Large altitude difference RTK tropospheric delay correction method and device based on meteorological satellite remote sensing

Abstract

The present invention discloses a method and device for correcting tropospheric delay of large altitude difference RTK based on meteorological satellite remote sensing. The method comprises: acquiring meteorological satellite remote sensing data in real time, and calculating a tropospheric zenith total delay grid product with the same time and space resolution according to the meteorological satellite remote sensing data; generating a tropospheric zenith total delay vertical lapse rate grid product with the same time resolution as the tropospheric zenith total delay according to the tropospheric zenith total delay grid product and combining it with a digital elevation model within the coverage of the meteorological satellite remote sensing data; and applying the tropospheric zenith total delay vertical lapse rate grid product to the tropospheric zenith total delay correction of large altitude difference RTK. The present invention realizes the tropospheric delay correction of large altitude difference RTK by obtaining the tropospheric zenith total delay vertical lapse rate based on real-time meteorological satellite remote sensing data.

Description

Technical Field

[0001] The present invention belongs to the field of GNSS (Global Navigation Satellite System) real-time precision positioning, and in particular relates to a large altitude difference RTK tropospheric delay correction method and device based on meteorological satellite remote sensing. Background Art

[0002] Real-Time Kinematic (RTK) with large elevation difference requires correction of tropospheric delay errors. There are three existing methods for correcting tropospheric delay for RTK with large elevation difference: (1) Based on the empirical tropospheric delay model, no ground meteorological station or GNSS base station is required. For example, the GPT series model or the standard meteorological parameters combined with the Saas model are used; (2) Ground meteorological stations are deployed on the ground to construct a vertical decrease model of tropospheric delay (such as the Saas model using measured meteorological parameters), or to refine the empirical global tropospheric delay (such as the GPT2w parameter integration model); (3) GNSS stations are deployed on the ground, and based on the ground GNSS stations, the tropospheric delay is solved and a vertical decrease model of tropospheric delay is constructed; or network RTK services are provided based on ground GNSS. Among the above three types of models, type (1) has low accuracy. Although types (2) and (3) have high accuracy, they require the deployment of meteorological stations or GNSS stations on the ground, which not only increases the construction cost, but also increases the complexity of data processing. Summary of the invention

[0003] In order to overcome the deficiencies of the above-mentioned prior art, the present invention provides a method and device for correcting tropospheric delay of large altitude difference RTK based on meteorological satellite remote sensing, which realizes the tropospheric delay correction of large altitude difference RTK by obtaining the vertical decrease rate of the total delay at the zenith of the troposphere based on real-time meteorological satellite remote sensing data.

[0004] According to one aspect of the present invention, there is provided a method for correcting tropospheric delay of a large altitude difference RTK based on meteorological satellite remote sensing, comprising:

[0005] Acquire meteorological satellite remote sensing data in real time, and calculate the tropospheric zenith total delay grid product with the same temporal and spatial resolution based on the meteorological satellite remote sensing data;

[0006] Based on the tropospheric zenith total delay grid product, combined with the digital elevation model within the coverage of meteorological satellite remote sensing data, a tropospheric zenith total delay vertical lapse rate grid product with the same time resolution as the tropospheric zenith total delay is generated;

[0007] The vertical lapse rate grid product of the total tropospheric zenith delay is applied to the tropospheric delay correction of large altitude difference RTK.

[0008] As a further technical solution, a vertical lapse rate grid product of the tropospheric zenith total delay with the same time resolution as the tropospheric zenith total delay is generated, including:

[0009] According to the coverage of the total tropospheric zenith delay, determine the coverage and grid size of the vertical lapse rate of the total tropospheric zenith delay;

[0010] Determining grid point locations according to the coverage of the tropospheric zenith total delayed vertical lapse rate and the grid size;

[0011] The vertical lapse rate of the tropospheric zenith total delay at each grid point is calculated one by one, and the tropospheric zenith total delay vertical lapse rate grid product is generated based on the vertical lapse rate of the tropospheric zenith total delay at all grid point positions.

