Aircraft flight height calculation method, calculation processing device, readable storage medium and program product

Abstract

The invention relates to a method for calculating the flight height of an aircraft based on a numerical weather forecast model, and the method comprises the steps: determining the flight route and the flight duration of the aircraft, and reading the topographic data on the flight route; initializing a numerical weather forecast model; operating the numerical weather forecast model to obtain a meteorological data set corresponding to the flight time of the aircraft on the flight route; calculating the meteorological data set through interpolation to obtain a meteorological data set corresponding to the flight time of the aircraft on the flight route; and calculating the flight height of the aircraft on the flight route along with the flight time change according to the meteorological data set. The precision of aircraft pressure altitude calculation is remarkably improved, and the method has important significance in improving the flight safety of civil aircrafts.

Description

Technical Field

[0001] The invention belongs to the field of aircraft flight altitude calculation, and in particular relates to an aircraft flight altitude calculation method based on a numerical weather forecast model. Background Art

[0002] Aircraft altitude is an important parameter of the Terrain Awareness and Warning System (TAWS), and usually uses the pressure altitude and the altitude provided by the Global Navigation Satellite System (GNSS) as the altitude. Usually in the forward-looking terrain warning system, by comparing the elevation data on the route and the real-time aircraft flight altitude, a warning is given when there is a risk of terrain collision to avoid accidents. This requires the aircraft altitude to be accurate enough to ensure safety to the greatest extent. Usually, due to the influence of complex terrain, there is a possibility of signal transmission failure, and the GNSS altitude cannot be obtained. Therefore, the pressure altitude is often used as the aircraft altitude, which is displayed in real time on the integrated monitoring system.

[0003] In the prior art, an effective solution for low temperature weather conditions is to perform low temperature altitude correction. The barometric altimeter on the aircraft indicates the altitude calibrated under the international standard atmospheric pressure conditions, that is, the standard sea level pressure and standard temperature lapse rate. In other words, the barometric altitude correction table is an air pressure value based on the International Standard Atmosphere (ISA). The deviation of actual atmospheric conditions from ISA will cause errors in the measurement of the above-mentioned barometric altimeter. The deviation of atmospheric conditions is mainly reflected in the two aspects of air pressure and temperature. The error caused by non-standard atmospheric pressure can be corrected by adjusting the altimeter benchmark, however, the error caused by non-standard temperature cannot be corrected by this method. The influence of temperature on altitude will affect the spacing of isobaric surfaces, thereby affecting the indicated altitude value of the barometric altimeter.

[0004] Pressure altitude is calculated by the onboard equipment installed on the aircraft, which is calculated by a simplified pressure altitude formula. There are many assumptions in the traditional pressure altitude formula, including: the calculated altitude is below 11 kilometers; the sea level pressure is 1013.25hPa; the sea level temperature is 15°C; the temperature from the ground to the altitude to be calculated is linearly decreasing; and the air between the area to be calculated and the ground is static and dry. However, in actual situations, the real atmospheric environment is quite different from the assumed conditions. The atmospheric environment changes with the year, season, day and night, especially with the region and terrain. The above differences in conditions cause a large error between the aircraft flight altitude calculated by the pressure altitude formula and the actual altitude. This altitude calculation error will challenge the pilot's altitude judgment and control, and seriously affect flight safety.

[0005] Based on the above problems, the existing solution is to reduce the error between the altitude calculation result and the actual flight altitude by correcting the pressure altitude formula. At present, pilots use the "Flight Altitude Correction Table" to correct the altitude calculated by the pressure altitude formula, but this method is not conducive to the pilot's real-time viewing. There is also a method of correcting the pressure altitude formula to calculate the aircraft's flight altitude through the atmospheric statics equation. By estimating the error of the pressure altitude, calculating the compensation of GPS and radio altitude, and finally determining the aircraft's flight altitude. It also includes outputting longitude and latitude through GNSS, combining time information, and using the global monthly average sea level pressure data table to correct the sea level pressure and sea level temperature in the pressure altitude formula to calculate the corrected aircraft flight altitude.

[0006] Most of the above-mentioned aircraft flight altitude calculation methods use sea level pressure and sea level temperature based on standard atmospheric pressure, or finite variables in the modified pressure-height formula. However, none of the above methods take into account the impact of comprehensive factors such as real atmospheric pressure, temperature, density and vertical temperature lapse rate on the calculation of aircraft flight altitude. At the same time, the above methods cannot predict the atmospheric state within a certain period of time in the future, and cannot meet the requirements for calculating the accuracy of aircraft flight altitude in complex terrain, especially in complex terrain.

