CN109827573B - Method, system and application for judging coordinate system - Google Patents
Method, system and application for judging coordinate system Download PDFInfo
- Publication number
- CN109827573B CN109827573B CN201711184207.9A CN201711184207A CN109827573B CN 109827573 B CN109827573 B CN 109827573B CN 201711184207 A CN201711184207 A CN 201711184207A CN 109827573 B CN109827573 B CN 109827573B
- Authority
- CN
- China
- Prior art keywords
- coordinate
- coordinate system
- base station
- coordinates
- reported
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Active
Links
Images
Abstract
The invention provides a method, a system and application for judging a coordinate system, wherein the method comprises the following steps: converting the coordinates reported by the user terminal according to different conversion formulas to obtain converted coordinates corresponding to each reference coordinate system one by one; calculating the distance from each converted coordinate to the coordinate of the base station, and taking the converted coordinate with the shortest distance as a target coordinate; taking a reference coordinate system corresponding to the target coordinate as a real coordinate system of the coordinate reported by the user terminal; the coordinate system type is one of a geographic coordinate system or a projected coordinate system. The method and the device are simple to implement, and can accurately judge the coordinate system adopted by the coordinates reported by the user terminal.
Description
Technical Field
The present invention relates to the field of positioning technologies, and in particular, to a method, a system, and an application for determining a coordinate system.
Background
Because of the encryption regulation of the mapping bureau to the internet map and the interest of each internet map, the coordinate system, the map tile organization mode, the slicing rule and the like of each internet map company are not as same as each other.
In the existing GPS personal positioning technology, GPS position information is acquired through a terminal, is converted into a coordinate system through a map APP carried by the terminal and then is reported to a platform interface, and is displayed on a map of the terminal. Therefore, the coordinates between the APPs are relatively independent, and information cannot be directly shared. For platforms and service providers such as operators, internet of things and the like, the technical difficulty of providing unified location service spanning multiple platforms and multiple coordinates exists.
In order to combine and analyze the coordinates acquired from different channels, firstly, a coordinate system judgment is performed on various coordinates. Due to the wide variety of coordinate systems, there is currently essentially no good way to identify the coordinates of a coordinate system that is completely uncertain. The following methods are commonly used for judging the coordinate system at present:
first, it is directly based on coordinate system information provided by the data provider. This method has the following problems: on one hand, because the data providers on which APP positioning depends are various in variety and the data disclosure degree of some data providers is not high, the coordinate system information of the data providers cannot be accurately acquired. On the other hand, part of the APPs are positioned according to the APP with the map of the system, and due to the fact that default maps set by users are different, coordinate types adopted by different users when the same APP is used can be different, and therefore the map positioning coordinate system cannot be accurately known.
Secondly, an SHP file based on ArcGIS (a GIS platform) contains a header XML file, and directly acquires information such as creation time, storage location, coordinate system, and the like stored therein. This method has the following problems: data depended on by APP positioning is from GPS position information reported during APP interaction, the APP interaction is completed by means of a data packet, and when the data packet is a network message, because the network message does not contain a coordinate system type, and does not contain an SHP file, an accurate coordinate system cannot be obtained.
Third, a coordinate system is determined from known coordinate points and corresponding coordinate positions. This method has the following problems: the drawbacks of the first method are known as follows: the types of the coordinate systems used by different APPs are different, and the coordinate systems used by different terminals of the same APP are possibly inconsistent, so that the historical data of different APPs or different terminals have almost no reference; meanwhile, the defects of the second method are known as follows: the GPS data source is based on the GPS position information reported in the user APP interaction, most of the information only contains the GPS position information and does not contain the corresponding coordinate point, so that no historical known coordinate point and corresponding coordinate position information exist.
Fourthly, judging the coordinate system to be a geographic coordinate system according to the coordinate system of [ -180,180], and judging the other coordinate system to be a projection coordinate system. Although the method can determine the type of the approximate coordinate system, the same geographic coordinate system is also classified into different coordinate systems such as WGS84, GCJ-02, BD-09, etc. in China, and the deviation between the coordinate systems is large, the maximum deviation is about 1200 meters, so the method cannot accurately obtain the specific coordinate system.
In addition, the current denoising method for GPS data generally adopts a trajectory denoising strategy: whether some points are noisy or not is judged according to a continuous segment of points. Generally, the deviation degree between the center of the point and the other points is calculated to determine whether the deviation degree exceeds a critical value. If the track formed by connecting the points is smooth, the points cannot be denoised.
The existing track denoising strategy needs to acquire a section of continuous points in the user history, in practical application, GPS information used and reported by the user is randomly reported according to needs (for example, a food APP is used for positioning nearby restaurants, a traffic APP is used for positioning nearby vehicles and the like), so that the GPS data of the user is sparse data, reference can not be made according to a section of continuous GPS information in the history, and the method needs a large amount of data and is difficult to implement.
Disclosure of Invention
The present invention provides a method, system and application for determining a coordinate system that overcomes or at least partially solves the above mentioned problems.
According to an aspect of the present invention, there is provided a method for determining a coordinate system, including:
s1, converting the coordinates reported by the user terminal according to different conversion formulas to obtain converted coordinates corresponding to each reference coordinate system one by one;
s2, calculating the distance between each converted coordinate and the coordinate of the base station, and taking the converted coordinate with the shortest distance as a target coordinate;
s3, taking a reference coordinate system corresponding to the target coordinate as a real coordinate system of the coordinate reported by the user terminal;
each conversion formula is used for converting a corresponding reference coordinate system into a coordinate system of coordinates of the base station, the reference coordinate system and the coordinate system of the base station belong to the same coordinate system type, and the coordinate system type is one of a geographic coordinate system or a projection coordinate system.
