A method, apparatus and system for emergency alerting

Abstract

This invention discloses an encoding and decoding method, system, and device for emergency alarms. The encoding method includes: acquiring the latitude and longitude coordinates of a target location; determining the latitude and longitude grid index values ​​of the grid cell to which the coordinates belong, as well as the total number of grid cells along the longitude direction, based on globally unified geographic grid division parameters; performing a dimensionality reduction mapping operation on the two-dimensional grid index to generate a one-dimensional linear index value; and performing modulo operation and character formatting on the one-dimensional linear index value based on a preset target character length to obtain a pure numeric short code. The decoding method includes: receiving the pure numeric short code and the city name provided by the alarm caller; performing a modulo inverse operation on the pure numeric short code to obtain multiple linear index candidate values; performing a dimensionality increase mapping operation on each linear index candidate value to restore it to a latitude and longitude candidate index value; determining the latitude and longitude coordinates of the candidate locations based on the maximum positioning error, and outputting a candidate point list. This invention generates a pure numeric short code of the target character length, providing user-friendly voice transmission without letter confusion, and offering fast and accurate decoding. It can be widely applied to scenarios such as 110, 120, 119 emergency calls and mountain rescue.

Description

Technical Field

[0001] This invention relates to geolocation coding technology, and more particularly to a coding and decoding method, apparatus and system for emergency alarms. Background Technology

[0002] In emergency situations such as police calls (110, 119, 120) and mountain rescues, callers often struggle to accurately describe their location due to unfamiliar surroundings, anxiety, or a lack of clear landmarks, leading to significant delays in rescue responses. While existing technologies have proposed various location description and positioning schemes, they still suffer from the following shortcomings: (1) Limitations of natural language description: It relies on the alarm person's knowledge of address information such as street and house number, which is basically ineffective in the wild, suburbs or unfamiliar environment.

[0003] (2) Physical identification coding scheme: Schemes represented by street light pole coding require the pre-deployment of unique numbers on a large number of facilities, resulting in limited coverage, high maintenance costs, and inability to be used in areas where no identification has been deployed. Such schemes are essentially dependent on physical facilities and lack universality and real-time capability.

[0004] (3) Directly read latitude and longitude coordinates: The latitude and longitude values ​​provided by the Global Positioning System (GPS) are lengthy (e.g., 22.543099°N, 114.057868°E), and it is easy to make mistakes when reading them aloud, and it is difficult to remember and record them.

[0005] (4) Shortcomings of existing digital encoding schemes: Schemes such as GeoHash and PlusCodes use mixed alphanumeric encoding (such as Base32 encoding), which is easily confused in voice communication scenarios such as telephone alarms due to similar pronunciations (such as "0" and "O", "1" and "I"). The MGRS military grid reference system has complex rules and requires special training. what3words uses word encoding, which has problems with multilingual support and homonym confusion. Some pure digital geolocation encoding schemes (such as Chinese patents CN117556845A and CN120492703A) are either limited to specific geographical areas or use multi-layer recursive nested structures, failing to achieve efficient encoding and decoding of fixed-length pure digital short codes globally, and lacking a context-based fast filtering mechanism for alarm scenarios.

[0006] Therefore, there is an urgent need for a pure digital location coding scheme that can overcome letter confusion, achieve global coverage, is computationally simple, is particularly optimized for voice transmission, and can quickly decode using contextual information such as the city name most easily provided by the alarm caller. Summary of the Invention

[0007] To address the shortcomings of the prior art, the present invention provides an encoding / decoding method, apparatus, and system for emergency alarms.

[0008] The technical problem to be solved by the present invention is achieved through the following technical solution: A coding method for emergency alarms includes the following steps: Step S1: Obtain the latitude and longitude coordinates of the target location; Step S2: Encode the latitude and longitude coordinates according to the preset encoding and decoding parameters to convert the latitude and longitude coordinates into pure digital short codes and then output them; The encoding / decoding parameters include the maximum positioning error of the global geographic grid and the target character length of the pure digital short code. In step S2, the encoding process for the latitude and longitude coordinates is as follows: Step S21: Based on the maximum positioning error, determine the latitude grid index value of the target grid cell to which the latitude and longitude coordinates belong in the latitude direction and the longitude grid index value in the longitude direction, as well as the total number of grid cells of the global geographic grid in the longitude direction; Step S22: Based on the total number of grid cells, perform a dimensionality reduction mapping operation on the two-dimensional grid index containing the latitude index value and the longitude index value to convert the two-dimensional grid index into a one-dimensional linear index value. The one-dimensional linear index value is used to uniquely represent the sequential position of the target grid cell in the global geographic grid. Step S23: Based on the target character length, perform modulo operation and character formatting on the one-dimensional linear index value to obtain a pure numeric short code with the target character length.