[0007] Therefore, the civil aviation market is in urgent need of a calculation method that can overcome the above problems and accurately calculate the flight altitude of the aircraft. At the same time, it can predict the atmospheric state in a certain period of time in the future to improve the flight safety of the aircraft and provide reliable flight guidance information for pilots. Summary of the invention

[0008] Problems to be solved by the invention

[0009] This application is formed to solve the above problems, and its purpose is to provide a flight altitude calculation method that can accurately calculate the flight altitude of an aircraft under complex atmospheric and terrain conditions, and at the same time, the method can predict the atmospheric state within a certain period of time in the future. This application further provides a computing processing device, a computer-readable medium, and a computer program product for implementing the above aircraft flight altitude calculation method.

[0010] Technical solutions adopted to solve technical problems

[0011] The present application provides a method for calculating the flight altitude of an aircraft, characterized in that the calculation method comprises:

[0012] Reading terrain data on the flight route according to the flight route and flight duration of the aircraft;

[0013] Initialize the numerical weather forecast model;

[0014] Running the numerical weather forecast model to obtain a meteorological data set corresponding to the flight time of the aircraft on the flight route;

[0015] According to the meteorological data set, a meteorological data group corresponding to the flight time of the aircraft on the flight route is obtained, wherein the meteorological data group at least includes sea level pressure, sea level temperature, vertical temperature lapse rate, disturbance potential, ground state potential, model altitude, model bottom layer temperature, model bottom layer altitude, temperature at the flight position, and air pressure;

[0016] The flight altitude of the aircraft on the flight route that changes with the flight time is calculated based on the meteorological data set.

[0017] It should be noted that in this article, "the meteorological data set corresponding to the aircraft flight time on the flight route" refers to, in the numerical weather forecast model, at a specific resolution, at a certain moment, a set of meteorological data of the grids near the position area of ​​the aircraft on the flight route at that moment.

[0018] It should be noted that in this article, "a set of weather data corresponding to the flight time of the aircraft on the flight route" refers to a set of weather data at the position of the aircraft on the flight route at a certain moment. n At this moment, the aircraft is at the corresponding coordinate point (X n ,Y n ,Z n ). Typically, the meteorological data group is calculated based on the corresponding meteorological data set, for example, by interpolation calculation.

[0019] In one embodiment of the present application, before initializing the numerical weather forecast model, a calculation area of ​​the numerical weather forecast model must also be set. The calculation area covers the flight route and includes a parent domain, a first subdomain nested in the parent domain, and a second subdomain nested in the first subdomain.

[0020] In one embodiment of the present application, initializing the numerical weather forecast model includes: setting an initial field and a boundary field of the numerical weather forecast model.

[0021] The initial field and boundary field of the weather forecast model are obtained by interpolating and pre-processing the model forecast data of the corresponding flight time covered by the flight route.

[0022] In one embodiment of the present application, the resolutions of the parent domain, the first subdomain and the second subdomain are respectively the parent domain resolution, the first subdomain resolution and the second subdomain resolution, wherein the parent domain resolution is greater than the first subdomain resolution, and the first subdomain resolution is greater than the second subdomain resolution.

[0023] In one embodiment of the present application, the running time of the numerical weather forecast model at least covers the flight time of the aircraft, and the data output time interval of the numerical weather forecast model is at least 1 minute.

[0024] The corrected aircraft flight altitude is calculated based on the meteorological data set and the pressure height formula. The corrected aircraft flight altitude calculation formula is:

[0025]

[0026] Among them, HGT correct is the corrected flight altitude, T nwp is the sea surface temperature, γ nwp is the vertical temperature lapse rate, P nwp is the air pressure at sea level, P is the air pressure at flight altitude, R is the gas constant, and g is the acceleration due to gravity.

[0027] The sea level pressure P nwp The calculation formula is:

[0028]

[0029] Among them, P low is the lowest atmospheric pressure in the model in the meteorological data set, Z low is the lowest model height in the meteorological data set, T SLP is the sea surface temperature in the meteorological data set, T surf is the surface temperature.

[0030] In one embodiment of the present application, the method for calculating the flight altitude of the aircraft is characterized in that, when calculating the flight altitude of the aircraft, the simulated flight altitude of the aircraft is calculated according to the disturbance potential and the ground potential in the meteorological data set, and the calculation formula is:

[0031] HGT=(PH+PHB) / g

[0032] Among them, HGT is the simulated flight altitude of the aircraft, PH represents the disturbance potential at the actual flight pressure of the aircraft, PHB represents the ground state potential at the actual flight pressure, and g is the gravitational acceleration.