Preferably, the step S1 is preceded by:
determining a coordinate reported by a user terminal as a prepared coordinate, wherein a coordinate system of the prepared coordinate and a coordinate system of the base station coordinate belong to the same coordinate system type;
and taking the coordinate system of the base station coordinate and a certain number of coordinate systems belonging to the same coordinate system type as the coordinate system of the base station coordinate as each reference coordinate system, and obtaining the conversion formula for converting each reference coordinate system into the coordinate system of the base station coordinate.
Preferably, the method for calculating the distance from each converted coordinate to the coordinate of the base station in step S2 specifically includes:
when the coordinate system of the base station coordinate belongs to a geographic coordinate system, calculating the distance from the transformed coordinate to the base station according to the following formula:
wherein the converted coordinates are (A)lng,Alat) The base station coordinates are (B)lng,Blat)，DABAnd expressing the distance from the transformed coordinates to the base station, wherein PI is a circumferential ratio, and R is an equatorial radius.
Preferably, the step S3 specifically includes:
s3.1, obtaining a coordinate azimuth angle according to the base station coordinate and the target coordinate;
and S3.2, judging to acquire a reference coordinate system corresponding to the target coordinate as a real coordinate system of the coordinate reported by the user terminal by taking the condition that the coordinate azimuth is in the coverage direction of the base station corresponding to the base station coordinate and the distance from the target coordinate to the base station coordinate is in the coverage range of the base station corresponding to the base station coordinate.
Preferably, the step S3.1 specifically includes:
s3.1.1, acquiring the quadrant of the base station coordinate according to the position of the base station coordinate relative to the target coordinate;
s3.1.2, acquiring a coordinate azimuth angle according to the quadrant where the base station coordinate is located, the base station coordinate and the target coordinate;
the quadrant takes the target coordinate as an origin, the meridian is an X axis, and the latitude is a Y axis.
Preferably, said step 3.1.2 specifically comprises:
calculating a reference azimuth angle a of the base station coordinates and the target coordinates according to the following formula:
when the coordinates of the base station are in a first quadrant or a positive half shaft of a Y axis, the azimuth angle of the coordinates is A;
when the coordinates of the base station are in a second quadrant, the azimuth angle of the coordinates is 360 degrees + A;
when the base station coordinate is in the third quadrant, the fourth quadrant, or the negative half axis of the Y-axis, the coordinate azimuth angle is 180 ° + A.
Preferably, the step of determining the coordinates reported by the user terminal as the preliminary coordinates includes:
judging whether the coordinate system of the coordinates reported by the user terminal and the coordinate system of the coordinates of the base station belong to the same coordinate system type or not according to the definition of the coordinate system;
if the base station coordinates belong to the same coordinate system type, the coordinates reported by the user terminal are determined as the preparatory coordinates, if the base station coordinates do not belong to the same coordinate system type, the coordinates reported by the user terminal are converted into the coordinate system type which belongs to the same coordinate system type as the base station coordinates, and the converted coordinates are determined as the preparatory coordinates.
Preferably, the coordinate system of the coordinates of the base station is an international coordinate system WGS 84.
According to another aspect of the present invention, there is also provided a system for determining a coordinate system, including:
the coordinate conversion module is used for converting the coordinates reported by the user terminal according to different conversion formulas to obtain converted coordinates corresponding to each reference coordinate system one by one;
the target coordinate module is used for calculating the distance from each converted coordinate to the coordinate of the base station, and taking the converted coordinate with the shortest distance as a target coordinate;
a coordinate system judging module, configured to use a reference coordinate system corresponding to the target coordinate as a real coordinate system of a coordinate reported by the user terminal;
each conversion formula is used for converting a corresponding reference coordinate system into a coordinate system of coordinates of the base station, the reference coordinate system and the coordinate system of the base station belong to the same coordinate system type, and the coordinate system type is one of a geographic coordinate system or a projection coordinate system.
According to another aspect of the embodiment of the present invention, there is also provided an application of the method for determining a coordinate system as described above in GPS data denoising.
According to the judging method, the judging system and the judging application of the coordinate system, the coordinate system on which the coordinate reported by the user terminal depends is unknown, so that the embodiment of the invention firstly supposes the coordinate reported by the user terminal to be various coordinate systems, and then obtains the converted coordinate corresponding to each coordinate system according to the method of converting different coordinate systems to the coordinate system adopted by the base station coordinate; calculating the distance from each converted coordinate to the coordinate of the base station, and taking the converted coordinate with the shortest distance as a target coordinate; and taking the reference coordinate system corresponding to the target coordinate as a real coordinate system of the coordinate reported by the user terminal. The method for judging the coordinate system is simple to implement and can accurately judge the coordinate type.
Drawings
FIG. 1 is a schematic illustration of an implementation environment according to an embodiment of the present invention;
FIG. 2 is a flowchart illustrating a determining method according to an embodiment of the invention;
FIG. 3 is a functional block diagram of a determination system according to an embodiment of the present invention;
FIG. 4 is a schematic diagram of the distribution of distances between a Shanghai city 4G base station and its nearest base station;
fig. 5 is a schematic diagram of the distribution of distances between a 4G base station in shanghai city and its nearest 4 base stations.