[0012] As a further technical solution, the vertical decrease rate of the total tropospheric zenith delay at each grid point is calculated one by one, including:

[0013] According to the global empirical tropospheric delay model, the tropospheric zenith total delay and the corresponding elevation value at the grid points within a preset distance range around the grid point position are obtained to form at least three triplets consisting of the elevation value, the tropospheric zenith total delay at the elevation value, and the empirical tropospheric delay at the elevation value;

[0014] According to at least three of the triplets, a vertical decrease model of the total delay at the zenith of the troposphere is fitted to calculate the vertical decrease rate of the total delay at the zenith of the troposphere at the current grid point position.

[0015] As a further technical solution, the tropospheric zenith total delay vertical lapse rate grid product is applied to the large altitude difference RTK tropospheric delay correction, including:

[0016] Get the approximate position of the RTK operation, and obtain the vertical decrease rate of the total delay at the zenith of the troposphere corresponding to the approximate position;

[0017] The vertical decrease rate of the total delay at the zenith of the troposphere corresponding to the approximate position is substituted into the large height difference RTK positioning equation to obtain the coordinates of the mobile station.

[0018] As a further technical solution, a tropospheric zenith total delay grid product with the same temporal and spatial resolution is calculated based on the meteorological satellite remote sensing data, including:

[0019] Obtaining atmospheric precipitable water according to the meteorological satellite remote sensing data;

[0020] According to the atmospheric precipitable water, a tropospheric zenith wet delay is obtained;

[0021] According to the tropospheric zenith wet delay and in combination with the tropospheric zenith static delay, the tropospheric zenith total delay based on meteorological satellite remote sensing data is obtained.

[0022] According to one aspect of the present invention, there is provided a large height difference RTK tropospheric delay correction device based on meteorological satellite remote sensing, comprising:

[0023] The first main module is used to obtain meteorological satellite remote sensing data in real time, and calculate the tropospheric zenith total delay grid product with the same time and space resolution based on the meteorological satellite remote sensing data;

[0024] The second main module is used to generate a tropospheric zenith total delay vertical lapse rate grid product with the same time resolution as the tropospheric zenith total delay based on the tropospheric zenith total delay grid product and in combination with a digital elevation model within the coverage of meteorological satellite remote sensing data;

[0025] The third main module is used to apply the tropospheric zenith total delay vertical lapse rate grid product to the large altitude difference RTK tropospheric delay correction.

[0026] As a further technical solution, the second main module is further used to execute the following instructions:

[0027] According to the coverage of the total tropospheric zenith delay, determine the coverage and grid size of the vertical lapse rate of the total tropospheric zenith delay;

[0028] Determining grid point locations according to the coverage of the tropospheric zenith total delayed vertical lapse rate and the grid size;

[0029] The vertical lapse rate of the tropospheric zenith total delay at each grid point is calculated one by one, and the tropospheric zenith total delay vertical lapse rate grid product is generated based on the vertical lapse rate of the tropospheric zenith total delay at all grid point positions.

[0030] As a further technical solution, the third main module is further used to execute the following instructions:

[0031] Get the approximate position of the RTK operation, and obtain the vertical decrease rate of the total delay at the zenith of the troposphere corresponding to the approximate position;

[0032] The vertical decrease rate of the total delay at the zenith of the troposphere corresponding to the approximate position is substituted into the large height difference RTK positioning equation to obtain the coordinates of the mobile station.

[0033] According to one aspect of the present invention, there is provided an RTK positioning device, comprising: at least one processor, at least one memory and a communication interface; wherein the processor, memory and communication interface communicate with each other; the memory stores program instructions executed by the processor, and the processor calls the program instructions to execute the described method.

[0034] According to one aspect of the present specification, a non-transitory computer-readable storage medium is provided, wherein the non-transitory computer-readable storage medium stores computer instructions, wherein the computer instructions enable the computer to execute the method described above.

[0035] Compared with the prior art, the present invention has the following beneficial effects:

[0036] (1) The present invention calculates a tropospheric zenith total delay grid product with the same temporal and spatial resolution based on real-time meteorological satellite remote sensing data. Based on the tropospheric zenith total delay grid product and in combination with a digital elevation model within the coverage area of ​​the meteorological satellite remote sensing data, a tropospheric zenith total delay vertical lapse rate grid product with the same temporal resolution as the tropospheric zenith total delay is generated. The tropospheric zenith total delay vertical lapse rate grid product is applied to large-elevation-difference RTK tropospheric delay correction, thereby achieving large-scale, high-precision RTK tropospheric delay correction that is independent of ground measurement sites.