[0033] In one embodiment of the present application, a computing device is also provided, which includes a memory, a processor, and a computing program stored in the memory, and the computer program is executed by the processor to implement the above-mentioned method for calculating the flight altitude of the aircraft.

[0034] In one embodiment of the present application, a computer-readable medium is further provided, wherein the computer-readable medium stores a computer program, and when the computer program is executed by a processor, the above-mentioned method for calculating the flight altitude of the aircraft is implemented.

[0035] In one embodiment of the present application, a computer program product is also provided, including a computer program, and when the computer program is executed by a processor, the above-mentioned method for calculating the flight altitude of the aircraft is implemented.

[0036] Effects of the Invention

[0037] According to the aircraft flight altitude calculation method of the present application, compared with the aircraft flight altitude calculation method in the prior art, high-resolution meteorological data on the aircraft flight route can be obtained through the numerical weather forecast model, and the meteorological variables of the aircraft flight route that change with the flight time can be further obtained, and the pressure height calculation formula can be further accurately corrected, and the elevation data can be further combined to obtain the precise height, especially under complex weather and complex terrain conditions, the aircraft flight altitude can be accurately calculated. The corrected height can effectively improve the safety of the aircraft flight. In addition, by using the numerical weather forecast model, the weather changes on the aircraft flight route within a certain period of time in the future can be obtained, which can further provide safety information for the aircraft flight and improve the flight safety of the aircraft. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] The drawings described herein are used to provide a further understanding of the present invention and constitute a part of the present invention. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation of the present invention. In the drawings:

[0039] Figure 1 is a flow chart showing a method for calculating the flight altitude of an aircraft according to an embodiment of the present application;

[0040] Figure 2 is an exemplary schematic diagram representing a numerical weather forecasting model used in the present application;

[0041] Figure 3 is a schematic diagram showing the structure of a computer device used in the aircraft flight altitude calculation method of the present application;

[0042] Figure 4 is an exemplary schematic diagram representing the sea level pressure in the meteorological data set of the present application;

[0043] Figure 5 is an exemplary schematic diagram representing the sea surface temperature in the meteorological data set of the present application;

[0044] Figure 6 It is a data comparison chart showing the flight altitude measured by the radio altimeter of the applicant in three flight tests on September 9, 2023, the flight altitude calculated by the standard pressure height formula, and the flight altitude calculated according to the calculation method of this application;

[0045] Figure 7 yes Figure 6 Deviations between the three flight altitudes measured and observed as described in;

[0046] Figure 8 yes Figure 6 Mean absolute error and root mean square error for the three flight heights measured as described in . DETAILED DESCRIPTION

[0047] Hereinafter, the main process of the aircraft flight altitude calculation method according to one embodiment of the present application will be described with reference to the accompanying drawings.

[0048] In order to enable those skilled in the art to better understand the embodiments of the present invention, the technical solutions in the embodiments of the present application will be clearly described below in conjunction with the accompanying drawings of the present invention. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without making creative work should belong to the protection scope of the present invention.

[0049] It should be noted that the terms "first", "second" etc. in the specification and claims of the present application are used to distinguish similar objects, and are not necessarily used to describe a specific order or sequential order. It should be understood that the terms used in this way can be interchangeable in appropriate circumstances, so that the embodiments of the present application described herein can be implemented in an order other than those illustrated or described herein. In addition, the terms "include", "have", "contain" and any of their variations are intended to cover non-exclusive inclusion. For example, the process, method, system, product or equipment comprising a series of steps or units need not be limited to those steps or units clearly listed, but may include other steps or units that are not clearly listed or inherent to these processes, methods, products or equipment.

[0050] Before describing the specific implementation manner of the present invention, the technical terms involved in the embodiments of the present invention are first described here.

[0051] The “flight altitude” mentioned in this application refers to the vertical distance of an aircraft relative to the surface of the earth, usually from sea level.

[0052] The "flight route" mentioned in this application refers to the flight path of an aircraft from its take-off point to its destination, and its flight path is usually pre-customized.

[0053] The "terrain data" or "elevation data" mentioned in this application refers to the digital information used in the Geographic Information System (GIS) to describe the earth's surface morphology, which includes attributes related to terrain, such as elevation, longitude and latitude, etc. Among them, the digital elevation model (DEM) is a special kind of terrain data, which realizes the digital simulation of the ground terrain through limited terrain elevation data. The terrain data used in this application is derived from the database of NASA ASTER GDEM digital elevation model.

