the segmentation channel model, the distance between the aircraft and the base station, and the related channel parameters.

[0024] Further, the physical map and the radio frequency map of the flight area of the aircraft constitute a database for storing the optimal channel information and physical information based on the position information, and for each flight position of the aircraft, the physical map and the radio frequency map database of the flight area of the aircraft are simultaneously updated by fusing the radio frequency measurement data and the environment perception data.

[0025] Further, the method for simultaneously constructing and mutually enhancing the physical map and the radio frequency map is an online mapping method; based on the flight speed of the aircraft or the flight environment and other factors, when the flight speed of the aircraft is slow or the flight environment is simple, the measurement data accuracy of the aircraft is high, the cycle k value of the environment perception measurement is a value related to the measurement data accuracy, and is set to a value greater than 5 and less than 20; when the flight speed of the aircraft is fast or the flight environment is complex, the measurement data accuracy of the aircraft is low, the environment perception measurement frequency and the radio frequency measurement frequency can be improved, and the k value is reduced until the mapping accuracy is met.

[0026] The method for simultaneously constructing and mutually enhancing the physical map and the radio frequency map has the following advantages:

[0027] (1) The method can fully utilize the radio measurement and perception measurement data of the aircraft, which reflect the actual physical environment and signal propagation environment, and can be used for constructing the physical map and the radio frequency map, thereby ensuring no repeated perception and reducing the perception overhead.

[0028] (2) The method can utilize the existing network-connected aircraft in the network, and can construct the radio frequency map and the physical map online during the execution of the task of the aircraft, thereby being suitable for different air-ground communication scenarios and flight tasks, having strong flexibility, and having wide application range.

[0029] (3) The method can fully utilize the existing sensors in the network, such as the aircraft onboard sensors and the sensors for environment perception of the network side, and the data association in steps 204 and 205 can actually be the perception and communication data of the entire network side, so that repeated perception and resource overhead can be reduced. BRIEF DESCRIPTION OF DRAWINGS

[0030] Figure 1 is a principle schematic diagram of the radio frequency data enhancing the physical map and the radio frequency map provided by the embodiment of the application;

[0031] Figure 2 is a principle schematic diagram of the perception data enhancing the physical map and the radio frequency map provided by the embodiment of the application;

[0032] Figure 3 is an environment perception measurement model of the embodiment of the application, and is a principle schematic diagram of the relationship between the reflection point position and the building height.

[0033] Figure 4 is an example schematic diagram of online simultaneous construction of a physical map and a radio frequency map based on radio and perception data fusion of a networked aircraft provided by an embodiment of the application;

[0034] Figure 5 is an example flowchart of online simultaneous construction of a physical map and a radio frequency map based on radio and perception data fusion of a networked aircraft provided by an embodiment of the application. DETAILED DESCRIPTION

[0035] In order to better understand the purpose, structure and function of the application, the application of a method for simultaneously constructing a physical map and a radio frequency map and mutual enhancement will be further described in detail below in combination with the drawings.

[0036] In order to solve the problem of integrated sensing resource sharing, the application proposes a mapping method, that is, a method for simultaneously constructing and mutually enhancing a physical map and a radio frequency map based on radio measurement and perception measurement of a networked aircraft. By associating and fusing radio frequency data and environmental perception data during aircraft flight, a database of a physical map and a radio frequency map fusion is established to record environmental information and channel information in the flight area, avoid repeated perception, realize reuse of resources, and maximize the ability of unmanned aerial vehicles to fly, perceive and communicate in unknown and complex environments.

[0037] In this embodiment, referring to the flowchart shown in Figure 4 , a method for simultaneously constructing and mutually enhancing a physical map and a radio frequency map is provided, including the following steps:

[0038] Step 1, initialize the radio frequency map and the physical map of the flight area of the aircraft, and the aircraft plans a flight path according to the initial conditions of the flight task.