[0037] (2) The present invention performs large-difference RTK tropospheric delay correction based on meteorological satellite remote sensing data, and has good temporal resolution and timeliness. At the same time, due to the large coverage of meteorological satellites, a large-scale tropospheric zenith total delay vertical lapse rate product can be obtained for large-difference RTK tropospheric delay correction.

[0038] (3) The present invention performs large altitude difference RTK tropospheric delay correction based on meteorological satellite remote sensing data, without the need to deploy measurement sites, with low cost and low data processing complexity. BRIEF DESCRIPTION OF THE DRAWINGS

[0039] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, a brief introduction is given below to the drawings used in the embodiments or the description of the prior art. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0040] Figure 1 A schematic flow chart of a method for correcting large altitude difference RTK tropospheric delay based on meteorological satellite remote sensing provided in an embodiment of the present invention.

[0041] Figure 2A schematic diagram of a process for generating a tropospheric zenith total delay vertical lapse rate grid product provided in an embodiment of the present invention.

[0042] Figure 3 A schematic structural diagram of a large altitude difference RTK tropospheric delay correction device based on meteorological satellite remote sensing provided in an embodiment of the present invention.

[0043] Figure 4 A schematic diagram of the structure of an RTK positioning device provided in an embodiment of the present invention. DETAILED DESCRIPTION

[0044] In view of the current situation that there is a lack of large-scale, high-precision, and large-altitude-difference RTK tropospheric delay correction that is independent of ground measured sites, the present invention proposes a large-altitude-difference RTK tropospheric delay correction method based on meteorological satellite remote sensing, which realizes large-scale, high-precision, and large-altitude-difference RTK tropospheric delay correction that is independent of ground measured sites.

[0045] The basic probability and known technologies involved in the embodiments of the present invention are described below:

[0046] Tropospheric delay: The amount of delay an electromagnetic wave experiences as it passes through the troposphere.

[0047] Zenith Total Tropospheric Delay (ZTD): The delay of electromagnetic waves when they pass through the troposphere from the zenith direction, including static delay and wet delay.

[0048] Zenith Wet Tropospheric Delay (ZWD): The amount of delay in the ZTD due to the "wet" part of the atmosphere.

[0049] Zenith Tropospheric Static Delay (ZHD): The amount of delay in the ZTD due to the "dry" part of the atmosphere.

[0050] The relationship among ZTD, ZWD and ZHD is: ZTD=ZHD+ZWD. Among them, ZHD accounts for about 90% of ZTD and can usually be accurately expressed using the model. Affected by water vapor changes, ZWD changes greatly and the model expression accuracy is low.

[0051] The ZTD vertical reduction model can be expressed as:

[0052]

[0053] Among them, D m represents ZTD based on meteorological satellite remote sensing; D e represents the empirical tropospheric delay; represents the a priori ZTD correction value, that is, the difference between the two; H is the site elevation; a and b are model coefficients.

[0054] Double difference slant path tropospheric delay It can be calculated from the zenith tropospheric delay (ZTD) and the projection function:

[0055]

[0056] in, is the a priori double-difference tropospheric slant delay, and The projection function corresponding to satellites k and l; and are the a priori ZTD correction values ​​of station i and station j, respectively.

[0057] Meteorological remote sensing satellite: A remote sensing satellite used for meteorology, usually located in geostationary orbit, with the characteristics of large imaging range and high temporal resolution, such as China's Fengyun-4B and Japan's Hibiscus-8.

[0058] The terms "including" and "having" and any variations thereof in the specification and claims of the present invention and the above-mentioned drawings are intended to cover non-exclusive inclusions, for example, a process, method, system, product or apparatus comprising a series of steps or units is not necessarily limited to the steps or units explicitly listed, but may include other steps or units not explicitly listed or inherent to these processes, methods, products or apparatuses.