[0009] Furthermore, the maximum positioning error includes the maximum latitudinal positioning error value in the latitudinal direction. And the maximum longitude positioning error value in the longitude direction. In step S21, the latitude grid index value i and the longitude grid index value j are as follows: Wherein, lat is the latitude coordinate of the target location, lng is the longitude coordinate of the target location, and lat_min and lng_min are the starting latitude and longitude for positioning, respectively. *) is the floor function; Total number of grid cells in the longitude direction of the global geographic grid As shown below, In step S22, the one-dimensional linear index value IDX is shown below. In step S23, the pure digital short code c is as follows: Where N is the length of the target character, and mod(*) is the modulo function, indicating the modulus used. For the one-dimensional linear index value Perform modulo operation; This is a character formatting function that indicates that zeros are padded when the modulo value output by the modulo operation does not reach the target character length N.

[0010] Furthermore, the target character length N ranges from 6 to 8, and the maximum latitude positioning error value... and the maximum positioning error value of longitude The value ranges from 0.0005° to 0.001°.

[0011] A decoding method for emergency alarms, used to restore the latitude and longitude coordinates of the target location from a pure digital short code generated using the above encoding method; the decoding method includes the following steps: Step D1: Receive the pure digital short code and the context location description information associated with the alarm event, wherein the context location description information includes at least the city name provided by the alarm user or determined by the system; Step D2: Decode the pure digital short code using the same encoding and decoding parameters as during encoding, so as to restore the pure digital short code to the latitude and longitude coordinates of multiple candidate locations, thereby forming a candidate point list containing at least one candidate location. Step D3: Output the candidate point list for the emergency responders or rescue system to confirm the final location; In step D2, the decoding process for the pure digital short code is as follows: Step D21: Based on the target character length, perform a modular inverse operation on the pure numeric short code to obtain multiple linear index candidate values ​​with the same remainder; Step D22: Based on the total number of grid cells, perform a dimension-up mapping operation on each linear index candidate value to restore each linear index candidate value to the latitude candidate index value and the longitude candidate index value of the candidate grid cell to which it belongs. Step D23: Based on the maximum positioning error, determine the latitude and longitude coordinates of the corresponding candidate location for each candidate grid cell, considering the latitude and longitude candidate index values.

[0012] Furthermore, in step D2, the step of decoding the pure digital short code also includes the following steps: Step D24: Obtain the city boundary coordinate data corresponding to the city name, and filter the candidate locations in the candidate point list according to the city boundary coordinate data, remove candidate locations whose latitude and longitude coordinates are outside the city boundary coordinate data, and retain candidate locations whose latitude and longitude coordinates are within the city boundary coordinate data.

[0013] Furthermore, the maximum positioning error includes the maximum latitudinal positioning error value in the latitudinal direction. And the maximum longitude positioning error value in the longitude direction. In step D21, the k-th linear index candidate value L k As shown below, Where c is the pure numeric short code, and N is the target character length. The modulus k used for the modular inverse operation of the pure digital short code c, the range of values ​​of k satisfies , ; In step D22, the latitude candidate index value of the candidate grid cell to which the k-th linear index candidate value belongs. and longitude candidate index values As shown below, in, The total number of grid cells, The function is called floor function; mod(*) is the modulo function, indicating the use of the modulus. For the k-th linear index candidate value L k Perform modulo operation; In step D23, the latitude and longitude coordinates of the k-th candidate location are as follows: Wherein, lat_min and lng_min are the starting latitude and starting longitude for positioning, respectively.

[0014] Furthermore, the target character length N ranges from 6 to 8, and the maximum latitude positioning error value... and the maximum positioning error value of longitude The value ranges from 0.0005° to 0.001°.

[0015] Furthermore, in step D3, the city boundary coordinate data uses polygonal data of the city's administrative division, or circular area data of the city's center point coordinates within a preset coverage radius; when the preset coverage radius is used, the preset coverage radius is preset according to the city's administrative level or population size, and the value ranges from 30 kilometers to 100 kilometers; when the city boundary coordinate data of the city name cannot be obtained, the city's center point coordinates are used by default, and the city boundary coordinate data is determined by combining the preset coverage radius.

[0016] An encoding / decoding device for emergency alarms includes a processor and a memory connected together. The memory stores a computer program that the processor can execute. When the processor executes the computer program, it performs the above-described encoding method or the above-described decoding method.