[0039] Step 2.1, when the aircraft communicates with the base station, the aircraft uses its onboard sensors such as GPS, IMU, signal receiver, radar, etc. to obtain position information online at the current flight position. The position of the aircraft at time t is marked as q(t). Through the onboard sensors, the radio frequency measurement data-received signal strength R(t) at the current position can be obtained, and the channel gain map at the position where the aircraft has flown can be updated. Every k radio frequency measurement period, environmental perception measurement data around the flight path is obtained.

[0040] Step 2.2, based on the radio frequency measurement data of the current position and the historical flight position, the received signal strength is obtained, and according to the channel segmentation model, the communication link between the current aircraft and the base station side is judged to be a line-of-sight link or a non-line-of-sight link through signal detection and machine learning online.

[0041] Step 2.3, based on the environmental perception measurement data, the building height map of the flight area can be updated online during the flight of the aircraft.

[0042] Step 2.4, according to the line-of-sight link or non-line-of-sight link obtained in step 2.2, the flight position of the aircraft, the perception data, and the radio frequency data are associated respectively. As shown in Figure 1 When the communication link between the aircraft and the base station is determined to be a line-of-sight link, there is no three-dimensional space communication link obstruction on the connection between the aircraft and the base station, and the ground building height on the connection is not higher than the connection between the aircraft and the base station, so as to update the building height map, reduce the environmental perception measurement error, and the projection point of the aircraft and the base station on the horizontal plane of the aircraft is a line-of-sight link at any position to the base station communication link, which can be used to update the link state map; when the communication link between the aircraft and the base station is determined to be a non-line-of-sight link, the communication link between the aircraft and the base station on the horizontal plane of the aircraft is a non-line-of-sight link at any position on the extension line towards the aircraft.

[0043] Step 2.5, for the building height map obtained after updating in step 2.4, as shown in Figure 2 According to the geometric relationship, the position of the link blocked by the building on the flight plane of the aircraft can be calculated, which is used to update the link state map on the flight plane of the aircraft again, including correcting the non-line-of-sight / line-of-sight link signal detection error in step 2.2.

[0044] Step 2.6, repeat steps 2.1-2.5 for different flight positions during the flight until the flight task is completed.

[0045] Step 2.7, for the positions in the flight area where the link state map and the building height map are not updated, directly use the initial values of the line-of-sight link LoS and 0 corresponding to the map to complete, or use the K- nearest neighbor interpolation method to complete the link state map and the building height map. After obtaining the link state map, according to the line-of-sight / non-line-of-sight segmented channel model, the distance between the aircraft and the base station, and the related channel parameters, the channel gain map is obtained from the link state map.

[0046] Wherein:

[0047] The network-connected aircraft in the network initializes the physical map and the radio frequency map according to historical data or a wireless channel model before performing a flight task, measures radio frequency data including wireless signal strength in a flight trajectory during the flight, thereby judging whether a link between the aircraft and a ground base station is a line-of-sight link, and periodically senses an environment around a flight path during the flight, thereby obtaining physical environment data representing building heights in the environment; the radio frequency data and the physical environment data are fused by mining an internal relationship between the building height information and electromagnetic propagation characteristics, thereby realizing simultaneous construction and mutual enhancement of the physical map and the radio frequency map. The internal relationship between the radio frequency map and the physical map is utilized, and problems such as large overhead and complicated construction process of a separate construction method of the physical map and the radio frequency map are solved, thereby building a bridge for construction of the physical map and the radio frequency map, to realize environment-adaptive sensing and communication integration.

[0048] In one embodiment, Figure 4 A network-connected aircraft flight and communication scenario in an urban environment is shown according to an exemplary embodiment, and it can be seen that signal propagation links between the aircraft and the ground base station are greatly affected by the surrounding environment, especially the buildings. By sensing, a height map of the buildings can be established, and an environment map can be roughly depicted. Before performing a task, the aircraft downloads a coarse-grained physical map and a radio frequency map, and at the same time, a flight path of the aircraft is planned.

[0049] Further, steps 2.1 to 2.5 can be repeated until the task is completed or timed out, to ensure the integrity of the executed flight task.