[0059] The block diagrams shown in the accompanying drawings are merely functional entities and do not necessarily correspond to physically independent entities. That is, these functional entities may be implemented in software, or in one or more hardware modules or integrated circuits, or in different networks and / or processor devices and / or microcontroller devices. The flowcharts shown in the accompanying drawings are merely exemplary and do not necessarily include all the contents and operations / steps, nor do they necessarily have to be executed in the order described. For example, some operations / steps may be further decomposed, while some operations / steps may be combined or partially combined, so the actual execution order may change according to the actual situation.

[0060] In order to make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments in the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention. In addition, the technical features in the various embodiments or single embodiments provided by the present invention are arbitrarily combined with each other to form a new technical solution. This combination is not restricted by the sequence of steps and / or the structural composition mode, but must be based on the ability of ordinary technicians in this field to achieve. When the combination of technical solutions is contradictory or cannot be achieved, it should be considered that this combination of technical solutions does not exist and is not within the scope of protection required by the present invention.

[0061] An embodiment of the present invention provides a large altitude difference RTK tropospheric delay correction method based on meteorological satellite remote sensing. Taking the Japanese meteorological remote sensing satellite Himawari-8 as an example, the large altitude difference RTK tropospheric delay correction process based on meteorological satellite remote sensing is introduced.

[0062] like Figure 1 As shown, the method includes:

[0063] Step 1: Acquire meteorological satellite remote sensing data in real time, and calculate the tropospheric zenith total delay grid product with the same time and space resolution based on the meteorological satellite remote sensing data.

[0064] Here, Himawari-8 real-time multi-band data is downloaded to perform large height difference RTK tropospheric delay correction. In the embodiment of the present invention, remote sensing data of meteorological satellites are obtained in real time, usually with a time resolution of 10 minutes and a spatial resolution of 1km-4km.

[0065] Optionally, after acquiring the meteorological satellite remote sensing data, it also includes: calculating the GNSS tropospheric zenith total delay based on the meteorological satellite remote sensing data to obtain a ZTD grid product with a coverage range of approximately 1 / 3 of the earth, a time resolution of 10 minutes, and a spatial resolution of 2 km.

[0066] Specifically, the GNSS tropospheric zenith total delay is calculated based on meteorological satellite remote sensing data, including:

[0067] Step 1.1, processing the meteorological satellite remote sensing data to obtain a large range of atmospheric precipitable water (PWV).

[0068] This step is based on the method of Du et al (2024), Atmospheric Research (DOI:j.atmosres.2024.107281) to calculate the real-time PWV product. Specifically, this step uses a stacked machine learning model, and its process includes: (1) using Himawari-8 multi-band data and ECMWF ERA5 data set water vapor products to build a random deep forest model and a back propagation neural network model; (2) inputting Himawari-8 real-time multi-band data to obtain the PWV estimation values ​​of the random deep forest model and the back propagation neural network model; (3) fusing the PWV values ​​of each model through a multivariate linear regression model.

[0069] Step 1.2, according to the atmospheric precipitable water volume (PWV), obtain the tropospheric zenith wet delay (ZWD). Preferably, in the embodiment of the present invention, when calculating the tropospheric zenith wet delay, an available method is a technical method based on the global Tm model.

[0070] Specifically, the embodiment of the present invention calculates the atmospheric weighted average temperature within the PWV product range based on the GTm3 model (DOI: 10.1093 / gji / ggu008) to obtain the conversion coefficient between PWV and ZWD:

[0071] ,

[0072] Convert real-time PWV products to real-time ZWD products:

[0073] .

[0074] It should be noted that the atmospheric weighted average temperature can be obtained from the GTm series model as well as the GPT series model. The specific method of obtaining the temperature can be implemented by using existing mature technologies, and the embodiments of the present invention will not be described in detail here.

[0075] Step 1.3, according to the tropospheric zenith wet delay, combined with the tropospheric zenith static delay, the tropospheric zenith total delay based on meteorological satellite remote sensing data is obtained.

[0076] Specifically, the global empirical tropospheric delay model GPT3 is used to calculate the ZHD within the ZWD range, and then the tropospheric zenith total delay (ZTD) product based on meteorological satellite remote sensing data is obtained, that is, the real-time ZTD product: ZTD = ZHD + ZWD.