Detailed Description
The following detailed description of embodiments of the present invention is provided in connection with the accompanying drawings and examples. The following examples are intended to illustrate the invention but are not intended to limit the scope of the invention.
In order to overcome the above problems in the prior art, embodiments of the present invention provide a method for determining a coordinate system. The embodiments of the present invention mainly describe determining a coordinate system of coordinates reported by a user terminal. The coordinate system types are mainly divided into a geographical coordinate system and a projection coordinate system, wherein the geographical coordinate system comprises an international coordinate system (WGS84 coordinate system), a mars coordinate system (GCJ-02 coordinate system), a map bar coordinate system (MapBar coordinate system), a dog searching coordinate system (sogou coordinate system) and a hundredth coordinate system (BD-09 coordinate system); the projection coordinate system includes a hundred degree projection coordinate system and a web mercator projection coordinate system. Not only can the geographic coordinate system and the projection coordinate system be mutually converted according to the existing conversion formula, but also two coordinate systems belonging to the same type can be arbitrarily converted. The specific conversion method or conversion formula belongs to the common knowledge in the field, for example, https:// www.biaodianfu.com/coordinate-system html introduces the specific method for map longitude and latitude and coordinate system conversion, and the embodiment of the present invention is not described again.
The user terminal (abbreviated as UE in english) in the embodiments of the present invention may include various internet of things devices, smart grid devices, handheld devices, vehicle-mounted devices, wearable devices, computing devices, or other processing devices connected to a wireless modem, which have a wireless communication function.
The base station involved in the embodiment of the present invention is a device deployed in a radio access network to provide a wireless communication function for a UE, and may include various forms of macro base stations, micro base stations, relay stations, access points, and the like. In systems using different radio access technologies, the names of devices that function as base stations may differ.
Fig. 1 is a schematic diagram illustrating an implementation environment according to various embodiments of the present invention, where the various embodiments of the present invention mainly describe that a coordinate system of coordinates reported by a UE is determined, but in a specific application of the embodiments of the present invention, a plurality of UEs and a plurality of 4G base stations (enbs) may exist, and an interaction manner between the UEs and the enbs is the same as that described in the embodiments of the present invention.
As shown in fig. 1, an eNB101 communicates with UEs 102, 103, 104, 105 through a wireless network, where the UE may be a mobile communication device such as 102, or a portable smart device such as 103, or smart internet of things terminals such as 104 and 105, such as a smart grid device, and so on. It should be understood that the UE category shown in fig. 1 is only exemplary, and the inventive concept embodied in the embodiments of the present invention can be applied to any method for determining a coordinate system using coordinates uploaded by a wireless network.
Fig. 2 is a schematic flowchart of a method for determining a coordinate system according to an embodiment of the present invention, where the embodiment describes a method for determining a coordinate system of coordinates uploaded by a user equipment according to the present invention, and the method includes:
s101, converting the coordinates reported by the user terminal according to different conversion formulas to obtain converted coordinates corresponding to each reference coordinate system one by one. Each transformation formula is used for transforming a corresponding one of the reference coordinate systems to a coordinate system of the base station coordinates. The reference coordinate system is a coordinate system of the same type of coordinate system as the coordinate system of the base station.
It should be noted that, because the coordinate system on which the coordinates reported by the user terminal depend is unknown, in the embodiment of the present invention, the coordinates reported by the user terminal are assumed to be various coordinate systems, and then the converted coordinates corresponding to each coordinate system are obtained according to the method of converting the different coordinate systems to the coordinate system adopted by the base station coordinates.
It should be noted that the imaginary coordinate systems are called reference coordinate systems, and the reference coordinate systems and the coordinate systems of the base stations belong to the same coordinate system type, for example, the coordinate system of the base station is a hundredth degree coordinate system, i.e. a geographical coordinate system, and then the reference coordinate systems should also belong to the geographical coordinate systems, such as GCJ-02, BD-09, WGS84, etc.
In a specific application, a base station coordinate system is BD-09, coordinates reported by a user terminal are converted according to a conversion formula for converting GCJ-02 to BD-09, and converted coordinates corresponding to GCJ-02 are obtained and are called as coordinates 1; converting according to a conversion formula from WGS84 to BD-09 to obtain a converted coordinate corresponding to WGS84, namely coordinate 2; and converting according to a conversion formula for converting the dog searching coordinate system into the BD-09 to obtain converted coordinates corresponding to the dog searching coordinate system, namely coordinates 3, wherein the coordinates 1, 2 and 3 are the converted coordinates of each reference coordinate system in one-to-one correspondence obtained in the step S101.
And S102, calculating the distance from each converted coordinate to the coordinate of the base station, and taking the converted coordinate with the shortest distance as a target coordinate.
And S103, taking the reference coordinate system corresponding to the target coordinate as a real coordinate system of the coordinate reported by the user terminal.
It should be noted that, in order to determine the real coordinate system of the coordinates reported by the user terminal, the embodiment of the present invention determines the real coordinate system by using the distance from the converted coordinates to the coordinates of the base station. The reason is that firstly, the closest base station is selected when the user terminal reports the message, secondly, because each coordinate system actually carries out proper deviation processing on the basic coordinate, if a correct conversion method is adopted, the natural deviation amount does not exist, and by calculating the distance between the converted coordinate and the base station coordinate, the coordinate converted according to which coordinate system conversion formula is closest to the base station coordinate can be known, obviously, the conversion formula used by the closest coordinate is correct, and the coordinate system corresponding to the conversion formula is also the real coordinate system.