[0017] An encoding and decoding system for emergency alarms includes an encoding device, a decoding device, and a display carrier. The encoding device is used to employ the above encoding method to convert the latitude and longitude coordinates of the target location into the pure digital short code; The display carrier is used to display the pure digital short code; The decoding device is used to interface with the alarm receiving system and the urban spatial database to receive the pure digital short code and the contextual location description information associated with the alarm event from the alarm receiving system, obtain the city boundary coordinate data corresponding to the city name from the urban spatial database, and use the above-mentioned decoding method to restore the pure digital short code into a candidate point list containing at least one candidate location, for alarm personnel or rescue system to confirm the final location.

[0018] Furthermore, the encoding and decoding system also includes a display carrier for displaying the pure digital short code.

[0019] The present invention has the following beneficial effects: The present invention divides the geographic grid into uniform grid units based on the global latitude and longitude coordinate system and a fixed maximum positioning error, and uses a dimension reduction mapping operation to convert the two-dimensional grid index into the one-dimensional linear index value. Then, through modulo operation and character formatting, a pure numeric short code with the target character length is generated, which completely avoids the confusion between letters and numbers in speech and realizes a pure digital speech-friendly encoding that is "what you see is what you read, and what you read is what you get". During decoding, the inverse modulo operation is used to generate congruent linear index candidate values, which are restored to candidate grid indexes through a dimension increase mapping operation. Then, based on the maximum positioning error, the latitude and longitude coordinates of multiple candidate locations worldwide are determined to achieve global positioning. This invention further combines the city name most easily provided by the alarm user with the city boundary coordinate data in the city spatial database for efficient filtering, which can instantly reduce thousands of candidate locations worldwide to 1-3. It has low computational complexity, global coverage, compatibility with existing alarm processes, and is easy to promote and integrate on various devices and public facilities. Attached Figure Description

[0020] Figure 1 A flowchart illustrating the steps of the encoding method provided by this invention.

[0021] Figure 2 This is a step-by-step flowchart of step S2 in the encoding method provided by the present invention.

[0022] Figure 3 A flowchart illustrating the steps of the decoding method provided by this invention.

[0023] Figure 4 This is a step-by-step flowchart of step D2 in the decoding method provided by the present invention.

[0024] Figure 5 This is a step-by-step flowchart of step D2 in another decoding method provided by the present invention.

[0025] Figure 6 This is a structural block diagram of the encoding and decoding system provided by the present invention. Detailed Implementation

[0026] The present invention will now be described in detail with reference to the accompanying drawings and embodiments, examples of which are shown in the drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and intended to explain the present invention, and should not be construed as limiting the present invention.

[0027] In the description of this invention, it should be understood that the terms "length", "width", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention.

[0028] Furthermore, the terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first," "second," or "third" may explicitly or implicitly include one or more of that feature. In the description of this invention, "multiple" means two or more, unless otherwise explicitly specified.

[0029] In this invention, unless otherwise explicitly specified and limited, the terms "installation," "connection," "linking," "fixing," and "setting," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0030] Example 1 like Figure 1 and 2 As shown, a coding method for emergency alarms includes the following steps: Step S1: Obtain the latitude and longitude coordinates of the target location.

[0031] In step S1, the latitude and longitude coordinates of the target location can be manually input into the encoding device, or a GPS positioning system can be integrated into the encoding device so that the encoding device can automatically obtain the latitude and longitude coordinates of the target location.

[0032] Step S2: Encode the latitude and longitude coordinates according to the preset encoding and decoding parameters to convert the latitude and longitude coordinates into pure digital short codes and then output them.

[0033] Specifically, the encoding and decoding parameters include the maximum positioning error of the global geographic grid and the target character length of the pure digital short code. In step S2, the steps for encoding the latitude and longitude coordinates are as follows: Step S21: Based on the maximum positioning error, determine the latitude grid index value of the target grid cell to which the latitude and longitude coordinates belong in the latitude direction and the longitude grid index value in the longitude direction, as well as the total number of grid cells of the global geographic grid in the longitude direction.

[0034] In step S21, the maximum positioning error includes the maximum positioning error value in the latitude direction. And the maximum longitude positioning error value in the longitude direction. .

[0035] The maximum positioning error value of latitude and the maximum positioning error value of longitude The smaller the value, the greater the accuracy of reconstructing the latitude and longitude coordinates of the target location during the subsequent decoding process. However, the decoding and reconstruction process also requires more computation time. Therefore, the maximum latitude positioning error value... and the maximum positioning error value of longitude Smaller is not necessarily better; both restoration accuracy and restoration speed need to be considered.