[0077] Step 2: Based on the tropospheric zenith total delay grid product (hereinafter referred to as ZTD grid product) and in combination with the digital elevation model within the coverage of meteorological satellite remote sensing data, a tropospheric zenith total delay vertical lapse rate grid product (hereinafter referred to as ZTD vertical lapse rate grid product) with the same time resolution as the tropospheric zenith total delay is generated.

[0078] The embodiment of the present invention uses the SRTM product (Shuttle Radar Topography Mission) to obtain a digital elevation model within the coverage area of ​​meteorological satellite remote sensing data.

[0079] In the present invention, based on the aforementioned ZTD grid product and digital elevation model, a ZTD vertical lapse rate grid product with the same time resolution as the ZTD grid product is generated. Figure 2 As shown, the specific steps are:

[0080] Step 2.1, determine the coverage of the ZTD vertical lapse rate grid product based on the coverage of the ZTD grid product; determine the grid size based on the required spatial resolution and data availability, such as 1, 2, 3 times the grid size of the ZTD grid product.

[0081] For example, make sure that the coverage of the ZTD vertical lapse rate grid product is consistent with that of the ZTD grid product; set the grid size to 1km×1km.

[0082] Step 2.2, determine the grid point locations based on the coverage and grid size.

[0083] Step 2.3, based on the global empirical tropospheric delay model, such as the GPT series model and the UNB series model, obtain the empirical ZTD at the grid point. Obtain the ZTD and the corresponding elevation value at the grid point within a certain distance range around the grid point position to form a triple of ZTD (Dm), empirical ZTD (De), and elevation value (H). It should be noted that this step obtains no less than 3 triplets.

[0084] Step 2.4, fit the ZTD vertical decline model and calculate the vertical decline rate a of the grid points. Substitute the triple into the established ZTD vertical decline model: . Where D m is the ZTD at elevation H, D e is the empirical tropospheric delay at height H, is the difference between the two. a and b are the model coefficients to be estimated. The model requires at least 3 triplets to solve the coefficients a and b to be estimated. a is the ZTD vertical decline rate.

[0085] Repeat steps 2.3-2.4 to calculate the ZTD vertical lapse rate at other grid points and generate the ZTD vertical lapse rate grid product.

[0086] Step 3, applying the tropospheric zenith total delay vertical lapse rate grid product to the large altitude difference RTK tropospheric delay correction.

[0087] Step 3.1, the rover obtains the approximate position of the RTK operation. The ZTD vertical lapse rate a of the rover position is retrieved using the nearest neighbor method, that is, the ZTD vertical lapse rate a of the nearest grid point is obtained. Considering the short distance between the base station and the rover, it is assumed that the ZTD vertical lapse rates of the two are the same.

[0088] Step 3.2: Calculate the height difference Δh between the base station and the mobile station. With mobile station difference

[0089]

[0090] Based on the experience of the base station and the mobile station ZTD ( and ), calculate the a priori double-difference tropospheric slant delay

[0091]

[0092] in, and The projection functions corresponding to satellites k and l.

[0093] Step 3.3, by The double-difference slant path tropospheric delay is calculated by using the difference and projection function.

[0094]

[0095] Will Applied to the large height difference RTK positioning algorithm to solve the coordinates of the mobile station.

[0096] Compared with the existing methods, the embodiment of the present invention provides a large altitude difference RTK tropospheric delay correction method for meteorological satellite remote sensing, which has the advantages of high precision, large range, good real-time performance and low cost, as shown in Table 1.

[0097] Table 1 Comparison table of the method described in the embodiment of the present invention and the existing method

[0098]

[0099] The key to the correction of tropospheric delay in large-difference RTK is to obtain the vertical lapse rate of tropospheric delay at the RTK operation position. The large-scale, high-precision, high-real-time large-difference RTK tropospheric delay correction method proposed by the present invention is based on real-time meteorological satellite remote sensing data. Since meteorological satellite remote sensing data has high temporal resolution and can be obtained in real time, such as the Himawari imager (AHI) carried by Himawari-8, which has a temporal resolution of 10 minutes and a time delay of only a few minutes, it has good temporal resolution and timeliness. At the same time, the coverage of meteorological satellites is large, and a large-scale tropospheric delay (ZTD) vertical lapse rate product can be obtained for large-difference RTK tropospheric delay correction.