[0054] The "numerical weather forecast model" described in this application refers to a forecasting technology that solves the state of the earth's atmospheric system grid by grid based on the laws of physics through numerical integration methods. This model simulates physical processes in the atmosphere, such as dynamics, thermodynamics, radiation and hydrological cycles, through computer calculations to predict future weather conditions. For example, the Global Medium-Term Weather Forecast System (IFS), the Global Forecast System (GFS), etc. The "numerical weather forecast model" in this application includes a full-scale forecast model, a mesoscale forecast model and a microscale forecast model. The appropriate numerical weather forecast model can be selected for calculation according to the span of the flight route.

[0055] The "initial field" described in this application refers to a three-dimensional snapshot of the atmospheric state at the starting point of the model calculation when performing numerical weather forecasting. The three-dimensional snapshot includes the values ​​of meteorological data such as temperature, humidity, air pressure, wind speed, etc. at a specific time node. In this application, the initial field is a three-dimensional snapshot of the atmospheric state when the aircraft takes off.

[0056] The "boundary field" described in this application refers to the boundary conditions that need to be obtained from a larger range of meteorological data in order to calculate the weather in a specific area in a numerical weather forecast model. Since numerical weather forecast models usually focus on the weather in a specific area, the calculation domain of the model will have a boundary. The boundary field is the meteorological conditions on this boundary, including temperature, humidity, air pressure, etc., which provide the model with meteorological information of the external environment of the calculation area. In this application, the boundary field at least includes the area covered by the flight route.

[0057] The "pressure-height formula" described in this application is a mathematical formula that relates air pressure to altitude, assuming that many factors are assumed to be ideal conditions, including sea level temperature, humidity, sea level pressure, vertical temperature lapse rate, etc.

[0058] In this application, "model altitude" refers to the altitude layers defined by the vertical coordinate system in the numerical weather forecast model. These altitude layers are the vertical intervals used by the model to simulate the state of the atmosphere. Numerical weather forecast models usually use a layered or columnar vertical coordinate system to divide the atmosphere into several layers, each layer representing a model altitude.

[0059] In this application, "model lowest layer height" generally refers to the height of the vertical layer closest to the ground in the numerical weather forecast model. This altitude layer is used to simulate the atmospheric state and is the layer closest to the ground. In addition, in this application, "model lowest layer pressure" and "model lowest layer temperature" refer to the pressure and temperature of the vertical layer closest to the ground in the numerical weather forecast model, respectively.

[0060] In addition, in this application, "base potential" is a type of meteorological data, which generally refers to the potential value under the climate average state at a specific vertical height. The average potential height value of a certain altitude layer or a certain area reflects the average horizontal potential state of the area on the climate scale. "Disturbance potential" in this application refers to the deviation between the actual potential and the base potential caused by the movement and change of the weather system. Through the calculation and analysis of the disturbance potential, the development of the weather system can be predicted and the movement trend can be calculated.

[0061] Figure 1 A flow chart of a method for calculating aircraft flight altitude according to an embodiment of the present application is shown.

[0062] First, in step ST1, the flight route and flight duration of the aircraft are determined, and the terrain data on the flight route is read. In this embodiment, the terrain data is derived from the Advanced Spaceborne Thermal Emission and Reflection Radiometer Global Digital Elevation Model (NASA ASTER GDEM V3). The elevation data set of NASA ASTER GDEM V3 with an accuracy of 30 meters is downloaded, and the digital image data file of the area covered by the flight route is read, which is a TIFF format file in this embodiment. The file is converted into a two-dimensional array for easy calculation.

[0063] It should be noted that in this embodiment, the terrain data used is NASA ASTER GDEM V3, but this is only an example and other types of terrain databases may also be implemented.