The embodiment of the invention overcomes the problem of poor practicability and feasibility of the method for judging the coordinate system in the prior art, and has the advantages of simple realization and accurate judgment.
On the basis of the above embodiments, step S101 further includes:
and determining the coordinates reported by the user terminal as preparatory coordinates, wherein the coordinate system of the preparatory coordinates and the coordinate system of the base station coordinates belong to the same coordinate system type.
And taking the coordinate system of the base station coordinate and a certain number of coordinate systems belonging to the same coordinate system type as the coordinate system of the base station coordinate as each reference coordinate system, and obtaining the conversion formula for converting each reference coordinate system into the coordinate system of the base station coordinate.
It should be noted that the purpose of determining the preliminary coordinates is to convert the coordinates reported by the ue into a coordinate type that belongs to the same coordinate type as the coordinate system of the base station coordinates. If the coordinate system of the coordinates reported by the user terminal and the coordinate system of the coordinates of the base station do not belong to one coordinate system type, the coordinates reported by the user terminal cannot be directly converted into the coordinate system of the coordinates of the base station.
On the basis of the foregoing embodiments, the method for calculating the distance from each converted coordinate to the base station coordinate in step S102 specifically includes:
when the coordinate system of the base station coordinate belongs to the geographic coordinate system, calculating the distance from the transformed coordinate to the base station according to the following formula:
wherein the converted coordinates are (A)lng,Alat) The base station coordinates are (B)lng,Blat)，DABAnd expressing the distance from the transformed coordinates to the base station, wherein PI is a circumferential ratio, and R is an equatorial radius.
It should be noted that, the embodiment of the present invention only exemplifies the distance from the transformed coordinates to the base station when the coordinates of the base station are the geographic coordinate system, and when the coordinates of the base station and the transformed coordinates are the projection coordinate system, the distance may be obtained by other existing methods, and the present invention is not limited specifically.
It should also be noted that, since the geographic coordinate system is a spherical coordinate system in which the point and plane locations are represented by latitude and longitude, and the coordinate form of one geographic coordinate system is simple, it is also convenient when calculating the distance.
In practical application, the data packet reported by the user terminal includes the coordinates requested by the user and the base station information relied on by the user terminal, and the base station coordinates can be obtained through the base station information. The coordinates requested by the user can be divided into two types, one type is the current coordinates of the user terminal, for example, when a mobile phone shopping APP is opened, a dialog box of 'requesting to locate your current address' is often popped up, if the request is approved, the current coordinates are reported by the user terminal, and at this time, the base station on which the user terminal depends is also the base station closest to the user terminal; another type is not the current coordinate of the user terminal, for example, a mobile phone map is opened at point a, and the position of point B is desired to be obtained, and what the user terminal reports is no longer the current coordinate but the coordinates of other places, so in this case, it is obvious that the base station on which the coordinates of other places depend is likely to be different from the base station corresponding to the user terminal in the data packet, and then the risk of low accuracy exists in the coordinate system determined directly by the nearest distance.
Therefore, on the basis of the foregoing embodiments, step S103 specifically includes:
s3.1, obtaining a coordinate azimuth angle according to the base station coordinate and the target coordinate;
and S3.2, judging to obtain a reference coordinate system corresponding to the target coordinate as a real coordinate system of the coordinate reported by the user terminal by taking the condition that the coordinate azimuth is in the coverage direction of the base station corresponding to the base station coordinate and the distance from the target coordinate to the base station coordinate is in the coverage range of the base station corresponding to the base station coordinate.
It should be noted that, in this embodiment, it is determined whether the target coordinate corresponds to the base station in the data packet reported by the user terminal according to the coverage area and the coverage direction of the base station, and the target coordinate is used as a requirement for determining reliability of the coordinate system. If the coverage direction or the coverage range is not in accordance, it indicates that the coordinates reported by the user terminal are not the current position of the user terminal, and therefore the real coordinate system cannot be continuously judged.
On the basis of the above embodiments, step S3.1 specifically includes:
s3.1.1, acquiring the quadrant of the base station coordinate according to the position of the base station coordinate relative to the target coordinate; the quadrant takes the target coordinate as the origin, the longitude as the X axis and the latitude as the Y axis
S3.1.2, obtaining the coordinate azimuth angle according to the quadrant of the base station coordinate, the base station coordinate and the target coordinate.
As can be understood by those skilled in the art, the origin is in the positive X-axis direction from east, in the negative X-axis direction from west, in the positive Y-axis direction from north, in the negative Y-axis direction from south, i.e. the first quadrant of the northeast area of the origin, the northwest area of the origin is the second quadrant, the southwest area of the origin is the third quadrant, and the southeast area of the origin is the fourth quadrant.
On the basis of the foregoing embodiment, step S3.1.2 specifically includes:
calculating a reference azimuth angle A of the base station coordinates and the target coordinates according to the following formula:
when the coordinates of the base station are in a first quadrant or a positive half shaft of a Y axis, the azimuth angle of the coordinates is A;
when the coordinates of the base station are in the second quadrant, the azimuth angle of the coordinates is 360 degrees + A;
when the base station coordinates are in the third quadrant, the fourth quadrant, or the negative half axis of the Y-axis, the coordinate azimuth is 180 ° + a.