[0050] The method is not only suitable for a simple scenario of a single aircraft and a single base station, but also suitable for a complex scenario of multiple aircraft users and multiple base stations, different types of mapping cooperation strategies can be designed according to different scenarios, and the whole region mapping construction can be accelerated.

[0051] In one embodiment, Figure 1 and Figure 2 The correlation principle diagram of online simultaneous construction of the physical map and the radio frequency map mentioned in the application is shown according to an exemplary embodiment. Figure 3 The principle diagram of the relationship between the reflection point position and the building height is shown in this embodiment; Figure 4 The actual scene and effect example diagram of the online simultaneous construction method of the physical map and the radio frequency map based on radio and sensing data fusion of the network-connected aircraft is shown according to an exemplary embodiment. The physical map and the radio frequency map are simultaneously constructed by running the online simultaneous construction method of the physical map and the radio frequency map based on radio and sensing data fusion of the network-connected aircraft online according to the radio communication data and the environment sensing data collected by the aircraft users in different flight positions.

[0052] h represents the flight height of the aircraft, q(t) = (x(t), y(t)) represents the position of the aircraft mapped on the ground at time t, and {q(t), 0≤t≤T} represents the flight path of the aircraft. Use to represent the physical map (building height map), to represent the radio frequency map (link state (LoS / NLoS) map), to represent the height of the building at the (x, y) position, to represent the link state of the aircraft at the (x, y) position, and δt is the time slot length of two radio frequency communication data measurements. The nth communication time slot, r[q(nδt)] represents the received signal strength at q(nδt), which is simply denoted as r[q(n)] and q(n). After a number of radio frequency measurement periods, an environmental perception measurement data is obtained, to represent the perception result in the direction at m = kδt. is the environmental perception direction of the aircraft. Use Ψ(A, B) to represent the line connecting points A and B on the flight plane, to represent the extension of the AB line on the flight plane towards point B.

[0053] Based on the above definitions, an exemplary embodiment of the above-mentioned method for simultaneously constructing a physical map and a radio frequency map and a reciprocal enhancement method is proposed, and the specific implementation steps can be summarized as follows:

[0054] Step 1, map initialization phase. According to the historical data of the cellular network side, the coarse-grained physical map and the radio frequency map are initialized in the region.

[0055] Step 2.1, information acquisition phase. At the nth communication time, when the aircraft communicates with the base station, the aircraft uses its onboard sensors such as GPS, IMU, signal receiver, radar, etc. to obtain position information q(n) = (x(n), y(n)) at the current flight position online. Through the onboard sensor, the radio frequency measurement data r[q(n)] at the current position can be obtained, and the channel gain map at the current position can be updated. If n = uk, i.e. the current nth time (environmental perception is performed every k time slots), an environmental perception measurement data can be obtained - the distance of the building reflection point

[0056] Step 2.2, information processing phase. Based on the radio frequency measurement data r[q(i)] at the current position and the historical flight position, i = 1, 2…n, according to the segmented channel model, the signal detection and machine learning algorithm are used to judge online whether the current aircraft and the base station communication link is a line of sight link Or a non-line-of-sight link

[0057] Step 2.3, Information Processing Stage. Based on the environmental perception measurement data from Step 2.1—distance to building reflection points. like Figure 3 As shown, based on environmental perception data By relating the position and height of the reflection point to the geometric relationship, the perceived position and height of the reflection point on the building can be obtained. The specific calculation method is as follows:

[0058]

[0059]

[0060]

[0061] Therefore, the building height map of the flight area can be updated online during the flight of the aircraft. That is, in position Building height It should not be lower than Right now

[0062]

[0063] Step 2.4, Data Association Stage (Map Isomorphism Stage). Based on the line-of-sight (LAS) or non-LAS link obtained in Step 2.2, the aircraft's flight position, sensing data, and radio frequency data are associated respectively. For example... Figure 1 As shown, when the communication link between the aircraft and the base station is determined to be a line-of-sight link, there is no physical obstruction in three-dimensional space. For the position q′∈Ψ(A, q(n)) on the line connecting the projection points of the aircraft and the base station on the horizontal plane of the aircraft, the height of the buildings on the line is not higher than the line connecting the aircraft and the base station, reducing the error of environmental perception measurement. Moreover, for any q′, its communication link with the base station is a line-of-sight link, that is... When determined to be a non-line-of-sight (NLS) link, the communication link from the location on the extended line connecting the aircraft's flight plane and the base station's projection points on the aircraft's horizontal plane to the base station is a NLS link, meaning there is...