[0064] In step ST2, the numerical weather forecast model is initialized. The simulation area of ​​the numerical weather forecast model is set, and the simulation area includes a parent domain and multi-layer nested subdomains to ensure that the simulation area covers the flight route while identifying refined weather variables. In this embodiment, the simulation area includes a parent domain, a first subdomain nested in the parent domain, and a second subdomain nested in the first subdomain. The parent domain and the multi-layer nested subdomains need to satisfy that the resolution of the parent domain is greater than the resolution of the first subdomain, and the resolution of the first subdomain is greater than the resolution of the second subdomain. In this embodiment, the resolution of the relevant simulation area is configured to be 9km for the parent domain, 3km for the first subdomain, and 1km for the second subdomain to resolve high-resolution meteorological elements. The initialization operation of the numerical weather forecast model also includes setting the initial field and boundary field of the numerical weather forecast model. The initial field and the boundary field are the initial state and boundary state of the meteorological conditions in the numerical weather forecast model. In this embodiment, the meteorological state of the simulation area corresponding to the start of takeoff is the initial field, and the meteorological state of the minimum simulation area covering the simulated flight route, that is, the boundary of the parent domain, is the boundary field. In this embodiment, the meteorological data used is derived from the Global Weather Forecast System (GFS). Meteorological data corresponding to the flight time is downloaded from the GFS, and the meteorological data at least covers the simulation area in the numerical weather forecast model. The simulation area is gridded, and the meteorological data in the simulation area is calculated by horizontal interpolation calculation to obtain the meteorological data on the grid of the simulation area. An initial field of the meteorological state at the time of take-off of the aircraft is generated, and a boundary field of the meteorological state is generated in combination with the simulation area, which are used as the initial field and boundary field of the numerical weather forecast model respectively.

[0065] It should be noted that the resolution setting is not unique. Considering the computing power of the computer and the actual accuracy requirements, the resolution of the relevant simulation area is set as above in this embodiment. If a higher accuracy calculation result is required, the resolution can also be set more finely. In addition, the meteorological data in this embodiment uses the global weather forecast system, and can also come from other meteorological databases. It is only shown as an example in this embodiment and is not a specific limitation.

[0066] In step ST3, the numerical weather forecast model is run to obtain a meteorological data set corresponding to the flight time on the corresponding flight route. The running time of the numerical weather forecast model is set, and the running time at least covers the flight time of the aircraft. And the output time interval of the forecast data of the numerical weather forecast model is set. In this embodiment, the time interval is 1 minute to identify high-resolution meteorological variables at the flight time. The numerical weather forecast model is run to output a model calculation result file. The calculation result file includes a meteorological data set corresponding to the flight time on the flight route.

[0067] It should be noted that, in this embodiment, the output time interval of the forecast data of the numerical weather forecast model includes but is not limited to 1 minute. If a higher calculation accuracy is required, the time interval can also be set to be smaller.

[0068] In step ST4, the meteorological data set is interpolated to obtain a meteorological data set corresponding to the flight time of the aircraft on the flight route, and the meteorological data set includes sea level pressure, sea level temperature, vertical temperature lapse rate, disturbance potential and ground state potential. The meteorological data set is obtained by reading the calculation result file in step ST3 by a calculation tool. In this embodiment, the calculation tool is implemented as NCL software (The NCAR Command Language), which is a high-level language designed specifically for scientific data processing and data visualization, and is widely used in disciplines such as atmospheric science and ocean science. In this embodiment, the meteorological data set is interpolated by means of the NCL calculation tool. And according to the longitude and latitude of the aircraft flight and the pressure value, interpolation is performed in the horizontal direction and the vertical direction. Since the earth is a curved surface, the calculation grid adopts the Lamberto projection. The interpolation calculation method is implemented as four grid points around the specified longitude and latitude, using a weighted average interpolation inversely proportional to the distance. Finally, the meteorological data set at the longitude and latitude corresponding to the flight time of the aircraft is calculated, and the meteorological data set is a meteorological data set. The meteorological data set includes sea level pressure, sea level temperature, temperature vertical lapse rate, disturbance potential, ground state potential, model altitude, model lowest layer temperature, model lowest layer altitude, temperature at the flight position and air pressure.

[0069] It should be noted that in this embodiment, the computing tool uses NCL because it is widely used in atmospheric science and can be well adapted to the computing data type of the numerical weather forecast model. In this application, the computing tool can be implemented as other computing tools, including Python, Matlab, etc. The computing tools shown in this embodiment are only examples and are not intended to be limiting.

[0070] In step ST5, the flight altitude of the aircraft on the flight route that varies with the flight time is calculated based on the meteorological data set obtained in step ST4.

[0071] The first calculation method is to calculate the simulated pressure altitude of the aircraft through the base potential and disturbance potential corresponding to the position of the aircraft on the flight route over the flight time in the meteorological data set. The simulated pressure altitude is used as the flight altitude of the aircraft. Simulated pressure altitude HGT nwp The calculation formula is:

[0072] HGT nwp =(PH+PHB) / g

[0073] Among them, PH and PHB represent the disturbance potential and ground potential at the actual flight pressure of the aircraft.