On the basis of the above embodiments, the step of determining the coordinates reported by the user terminal as the preliminary coordinates includes:
judging whether the coordinate system of the coordinates reported by the user terminal and the coordinate system of the coordinates of the base station belong to the same coordinate system type or not according to the definition of the coordinate system;
in specific application, the type of the coordinate system can be distinguished by the definition of the coordinate system, taking the sea city as an example, the range of the projection coordinate system in dimension (X axis) is (13358484-13692446), the range of the progress (Y axis) is (3481989-3871817), and the range of the geographic coordinate system in coordinate system is very intuitive and is: -180,180], it is obvious that the coordinate system type of the coordinates reported by the user terminal can be easily distinguished by the format of the coordinates.
If the coordinates of the user terminal and the coordinates of the base station belong to the same coordinate system type, the coordinates reported by the user terminal are determined as the prepared coordinates, if the coordinates do not belong to the same coordinate system type, the coordinates reported by the user terminal are converted into the coordinates which belong to the same coordinate system type as the coordinates of the base station, and the converted coordinates are determined as the prepared coordinates.
It should be noted that the same type of coordinate system is the basis for implementing the present invention, and therefore, through the above determination process, a basis is provided for subsequently calculating the transformed coordinates and the coordinates of the base station. For example, if the coordinates reported by the user terminal and the coordinates of the base station both belong to a geographic coordinate system, the coordinates reported by the user terminal are determined as preliminary coordinates, and if the coordinates reported by the user terminal are based on a projection coordinate system and the coordinates of the base station are based on the geographic coordinate system, the coordinates reported by the user terminal need to be transformed according to a formula for transforming the projection coordinate system into the geographic coordinate system, and the transformed coordinates are determined as preliminary coordinates.
In addition to the above embodiments, the coordinate system of the base station coordinate system is the international coordinate system WGS 84. The international coordinate system WGS84 is the most widely used coordinate system for positioning base stations in China, and is convenient for positioning and coordinate system conversion.
According to another aspect of the present invention, there is also provided a system for determining a coordinate system, as shown in fig. 3, where the system is used to determine a coordinate system adopted by a coordinate reported by a user terminal in the foregoing embodiments, and therefore, descriptions and definitions in the determination methods in the foregoing embodiments may be used for understanding each execution module in the embodiments of the present invention.
As shown in the figure, the system for determining the coordinate system includes:
the coordinate conversion module 201 is configured to convert the coordinates reported by the user terminal according to different conversion formulas, so as to obtain converted coordinates corresponding to each reference coordinate system one to one. The reference coordinate system is a coordinate system of the same type of coordinate system as the coordinate system of the base station.
It should be noted that, because the coordinate system on which the coordinates reported by the user terminal depend is unknown, the coordinate conversion module 201 of the embodiment of the present invention first assumes the coordinates reported by the user terminal as various coordinate systems, and then obtains the converted coordinates corresponding to each coordinate system according to the method of converting the different coordinate systems to the coordinate system adopted by the base station coordinates.
It should be noted that the imaginary coordinate systems are called reference coordinate systems, and the reference coordinate systems and the coordinate systems of the base stations belong to the same coordinate system type, for example, the coordinate system of the base station is a hundredth degree coordinate system, i.e. a geographical coordinate system, and then the reference coordinate systems should also belong to the geographical coordinate systems, such as GCJ-02, BD-09, WGS84, etc.
In a specific application, a base station coordinate system is BD-09, coordinates reported by a user terminal are converted according to a conversion formula for converting GCJ-02 to BD-09, and converted coordinates corresponding to GCJ-02 are obtained and are called as coordinates 1; converting according to a conversion formula from WGS84 to BD-09 to obtain a converted coordinate corresponding to WGS84, namely coordinate 2; and converting according to a conversion formula for converting the dog searching coordinate system into the BD-09 to obtain converted coordinates corresponding to the dog searching coordinate system, namely coordinates 3, wherein the coordinates 1, 2 and 3 are the converted coordinates of each reference coordinate system in one-to-one correspondence obtained in the step S101.
A target coordinate module 202, configured to calculate a distance from each converted coordinate to a base station coordinate, and use the converted coordinate with the shortest distance as a target coordinate;
and the coordinate system judging module 203 is configured to use a reference coordinate system corresponding to the target coordinate as a real coordinate system of the coordinate reported by the user terminal.
It should be noted that, in order to determine the real coordinate system of the coordinates reported by the user terminal, the coordinate system determining module 203 of the embodiment of the present invention determines the real coordinate system by using the distance from the converted coordinates to the coordinates of the base station. The reason is that firstly, the closest base station is selected when the user terminal reports the message, secondly, because each coordinate system actually carries out proper deviation processing on the basic coordinate, if a correct conversion method is adopted, the natural deviation amount does not exist, and by calculating the distance between the converted coordinate and the base station coordinate, the coordinate converted according to which coordinate system conversion formula is closest to the base station coordinate can be known, obviously, the conversion formula used by the closest coordinate is correct, and the coordinate system corresponding to the conversion formula is also the real coordinate system.
On the basis of the above embodiment, the coordinate system determination module specifically includes:
the coordinate azimuth angle unit is used for obtaining a coordinate azimuth angle according to the base station coordinate and the target coordinate;
and the judging unit is used for judging a real coordinate system of the coordinate reported by the user terminal by taking the condition that the coordinate azimuth is in the coverage direction of the base station corresponding to the base station coordinate and the distance from the target coordinate to the base station coordinate is in the coverage range of the base station corresponding to the base station coordinate.