[0100] The implementation basis of each embodiment of the present invention is to implement programmed processing through a device with a processor function. Therefore, in engineering practice, the technical solutions and functions of each embodiment of the present invention are encapsulated into various modules. Based on this reality, on the basis of the above embodiments, an embodiment of the present invention provides a large altitude difference RTK tropospheric delay correction device based on meteorological satellite remote sensing, which is used to execute the large altitude difference RTK tropospheric delay correction method based on meteorological satellite remote sensing in the above method embodiment.

[0101] See also Figure 3 The device includes: a first main module, which is used to acquire meteorological satellite remote sensing data in real time, and calculate the tropospheric zenith total delay grid product with the same time and space resolution according to the meteorological satellite remote sensing data; a second main module, which is used to generate the tropospheric zenith total delay vertical lapse rate grid product with the same time resolution as the tropospheric zenith total delay according to the tropospheric zenith total delay grid product and the digital elevation model within the coverage of the meteorological satellite remote sensing data; and a third main module, which is used to apply the tropospheric zenith total delay vertical lapse rate grid product to the large elevation difference RTK tropospheric delay correction.

[0102] The large-difference RTK tropospheric delay correction device based on meteorological satellite remote sensing provided by the embodiment of the present invention is aimed at the current situation that there is a lack of large-scale, high-precision, and large-difference RTK tropospheric delay correction that does not rely on ground measurement sites. Figure 3 Several modules in it, based on meteorological satellite remote sensing, have achieved large-scale, high-precision RTK tropospheric delay correction with large altitude difference and independent of ground measurement sites.

[0103] It should be noted that the device embodiments provided by the present invention are used to implement the methods in the above method embodiments as well as the methods in other method embodiments provided by the present invention. The only difference is that the corresponding functional modules are set, and the principle is basically the same as the principle of the above device embodiments provided by the present invention. As long as the technical personnel in the field refer to the specific technical solutions in other method embodiments on the basis of the above device embodiments, obtain the corresponding technical means and the technical solutions composed of these technical means by combining the technical features, and on the premise of ensuring the practicality of the technical solutions, improve the modules in the above device embodiments to obtain the corresponding device class embodiments, which are used to implement the methods in other method class embodiments. For example:

[0104] Based on the content of the above device embodiment, as a preferred embodiment, the large height difference RTK tropospheric delay correction device based on meteorological satellite remote sensing provided in the embodiment of the present invention, the second main module is also used to execute the following instructions:

[0105] According to the coverage of the total tropospheric zenith delay, determine the coverage and grid size of the vertical lapse rate of the total tropospheric zenith delay;

[0106] Determining grid point locations according to the coverage of the tropospheric zenith total delayed vertical lapse rate and the grid size;

[0107] The vertical lapse rate of the tropospheric zenith total delay at each grid point is calculated one by one, and the tropospheric zenith total delay vertical lapse rate grid product is generated based on the vertical lapse rate of the tropospheric zenith total delay at all grid point positions.

[0108] Based on the content of the above device embodiment, as a preferred embodiment, the large height difference RTK tropospheric delay correction device based on meteorological satellite remote sensing provided in the embodiment of the present invention, the third main module is also used to execute the following instructions:

[0109] Get the approximate position of the RTK operation, and obtain the vertical decrease rate of the total delay at the zenith of the troposphere corresponding to the approximate position;

[0110] The vertical decrease rate of the total delay at the zenith of the troposphere corresponding to the approximate position is substituted into the large height difference RTK positioning equation to obtain the coordinates of the mobile station.

[0111] The embodiment of the present invention also provides an RTK positioning device, such as Figure 4 As shown, it includes: at least one processor, at least one memory and a communication interface; wherein the processor, the memory and the communication interface communicate with each other; the memory stores program instructions executed by the processor, and the processor calls the program instructions to execute the method as follows:

[0112] Acquire meteorological satellite remote sensing data in real time, and calculate the tropospheric zenith total delay grid product with the same temporal and spatial resolution based on the meteorological satellite remote sensing data;

[0113] Based on the tropospheric zenith total delay grid product, combined with the digital elevation model within the coverage of meteorological satellite remote sensing data, a tropospheric zenith total delay vertical lapse rate grid product with the same time resolution as the tropospheric zenith total delay is generated;

[0114] The vertical lapse rate grid product of the total tropospheric zenith delay is applied to the tropospheric delay correction of large altitude difference RTK.