[0074] In addition, the present application also provides a second method for calculating the flight altitude of an aircraft. In the second calculation method, the flight altitude of an aircraft is calculated by a pressure-height formula. However, it is necessary to correct the sea level pressure, sea level temperature, and vertical temperature lapse rate in the pressure-height formula to obtain a more accurate corrected flight altitude of the aircraft.

[0075] The calculation method for the sea level pressure on the flight path as a function of flight time is:

[0076]

[0077] Where SLP is the sea level pressure, P low and Z low represents the lowest pressure (hPa) and height (m) of the model, g and R are constants, representing the gravitational acceleration (9.81m / s 2 ) and the standard gas constant (287.05m 2 / (K·s 2 )).

[0078] Among them, T surf represents the surface temperature (K) and is calculated by the following formula:

[0079] T surf =T low -γZ low

[0080] Among them, T low represents the bottom layer temperature of the model, and γ represents the vertical temperature decrease rate, which is calculated by the following formula:

[0081] γ=(T air -T low ) / HGT

[0082] Among them, T air represents the temperature at which the aircraft actually flies, and HGT represents the model simulation altitude, which is obtained by the simulated pressure altitude calculation formula in the first calculation method, namely:

[0083] HGT=(PH+PHB) / g

[0084] Where PH and PHB represent the disturbance potential and ground potential at the actual flight pressure of the aircraft.

[0085] Finally, the above-mentioned sea level pressure, sea level temperature, and vertical temperature lapse rate are substituted into the pressure height formula to calculate the corrected pressure height HGT. correct The calculation formula is:

[0086]

[0087] Among them, P, SLP nwp , T nwp and γ represent the air pressure, sea level pressure, sea level temperature and vertical temperature lapse rate at the corresponding aircraft position on the flight route with the flight time, respectively.

[0088] The second flight altitude calculation method only corrects the limited calculation factors of sea level pressure, sea level temperature and vertical temperature gradient in the pressure height formula, and this calculation method has a low implementation cost. The first flight altitude calculation method takes into account more non-uniform change factors such as temperature and density in the vertical direction under different atmospheric conditions. The aircraft flight altitude calculated by the disturbance potential and the base state potential obtained by the numerical weather forecast model can guide the pilot to operate the aircraft with a more accurate aircraft flight altitude.

[0089] It should be noted that the above calculation formulas are all calculated in the NCL scientific computing tool. In addition, the numerical weather forecast model in this embodiment includes a full-scale weather forecast model, a mesoscale weather forecast model, and a microscale weather forecast model. The appropriate type of weather forecast model can be selected according to needs, such as the calculation accuracy requirements and the size of the area covered by the flight route.

[0090] Figure 2 2 is an exemplary schematic diagram of a numerical weather forecast model used in the present application, including a model top 21, a model height 25, a model bottom layer 22, a ground surface 23, a terrain 24, and an aircraft flight altitude 26. At the model top 21, the model bottom layer 22, and the ground surface 23, there are corresponding meteorological variables such as air pressure and temperature.

[0091] Figure 3 It is a schematic diagram of the structure of a computer device 500 used in the method for calculating the flight altitude of an aircraft of the present application. It should be noted that: Figure 3 The computer device shown is merely an example of an electronic device and should not bring any limitation to the functions and scope of use of the embodiments of the present application.

[0092] like Figure 3As shown, the computer device 500 includes a central processing unit (CPU) 501, which can perform various appropriate actions and processes according to a program stored in a read-only memory (ROM) 502 or a program loaded from the storage unit 108 to a random access memory (RAM) 503. In the RAM 503, various programs and data required for the operation of the computer device 500 are also stored. The CPU 501, the ROM 502, and the RAM 503 are connected to each other via a bus 504. An input / output (I / O) interface 505 is also connected to the bus 504.

[0093] The I / O interface 505 is connected to an I / O device, which may include an input unit 506 such as a keyboard and a mouse, an output unit 507 such as a liquid crystal display (LCD) and a speaker, a storage unit 508 such as a hard disk, and a communication unit 509 of a network interface card such as a modem. The communication unit 509 performs communication processing via a network such as the Internet. A drive 510 may also be connected to the I / O interface 505 as needed. In addition, a removable medium 511 may also be installed on the drive 510 as needed, so that a computer program read from the removable medium 511 can be installed in the storage unit 508 as needed.