[0064] Step 2.5, Data Association Stage (Map Isomorphism Stage). For the building height map obtained after updating 2.4, such as... Figure 2 As shown, based on geometric relationships, the location where the link on the aircraft's flight plane is blocked by a building can be calculated, which is used to update the link status map in space again, including correcting the line-of-sight or non-line-of-sight signal detection errors in step 2.2.

[0065] Step 2.6, for different flight positions at different times during flight, repeat steps 2.1-2.5 until the end of the flight mission.

[0066] Step 2.7, for the position in the flight area where the link state map and the building height map are not updated, directly use the initial value of the corresponding map to complete the LoS and 0, or use the K-neighbor interpolation method to complete the link state map and the building height map. After obtaining the link state map, the channel gain map is obtained from the link state map according to the segmented channel model, the distance between the aircraft and the base station, and the related channel parameters.

[0067] The above method obtains radio frequency communication measurement data and environmental perception measurement data online through the on-board sensor during the flight of the aircraft, and associates the flight position of the aircraft, the perception data, and the radio frequency data according to the LoS and NLoS determined respectively. Based on the association between the physical map and the radio frequency map, the communication and perception resources obtained during the flight of the aircraft can be used jointly to construct the physical map and the radio frequency map in the flight area of the aircraft, and then applied to the non-perception devices in the entire area, reducing the sensing resource overhead of the network and reducing the repeated sensing of the network. For different flight paths of the same aircraft or different aircraft users, steps 2.1-2.5 can be repeated to improve the accuracy and timeliness of the map.

[0068] In summary, the present application fuses the aircraft user position information, integrates the sensing resources in the air-ground network by combining the on-board sensing capability of the aircraft, mines the inherent association between the physical map and the radio frequency map, explores a new method of simultaneous construction and mutual enhancement of the physical map and the radio frequency map, solves the problem of non-adaptation of sensing resources to different devices, improves the sustainable utilization capability of sensing resources in the network, and enables non-sensing devices in the network to obtain gains in sensing capability, thereby improving the overall performance of the air-ground network sensing.

[0069] It can be understood that the present application is described by some embodiments, and those skilled in the art know that various changes or equivalent replacements can be made to these features and embodiments without departing from the spirit and scope of the present application. In addition, under the guidance of the present application, these features and embodiments can be modified to adapt to specific conditions and materials without departing from the spirit and scope of the present application. Therefore, the present application is not limited by the specific embodiments disclosed herein, and all embodiments falling within the scope of the claims of the present application are within the scope of the present application.