It should be noted that, the coordinate system determining module of this embodiment determines whether the target coordinate corresponds to the base station in the data packet reported by the user terminal according to the coverage area and the coverage direction of the base station, and uses the target coordinate as a requirement for determining reliability of the coordinate system. If the coverage direction or the coverage range is not in accordance, it indicates that the coordinates reported by the user terminal are not the current position of the user terminal, and therefore the real coordinate system cannot be continuously judged.
The method provided by the embodiment of the invention can be applied to a GPS denoising scene. The specific application method comprises the following steps: the target coordinates are obtained according to the method described in the above embodiment, and in combination with the known coverage distance and direction information of the base station, if the target coordinates are not within the range of the base station or not within the coverage direction of the base station, the target coordinates are noise and need to be deleted.
It should be noted that the method for judging the coordinate system in combination with the coverage information of the base station, provided by each of the above embodiments of the present invention, can solve the problem that the position reported by the terminal is not an actual position, that is, implement the denoising of the GPS information.
The rationality of the invention is analyzed below with reference to a specific example.
The coordinates of the base station in this embodiment adopt a WGS84 coordinate system, which belongs to a geographical coordinate system.
Step 1, judging whether the coordinate system is a geographical coordinate system or not
Judging the type of the coordinate system adopted by the UE reporting coordinates according to the coordinate system definition, such as: the coordinate point is judged to be a geographical coordinate system at-180,180; if the non-geographic coordinates are converted to geographic coordinates according to an existing conversion formula. For example, the hundredth degree projection coordinate can be distinguished according to the range of the Y value, and the coordinate reported by the UE is determined as the preparation coordinate.
Step 2, converting the prepared coordinates into WGS84 coordinates according to each reference coordinate system conversion formula
In this step, coordinate position information of unknown specific coordinate types is converted into WGS84 coordinates in a unified manner, specifically, according to the conventional techniques of converting coordinate types such as GCJ-02, BD-09, and WGS84 into WGS84 coordinates.
Step 3, calculating the distance between the transformed coordinates and the coordinates of the base station
The distance between the converted coordinate point and the coordinates of the base station (WGS84) and the direction angle with respect to the position of the base station are calculated.
Assume transformed A point coordinates (A)lng,Alat) Base station B Point coordinates (B)lng,Blat) The distance between the two is as follows:
wherein D isABAnd expressing the distance from the transformed coordinates to the base station, wherein PI is a circumferential ratio, and R is an equatorial radius.
Step 4, calculating the coordinate azimuth angle between the converted coordinates and the coordinates of the base station
Calculating a reference azimuth angle A:
when the point B is in the first quadrant and the positive semi-axis of the Y axis, the coordinate azimuth angle is A;
when B is in the second quadrant, the coordinate azimuth angle is 360 degrees + A;
when B is in the third quadrant and the negative half axis of Y axis, the coordinate azimuth angle is 180 + A.
And 5, taking the converted coordinate with the shortest distance as a target coordinate, judging and obtaining a reference coordinate system corresponding to the target coordinate as a real coordinate system of the coordinate reported by the user terminal according to the fact that the azimuth angle of the coordinate is in the coverage direction of the base station corresponding to the base station coordinate, and the distance from the target coordinate to the base station coordinate is in the coverage range of the base station corresponding to the base station coordinate. And if the target coordinate is not in the coverage range and the coverage direction, the judgment type of the original coordinate system is wrong or the actual position of the non-UE at the reported position is represented.
Fig. 4 shows a distribution of distances between the shanghai city 4G base stations and their nearest base stations, and fig. 5 shows a distribution of distances between the shanghai city 4G base stations and their nearest 4 base stations. As can be seen from fig. 4 and 5, the distance between the base stations is 900 meters, and there are other base stations within 500 meters near about 89% of the base stations, so the coverage area of the base stations can be estimated to be 450 meters or less.
Table 1 shows the distance between the reference coordinate systems calculated in this embodiment.
| Distance (rice) | WGS84 | GCJ-02 | BD-09 |
| |
0 | 480 | 1200 |
| GCJ-02 | 480 | 0 | 940 |
| BD-09 | 1200 | 940 | 0 |
TABLE 1 distance table of phase differences between reference coordinate systems
As can be seen from table 1, the distance deviation between the coordinate systems is approximately 480-.
The above-described embodiments of the apparatus are merely illustrative, and the units described as separate parts may or may not be physically separate, and the parts displayed as units may or may not be physical units, may be located in one place, or may be distributed on a plurality of network units. Some or all of the modules may be selected according to actual needs to achieve the purpose of the solution of the present embodiment. One of ordinary skill in the art can understand and implement it without inventive effort.
Through the above description of the embodiments, those skilled in the art will clearly understand that each embodiment can be implemented by software plus a necessary general hardware platform, and certainly can also be implemented by hardware. With this understanding in mind, the above-described technical solutions may be embodied in the form of a software product, which can be stored in a computer-readable storage medium, such as ROM/RAM, magnetic disk, optical disk, etc., and includes instructions for causing a computer device (which may be a personal computer, a server, or a network device, etc.) to execute the methods of the various embodiments or some parts of the embodiments.