[0094] In particular, the process described with reference to each figure, i.e., the calculation method of the aircraft flight altitude of the present application, can be implemented as a computer software program. For example, an embodiment of the present application includes a computer program product, which includes a computer program carried on a computer-readable medium, and the computer program contains program code for executing the method shown in each figure. In such an embodiment, the computer program can be downloaded and installed from the network through the communication unit 509, and / or installed from the removable medium 511. When the computer program is executed by the central processing unit (CPU) 501, the above-mentioned functions defined in the system of the present invention are executed.

[0095] It should be noted that the computer-readable medium shown in the present application may be a computer-readable signal medium or a computer-readable storage medium or any combination of the above two. The computer-readable storage medium may be, for example, but not limited to, an electrical, magnetic, optical, electromagnetic, infrared, or semiconductor system, device or device, or any combination of the above. More specific examples of computer-readable storage media may include, but are not limited to: an electrical connection with one or more wires, a portable computer disk, a hard disk, a random access memory (RAM), a read-only memory (ROM), an erasable programmable read-only memory (EPROM or flash memory), an optical fiber, a portable compact disk read-only memory (CD ROM), an optical storage device, a magnetic storage device, or any suitable combination of the above. In the present application, a computer-readable storage medium may be any tangible medium containing or storing a program that can be used by or in combination with an instruction execution system, device or device. In the present application, a computer-readable signal medium may include a data signal propagated in a baseband or as part of a carrier wave, which carries a computer-readable program code. This propagated data signal may take a variety of forms, including but not limited to electromagnetic signals, optical signals, or any suitable combination of the above. Computer-readable signal media may also be any computer-readable medium other than computer-readable storage media, which may send, propagate or transmit a program for use by or in conjunction with an instruction execution system, apparatus or device. The program code contained on the computer-readable medium may be transmitted using any appropriate medium, including but not limited to: wireless, wire, optical cable, RF, etc., or any suitable combination of the above.

[0096] As another aspect, the present application also provides a computer-readable storage medium, which may be included in the computer device described in this specification, or may exist independently without being assembled into the computer device. The above-mentioned computer-readable storage medium carries one or more programs, and when the above-mentioned one or more programs are executed by a computer device, the computer device implements the method as described in the above-mentioned embodiment and its variant. For example, the above-mentioned computer device can implement each step shown in each figure.

[0097] According to one aspect of the present invention, a computer program product is provided, the computer program product comprising computer instructions, the computer instructions being stored in a computer-readable storage medium. A processor of a computer device reads the computer instructions from the computer-readable storage medium, and the processor executes the computer instructions, so that the computer device executes the method provided in various optional implementations of the above-mentioned embodiments.

[0098] The applicant conducted actual experiments based on the aircraft flight altitude calculation method of the present application and the pressure height calculation method based on standard atmospheric pressure.

[0099] On September 9, 2023, the aircraft flew to a mountain peak at an altitude of 1,366 meters at a pressure altitude of 5,400 feet for a test mission, collecting three sets of flight altitude data. When the distance to the ground is close, the radio altimeter starts working, and the radio altitude plus the terrain altitude is selected as the true altitude.

[0100] The first set of altitude data is the aircraft flight altitude data collected by the radio altimeter.

[0101] The second set of altitude data is the aircraft flight altitude data obtained by the traditional pressure height formula calculation method.

[0102] The third set of altitude data is the aircraft flight altitude data calculated by the numerical weather forecast model of this application. Among them, the Chinese region is selected as the parent domain, the area near the mountain peak is selected as the nested area, and the simulation area is as follows: Figure 1 As shown, GFS forecast data and terrain data are downloaded to perform a 6-hour numerical weather forecast simulation.

[0103] The output file of the numerical weather forecast model with a resolution of 1 km in the second subdomain is read, the airborne latitude, longitude and pressure measurements are read, a variety of meteorological data variables are interpolated, and the two-dimensional distribution of sea level pressure, sea level temperature and vertical lapse rate along the flight direction with flight time is obtained.

[0104] A total of three flight missions were carried out, and the error of the flight altitude obtained by the calculation method of this application was less than the original pressure altitude. Figure 6 , Figure 7 As shown. According to statistics, the absolute error (MAE) of the flight altitude calculated using the standard pressure height formula is 163ft. Using the second calculation method in this application (correcting the sea level temperature, sea level pressure, and vertical temperature lapse rate in the pressure height formula), the absolute error is reduced to 132ft. Using the first calculation method in this application (calculated by ground state potential and perturbation potential), the absolute error is reduced to 20ft.