[0115] In addition, when the logic instructions in the above-mentioned at least one memory are implemented in the form of a software functional unit and sold or used as an independent product, they are stored in a computer-readable storage medium. Based on this understanding, the technical solution of the present invention is essentially or partly in other words, the part that contributes to the prior art or part of the technical solution is embodied in the form of a software product, and the computer software product is stored in a storage medium, including several instructions for enabling a computer device (a personal computer, a server, or a network device) to perform all or part of the steps of the method described in each method embodiment of the present invention. The aforementioned storage medium includes: a U disk, a mobile hard disk, a read-only memory (ROM, Read-Only Memory), a random access memory (RAM, Random Access Memory), a disk or an optical disk, and various media for storing program codes.

[0116] The system embodiments described above are merely illustrative, wherein the units described as separate components are or are not physically separated, and the components shown as units are or are not physical units, located in one place, or distributed on multiple network units. Some or all of the modules are selected according to actual conditions to achieve the purpose of the solution of this embodiment. Those of ordinary skill in the art can understand and implement without creative effort.

[0117] An embodiment of the present invention further provides a non-transitory computer-readable storage medium, wherein the non-transitory computer-readable storage medium stores computer instructions, wherein the computer instructions enable the computer to execute the method as follows:

[0118] Acquire meteorological satellite remote sensing data in real time, and calculate the tropospheric zenith total delay grid product with the same temporal and spatial resolution based on the meteorological satellite remote sensing data;

[0119] Based on the tropospheric zenith total delay grid product, combined with the digital elevation model within the coverage of meteorological satellite remote sensing data, a tropospheric zenith total delay vertical lapse rate grid product with the same time resolution as the tropospheric zenith total delay is generated;

[0120] The vertical lapse rate grid product of the total tropospheric zenith delay is applied to the tropospheric delay correction of large altitude difference RTK.

[0121] In summary, the present invention calculates a tropospheric zenith total delay grid product of the same temporal and spatial resolution based on real-time meteorological satellite remote sensing data, generates a tropospheric zenith total delay vertical lapse rate grid product with the same temporal resolution as the tropospheric zenith total delay in combination with a digital elevation model within the coverage of the meteorological satellite remote sensing data according to the tropospheric zenith total delay grid product, and applies the tropospheric zenith total delay vertical lapse rate grid product to large-elevation-difference RTK tropospheric delay correction, thereby achieving large-scale, high-precision RTK tropospheric delay correction that is independent of ground measurement sites.

[0122] The present invention performs large altitude difference RTK tropospheric delay correction based on meteorological satellite remote sensing data, and has good time resolution and timeliness. At the same time, due to the large coverage of meteorological satellites, a large range of tropospheric zenith total delay vertical decrease rate products can be obtained for large altitude difference RTK tropospheric delay correction.

[0123] The present invention performs large altitude difference RTK tropospheric delay correction based on meteorological satellite remote sensing data, does not need to deploy measurement sites, has low cost and low data processing complexity.

[0124] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or replace some or all of the technical features therein with equivalents. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the technical solutions of the embodiments of the present invention.

Claims

1. A large altitude difference RTK tropospheric delay correction method based on meteorological satellite remote sensing, characterized in that: include: Acquire meteorological satellite remote sensing data in real time, and calculate tropospheric zenith total delay grid products of the same temporal and spatial resolution based on the meteorological satellite remote sensing data; Based on the tropospheric zenith total delay grid product and in combination with the digital elevation model within the coverage of meteorological satellite remote sensing data, a tropospheric zenith total delay vertical lapse rate grid product with the same time resolution as the tropospheric zenith total delay is generated, including: determining the coverage range and grid size of the tropospheric zenith total delay vertical lapse rate according to the coverage range of the tropospheric zenith total delay; Determine the grid point positions according to the coverage range and grid size of the tropospheric zenith total delay vertical lapse rate; calculate the tropospheric zenith total delay vertical lapse rate at each grid point position one by one, and generate a tropospheric zenith total delay vertical lapse rate grid product according to the tropospheric zenith total delay vertical lapse rate at all grid point positions; The vertical lapse rate grid product of the total tropospheric zenith delay is applied to the tropospheric delay correction of large altitude difference RTK.