Finally, it should be noted that: the above examples are only intended to illustrate the technical solution of the present invention, but not to limit it; although the present invention has been described in detail with reference to the foregoing embodiments, it will be understood by those of ordinary skill in the art that: the technical solutions described in the foregoing embodiments may still be modified, or some technical features may be equivalently replaced; and such modifications or substitutions do not depart from the spirit and scope of the corresponding technical solutions of the embodiments of the present invention.
Claims (10)
1. A method for determining a coordinate system, comprising:
s1, converting the coordinates reported by the user terminal according to different conversion formulas to obtain converted coordinates corresponding to each reference coordinate system one by one;
s2, calculating the distance between each converted coordinate and the coordinate of the base station, and taking the converted coordinate with the shortest distance as a target coordinate;
s3, taking a reference coordinate system corresponding to the target coordinate as a real coordinate system of the coordinate reported by the user terminal;
each conversion formula is used for converting a corresponding reference coordinate system into a coordinate system of coordinates of the base station, the reference coordinate system and the coordinate system of the base station belong to the same coordinate system type, and the coordinate system type is one of a geographic coordinate system or a projection coordinate system.
2. The method according to claim 1, wherein the step S1 is preceded by:
determining a coordinate reported by a user terminal as a prepared coordinate, wherein a coordinate system of the prepared coordinate and a coordinate system of the base station coordinate belong to the same coordinate system type;
and taking the coordinate system of the base station coordinate and a certain number of coordinate systems belonging to the same coordinate system type as the coordinate system of the base station coordinate as each reference coordinate system, and obtaining the conversion formula for converting each reference coordinate system into the coordinate system of the base station coordinate.
3. The method as claimed in claim 1, wherein the step S2 of calculating the distance from each converted coordinate to the coordinate of the base station specifically includes:
when the coordinate system of the base station coordinate belongs to a geographic coordinate system, calculating the distance from the transformed coordinate to the base station according to the following formula:
wherein the converted coordinates are (A)lng,Alat) The base station coordinates are (B)lng,Blat)，DABAnd expressing the distance from the transformed coordinates to the base station, wherein PI is a circumferential ratio, and R is an equatorial radius.
4. The method according to claim 1 or 3, wherein the step S3 specifically includes:
s3.1, obtaining a coordinate azimuth angle according to the base station coordinate and the target coordinate;
and S3.2, judging to acquire a reference coordinate system corresponding to the target coordinate as a real coordinate system of the coordinate reported by the user terminal by taking the condition that the coordinate azimuth is in the coverage direction of the base station corresponding to the base station coordinate and the distance from the target coordinate to the base station coordinate is in the coverage range of the base station corresponding to the base station coordinate.
5. The method according to claim 4, wherein the step S3.1 specifically includes:
s3.1.1, acquiring the quadrant of the base station coordinate according to the position of the base station coordinate relative to the target coordinate;
s3.1.2, acquiring a coordinate azimuth angle according to the quadrant where the base station coordinate is located, the base station coordinate and the target coordinate;
the quadrant takes the target coordinate as an origin, the meridian is an X axis, and the latitude is a Y axis.
6. The method according to claim 5, wherein the step S3.1.2 specifically includes:
calculating a reference azimuth angle a of the base station coordinates and the target coordinates according to the following formula:
when the coordinates of the base station are in a first quadrant or a positive half shaft of a Y axis, the azimuth angle of the coordinates is A;
when the coordinates of the base station are in a second quadrant, the azimuth angle of the coordinates is 360 degrees + A;
when the base station coordinate is in the third quadrant, the fourth quadrant, or the negative half axis of the Y-axis, the coordinate azimuth angle is 180 ° + A.
7. The method as claimed in claim 2, wherein the step of determining the coordinates reported by the ue as the preliminary coordinates comprises:
judging whether the coordinate system of the coordinates reported by the user terminal and the coordinate system of the coordinates of the base station belong to the same coordinate system type or not according to the definition of the coordinate system;
if the base station coordinates belong to the same coordinate system type, the coordinates reported by the user terminal are determined as the preparatory coordinates, if the base station coordinates do not belong to the same coordinate system type, the coordinates reported by the user terminal are converted into the coordinate system type which belongs to the same coordinate system type as the base station coordinates, and the converted coordinates are determined as the preparatory coordinates.
8. The method of claim 1, wherein the coordinates of the base station are international coordinates WGS 84.
9. A system for determining a coordinate system, comprising:
the coordinate conversion module is used for converting the coordinates reported by the user terminal according to different conversion formulas to obtain converted coordinates corresponding to each reference coordinate system one by one;
the target coordinate module is used for calculating the distance from each converted coordinate to the coordinate of the base station, and taking the converted coordinate with the shortest distance as a target coordinate;
a coordinate system judging module, configured to use a reference coordinate system corresponding to the target coordinate as a real coordinate system of a coordinate reported by the user terminal;
each conversion formula is used for converting a corresponding reference coordinate system into a coordinate system of coordinates of the base station, the reference coordinate system and the coordinate system of the base station belong to the same coordinate system type, and the coordinate system type is one of a geographic coordinate system or a projection coordinate system.