Claims

1. A method for simultaneous construction and reciprocal enhancement of physical map and radio frequency map, characterized in that, Taking radio frequency data on the flight path of the networked aircraft and the surrounding environment perception information as inputs, the radio frequency map and the physical map of the entire region are updated online; the radio frequency map includes a link state map representing whether the aircraft-to-base station link is a line-of-sight link or a non-line-of-sight link on the flight height plane and a channel gain map representing the aircraft-to-base station link, and the physical map includes a building height map, comprising the following steps: Step 1, initialize the radio frequency map and the physical map of the aircraft flight region, when the aircraft communicates with the base station, obtain the position coordinates of the aircraft flight path, and obtain the radio frequency signal strength measurement data and the physical environment perception measurement data corresponding to the position coordinates in the time sequence of the obtained aircraft flight path position coordinates; Step 2, based on the radio frequency signal strength measurement data and the physical environment perception measurement data in step 1, the flight position, perception data, and radio frequency data are associated by utilizing the inherent coupling relationship between the electromagnetic wave propagation characteristics and the physical map, and then the radio frequency map and the physical map of the entire aircraft flight region are updated online in the time sequence of the obtained flight path position coordinates during the flight of the aircraft; Step 2 specifically includes: Step 201, the aircraft obtains the radio frequency signal strength measurement data at the current position through the on-board sensor, which can update the channel gain map at the position where the aircraft has flown, and obtains the environment perception measurement data after a number of radio frequency measurement periods; it is assumed that the environment perception measurement is obtained after k radio frequency measurement periods, where k >> 1; Step 202, based on the radio frequency communication received signal data at the current position and the historical flight position, the radio frequency signal strength data is obtained, and based on the channel segmentation model, the current aircraft and base station communication link is determined to be a line-of-sight link or a non-line-of-sight link according to the signal detection technology; Step 203, based on the environment perception measurement data, the building height map of the flight region is updated online during the flight of the aircraft; Step 204, the flight position, perception measurement data, and radio frequency measurement data are associated according to the line-of-sight link or non-line-of-sight link obtained in step 202; when the aircraft and base station communication link is determined to be a line-of-sight link, there is no three-dimensional space communication link blockage on the line connecting the aircraft and the base station, and the ground building height on the line connecting the aircraft and the base station is not higher than the line-of-sight link, so as to update the building height map, and the communication link from any position on the line connecting the projection of the aircraft and the base station on the horizontal plane to the base station is a line-of-sight link, which is used to update the link state map; when the aircraft and base station communication link is determined to be a non-line-of-sight link, the communication link from any position on the extension line of the line connecting the projection of the aircraft and the base station on the horizontal plane to the base station is a non-line-of-sight link; Step 205, the building height map obtained after updating in step 204 is used to update the link state map on the flight plane of the aircraft again, including correcting the line-of-sight or non-line-of-sight link signal detection error in step 202. Step 206, for different flight positions in the flight process, repeat steps 201-205 until the end of the flight task; Step 207, for the position in the flight area where the link state map and the building height map are not updated, directly use the initial value of the corresponding map to complete the line-of-sight link and 0, or use the K-neighbor interpolation method to complete the link state map and the building height map; after obtaining the link state map, according to the segmented channel model, the distance between the aircraft and the base station, and the related channel parameters, the channel gain map is obtained from the link state map.

2. The method of simultaneous construction and reciprocal enhancement of physical and radio frequency maps according to claim 1, wherein, The physical map is characterized as a building height function, and the radio frequency map is characterized as a function of channel gain and link state.

3. The method of simultaneous physical and radio frequency map construction and reciprocal enhancement of claim 1, wherein, Step 1 is to obtain the aircraft position information, radio frequency signal strength measurement data, and environment perception measurement data online during the flight of the aircraft using its onboard sensors including GPS, IMU, signal receiver, and radar.

4. The method of simultaneous physical map and radio frequency map construction and reciprocal enhancement of claim 1, wherein, The physical map and the radio frequency map of the flight area constructed during the flight of the aircraft constitute a database for storing the best channel information and physical information based on the position information, and for each flight position of the aircraft, the radio frequency measurement data and the environment perception data are fused to update the physical map and the radio frequency map database of the aircraft flight area at the same time.

5. The method of simultaneous physical map and radio frequency map construction and reciprocal enhancement of claim 1, wherein, The method is an online mapping method; based on the flight speed or flight environment of the aircraft, when the flight speed of the aircraft is slow or the flight environment is simple, the measurement data accuracy of the aircraft is high, the environment perception measurement period k value is set to a value related to the measurement data accuracy, which is greater than 5 and less than 20; when the flight speed of the aircraft is fast or the flight environment is complex, the measurement data accuracy of the aircraft is low, the environment perception measurement frequency and the radio frequency measurement frequency are improved, and the k value is reduced until the mapping accuracy is met.

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