2. The large height difference RTK tropospheric delay correction method based on meteorological satellite remote sensing according to claim 1 is characterized in that: Calculate the vertical decrease rate of the total delay of the tropospheric zenith at each grid point one by one, including: According to the global empirical tropospheric delay model, the tropospheric zenith total delay and the corresponding elevation value at the grid points within a preset distance range around the grid point position are obtained to form at least three triplets consisting of the elevation value, the tropospheric zenith total delay at the elevation value, and the empirical tropospheric delay at the elevation value; According to at least three of the triplets, a vertical decrease model of the total delay at the zenith of the troposphere is fitted to calculate the vertical decrease rate of the total delay at the zenith of the troposphere at the current grid point position.

3. The large height difference RTK tropospheric delay correction method based on meteorological satellite remote sensing according to claim 1 is characterized in that: The tropospheric zenith total delay vertical lapse rate grid product is applied to the large altitude difference RTK tropospheric delay correction, including: Get the approximate position of the RTK operation, and obtain the vertical decrease rate of the total delay at the zenith of the troposphere corresponding to the approximate position; The vertical decrease rate of the total delay at the zenith of the troposphere corresponding to the approximate position is substituted into the large height difference RTK positioning equation to obtain the coordinates of the mobile station.

4. The large height difference RTK tropospheric delay correction method based on meteorological satellite remote sensing according to claim 1 is characterized in that: The tropospheric zenith total delay grid products with the same temporal and spatial resolution are calculated based on the meteorological satellite remote sensing data, including: Obtaining atmospheric precipitable water according to the meteorological satellite remote sensing data; According to the atmospheric precipitable water, a tropospheric zenith wet delay is obtained; According to the tropospheric zenith wet delay and in combination with the tropospheric zenith static delay, the tropospheric zenith total delay based on meteorological satellite remote sensing data is obtained.

5. A large altitude difference RTK tropospheric delay correction device based on meteorological satellite remote sensing, characterized in that: include: The first main module is used to obtain meteorological satellite remote sensing data in real time, and calculate the tropospheric zenith total delay grid product with the same time and space resolution based on the meteorological satellite remote sensing data; The second main module is used to generate a tropospheric zenith total delay vertical lapse rate grid product with the same time resolution as the tropospheric zenith total delay based on the tropospheric zenith total delay grid product and in combination with a digital elevation model within the coverage of meteorological satellite remote sensing data, including: determining the coverage range and grid size of the tropospheric zenith total delay vertical lapse rate based on the coverage range of the tropospheric zenith total delay; Determine the grid point positions according to the coverage range and grid size of the tropospheric zenith total delay vertical lapse rate; calculate the tropospheric zenith total delay vertical lapse rate at each grid point position one by one, and generate a tropospheric zenith total delay vertical lapse rate grid product according to the tropospheric zenith total delay vertical lapse rate at all grid point positions; The third main module is used to apply the tropospheric zenith total delay vertical lapse rate grid product to the large altitude difference RTK tropospheric delay correction.

6. The large altitude difference RTK tropospheric delay correction device based on meteorological satellite remote sensing according to claim 5 is characterized in that: The third main module is also used to execute the following instructions: Get the approximate position of the RTK operation, and obtain the vertical decrease rate of the total delay at the zenith of the troposphere corresponding to the approximate position; The vertical decrease rate of the total delay at the zenith of the troposphere corresponding to the approximate position is substituted into the large height difference RTK positioning equation to obtain the coordinates of the mobile station.

7. An RTK positioning device, characterized in that: include: At least one processor, at least one memory and a communication interface; wherein the processor, memory and communication interface communicate with each other; The memory stores program instructions executed by the processor, and the processor calls the program instructions to execute the method according to any one of claims 1 to 4.

8. A non-transitory computer-readable storage medium, characterized in that: The non-transitory computer-readable storage medium stores computer instructions, which cause the computer to execute the method of any one of claims 1 to 4.

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