10. Use of the method of claim 4 for determining a coordinate system for denoising GPS data.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201711184207.9A CN109827573B (en) | 2017-11-23 | 2017-11-23 | Method, system and application for judging coordinate system |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201711184207.9A CN109827573B (en) | 2017-11-23 | 2017-11-23 | Method, system and application for judging coordinate system |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN109827573A CN109827573A (en) | 2019-05-31 |
| CN109827573B true CN109827573B (en) | 2020-11-13 |
Family
ID=66859556
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201711184207.9A Active CN109827573B (en) | 2017-11-23 | 2017-11-23 | Method, system and application for judging coordinate system |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN109827573B (en) |
Families Citing this family (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN111107485B (en) * | 2019-12-03 | 2021-07-06 | 浙江大学 | Positioning base station selection method |
| CN111221014A (en) * | 2020-01-07 | 2020-06-02 | 南京华苏科技有限公司 | OTT data position-based intelligent deviation rectifying method and device |
| CN111858798A (en) * | 2020-06-24 | 2020-10-30 | 广东邦盛北斗科技股份公司 | Method for automatically identifying track data coordinate system, method for displaying track of positioning product on map, storage medium and electronic equipment |
| CN111988843B (en) * | 2020-08-12 | 2022-04-01 | 中国计量大学 | Base station self-calibration method |
Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN1399200A (en) * | 2001-07-25 | 2003-02-26 | 日本电气株式会社 | Method and system for converting positioning signal in different coordinate system to specified coordinate system |
| JP2011232444A (en) * | 2010-04-26 | 2011-11-17 | Ntt Docomo Inc | Coordinate conversion device, coordinate conversion method and program |
| CN105160191A (en) * | 2015-09-16 | 2015-12-16 | 广州市城市规划勘测设计研究院 | Plane coordinate conversion method and apparatus |
| CN105160197A (en) * | 2015-09-23 | 2015-12-16 | 湖北省基础地理信息中心 | Comprehensive geographical spatial data coordinate conversion method and system |
| CN106204734A (en) * | 2015-04-30 | 2016-12-07 | 浙江宇视科技有限公司 | The map integrated based on multi-source map generates method and device |
Family Cites Families (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| KR101544315B1 (en) * | 2014-04-23 | 2015-08-13 | 서울대학교산학협력단 | Efficient three-dimensional localization method using trilateration in wireless network and recording medium having application program recorded thereon |
-
2017
- 2017-11-23 CN CN201711184207.9A patent/CN109827573B/en active Active
Patent Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN1399200A (en) * | 2001-07-25 | 2003-02-26 | 日本电气株式会社 | Method and system for converting positioning signal in different coordinate system to specified coordinate system |
| JP2011232444A (en) * | 2010-04-26 | 2011-11-17 | Ntt Docomo Inc | Coordinate conversion device, coordinate conversion method and program |
| CN106204734A (en) * | 2015-04-30 | 2016-12-07 | 浙江宇视科技有限公司 | The map integrated based on multi-source map generates method and device |
| CN105160191A (en) * | 2015-09-16 | 2015-12-16 | 广州市城市规划勘测设计研究院 | Plane coordinate conversion method and apparatus |
| CN105160197A (en) * | 2015-09-23 | 2015-12-16 | 湖北省基础地理信息中心 | Comprehensive geographical spatial data coordinate conversion method and system |
Non-Patent Citations (2)
| Title |
|---|
| ArcGIS中的坐标系统及投影变换应用研究;乔金海等;《城市道桥与防洪》;20111215(第12期);第162-164页 * |
| 一种工程中实用的WGS-84到BJ-54坐标系转换方法;刘缨;《现代电子技术》;20051215(第23期);第85-87页 * |
Also Published As
| Publication number | Publication date |
|---|---|
| CN109827573A (en) | 2019-05-31 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN109827573B (en) | Method, system and application for judging coordinate system | |
| JP5389275B2 (en) | Location filtering using country codes | |
| US9723585B2 (en) | Method and apparatus for position determination in a cellular communications system | |
| CN107289925B (en) | Method and device for drawing user track | |
| CN104010364B (en) | For determining the method and system in the geographical location of the estimation of base station | |
| CN107466043B (en) | Method and equipment for determining azimuth angle of base station antenna | |
| CN105611568B (en) | A method of LTE terminal position is accurately positioned based on MRO measurement report | |
| CN102918875B (en) | Use the positioning and location-based service of urban addresses information | |
| CN105188135B (en) | Method of locating terminal and system, target terminal and location-server | |
| US20170371024A1 (en) | Supporting a collaborative collection of data | |
| CN104776842B (en) | A kind of method and device obtaining point of interest location information | |
| CN103096464B (en) | Single base station user method of locating terminal and system | |
| CN106919567B (en) | Method and device for processing POI (Point of interest) address | |
| CN104581931A (en) | Positioning method, device and terminal | |
| CN112312301B (en) | User terminal positioning method, device, equipment and computer storage medium | |
| CN108351421A (en) | Localization method, base station in mobile network and mobile terminal | |
| CN104144493A (en) | Positioning method, positioning system and a base station positioning platform | |
| CN101815350B (en) | Method for positioning user equipment and user equipment therefor | |
| CN109996178B (en) | Positioning method, apparatus, device and medium | |
| CN104469940A (en) | Method and system for locating wireless terminal equipment based on wireless router | |
| CN104050869B (en) | GIS map covering is layouted response method and system | |
| CN102540225A (en) | Programmable smart mobile phone based CORS (continuous operational reference system) positioning implementing method | |
| CN107580297B (en) | Meteorological data transmission method and accurate push system based on meteorological base stations and mobile terminals of various regions | |
| CN104023392B (en) | The method and apparatus for determining the position of WAP | |
| CN106488556B (en) | method and device for correcting offset of positioning signal |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| GR01 | Patent grant | ||
| GR01 | Patent grant |