[0105] The root mean square error (RMSE) of the flight altitude calculated using the standard pressure height formula is 199ft. Using the second calculation method in this application, the root mean square error is reduced to 173ft. Using the first calculation method in this application, the root mean square error is reduced to 109ft. Both methods effectively reduce the error in calculating the flight altitude, such as Figure 8 shown.

[0106] It should be understood that the present application is not limited to the precise structures described above and shown in the drawings, and that various modifications, changes and combinations may be made without departing from the scope thereof. The scope of the present application is limited only by the appended claims.

Claims

1. A method for calculating the flight altitude of an aircraft, characterized in that: include: Reading terrain data on the flight route according to the flight route and flight duration of the aircraft; Initialize the numerical weather forecast model; Running the numerical weather forecast model to obtain a meteorological data set corresponding to the flight time of the aircraft on the flight route; According to the meteorological data set, a meteorological data group corresponding to the flight time of the aircraft on the flight route is obtained, wherein the meteorological data group at least includes sea level pressure, sea level temperature, vertical temperature lapse rate, disturbance potential, ground state potential, model altitude, model bottom layer temperature, model bottom layer altitude, temperature at the flight position, and air pressure; The flight altitude of the aircraft on the flight route that changes with the flight time is calculated based on the meteorological data set.

2. The method for calculating the flight altitude of an aircraft according to claim 1, characterized in that: Before initializing the numerical weather prediction model, a calculation area of ​​the numerical weather prediction model is set, where the calculation area covers the flight route and includes a parent domain, a first subdomain nested in the parent domain, and a second subdomain nested in the first subdomain.

3. The method for calculating the flight altitude of an aircraft according to claim 1, characterized in that: Initializing the numerical weather forecast model includes: setting an initial field and a boundary field of the numerical weather forecast model.

4. The method for calculating the flight altitude of an aircraft according to claim 2, characterized in that: The resolutions of the parent domain, the first subdomain and the second subdomain are respectively the parent domain resolution, the first subdomain resolution and the second subdomain resolution, wherein the parent domain resolution is greater than the first subdomain resolution, and the first subdomain resolution is greater than the second subdomain resolution.

5. The method for calculating the aircraft flight altitude according to claim 1, characterized in that: The running time of the numerical weather forecast model at least covers the flight time of the aircraft, and the data output time interval of the numerical weather forecast model is at least 1 minute.

6. The method for calculating the aircraft flight altitude according to claim 2, characterized in that: The initial field and boundary field of the weather forecast model are obtained by interpolating and pre-processing the model forecast data of the corresponding flight time covered by the flight route.

7. The method for calculating the aircraft flight altitude according to claim 1, characterized in that: The corrected aircraft flight altitude is calculated based on the meteorological data set and the pressure-height formula.

8. The method for calculating the aircraft flight altitude according to claim 7, characterized in that: The corrected calculation formula for the aircraft flight altitude is: Among them, HGT correct is the corrected aircraft flight altitude, T nwp is the sea surface temperature, γ nwp is the vertical temperature lapse rate, P nwp is the air pressure at sea level, P is the air pressure at flight altitude, R is the gas constant, and g is the acceleration due to gravity.

9. The method for calculating the aircraft flight altitude according to claim 8, characterized in that: The sea level pressure P nwp The calculation formula is: Among them, P low is the lowest atmospheric pressure in the meteorological dataset, Z low is the lowest altitude of the model in the meteorological dataset, T SLP is the sea surface temperature in the meteorological dataset, T surf is the surface temperature.

10. The method for calculating the aircraft flight altitude according to claim 1, characterized in that: When calculating the flight altitude of the aircraft, the simulated flight altitude of the aircraft is calculated according to the disturbance potential and the base potential in the meteorological data set, and the calculation formula is: HGT=(PH+PHB) / g Among them, HGT is the simulated flight altitude of the aircraft, PH represents the disturbance potential at the actual flight pressure of the aircraft, PHB represents the ground state potential at the actual flight pressure, and g is the gravitational acceleration.

11. A computing device, comprising a memory, a processor, and a computing program stored in the memory, characterized in that: When the computer program is executed by a processor, the method according to any one of claims 1 to 10 is implemented.

12. A computer-readable medium storing a computer program, characterized in that: When the computer program is executed by a processor, the method according to any one of claims 1 to 10 is implemented.

13. A computer program product, comprising a computer program, characterized in that When the computer program is executed by a processor, the method according to any one of claims 1 to 10 is implemented.

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