[0036] Currently, the accuracy of open services for civilian GPS is typically within the range of 4-10 meters, therefore the maximum latitude positioning error value mentioned above... and the maximum positioning error value of longitude It needs to be at least greater than the accuracy range of civilian GPS.

[0037] GPS latitude and longitude output is based on the WGS-84 ellipsoid, with a latitude domain of [-90°, 90°] and an accuracy domain of [-180°, 180°]. Due to the different domain ranges, the maximum positioning error value of the latitude is [not specified]. and the maximum positioning error value of longitude They can be the same or different.

[0038] In this embodiment, the maximum latitude positioning error value and the maximum positioning error value of longitude Both are 0.0005°. The physical distance corresponding to 0.0005° latitude is approximately 55.66 meters, and the physical distance of 0.0005° longitude at the equator is also approximately 55.66 meters.

[0039] The latitude grid index value i and the longitude grid index value j are shown below. Total number of grid cells in the longitude direction of the global geographic grid As shown below, Wherein, lat is the latitude coordinate of the target location, lng is the longitude coordinate of the target location, and lat_min and lng_min are the starting latitude and longitude for positioning, respectively. *) is the floor function.

[0040] In this embodiment, the starting latitude for positioning, lat_min, is -90°, and the starting longitude for positioning, lng_min, is -180°.

[0041] In map projection, the southwest corner (-90°, -180°) is often used as the starting point of the global grid, with the index increasing eastward and northward. This is similar to the "top left corner as the origin" convention in computer image processing, and is an intuitive agreement. Meanwhile, the latitude and longitude output by GPS are based on the WGS-84 ellipsoid, whose domain is [-90°, 90°] and [-180°, 180°]. Therefore, the starting latitude for positioning, lat_min = -90°, and the starting longitude for positioning, lng_min = -180°, are based on the usage specifications of maps and the Global Positioning System.

[0042] In fact, the starting latitude and starting longitude of the positioning can be any values, as long as global indexing can be completed.

[0043] Step S22: Based on the total number of grid cells, perform a dimensionality reduction mapping operation on the two-dimensional grid index containing the latitude index value and the longitude index value to transform the two-dimensional grid index into a one-dimensional linear index value. The one-dimensional linear index value is used to uniquely represent the sequential position of the target grid cell in the global geographic grid.

[0044] In step 22, the one-dimensional linear index value IDX is shown below. Where i is the latitude grid index value, and j is the longitude grid index value. This represents the total number of grid cells in the longitude direction of the global geographic grid.

[0045] Step S23: Based on the target character length, perform modulo operation and character formatting on the one-dimensional linear index value to obtain a pure numeric short code with the target character length.

[0046] In step S23, the pure digital short code c is as follows: Where IDX is the one-dimensional linear index value, N is the target character length, and mod(*) is the modulo function, indicating the modulus used. For the one-dimensional linear index value Perform modulo operation; This is a character formatting function that indicates that zeros are padded when the modulo value output by the modulo operation does not reach the target character length N.

[0047] The larger the target character length N is, the less convenient it is for the alarm person to read and remember. Conversely, the smaller the target character length N is, the more candidate locations will be output during the subsequent decoding and reconstruction process, resulting in lower positioning accuracy. Furthermore, there may be cases where multiple candidate locations remain even when combined with the city boundary coordinate data of the city.

[0048] The latitude and longitude span of most major cities worldwide is ≤2°, and that of some megacities is ≤3°. To meet the positioning accuracy requirements within a single city, the target character length N ranges from 6 to 8, and the maximum positioning error value for latitude is... and the maximum positioning error value of longitude The value ranges from 0.0005° to 0.001°. Preferably, the maximum latitude positioning error value is... and the maximum positioning error value of longitude same.

[0049] In this embodiment, the target character length N is 8, and the maximum latitude positioning error value is... and the maximum positioning error value of longitude All values ​​are 0.0005°.

[0050] Example 2 like Figure 3 and 4 As shown, a decoding method for emergency alarms is used to restore the latitude and longitude coordinates of the target location from a pure digital short code generated using the encoding method described in Embodiment 1; the decoding method includes the following steps: Step D1: Receive the pure digital short code and the context location description information associated with the alarm event, wherein the context location description information includes at least the city name provided by the alarm user or determined by the system.

[0051] In step D1, the pure digital short code and context location description information can be obtained by the encoding device through interfacing with the alarm receiving system.

[0052] The contextual location description information refers to the description information about the location provided by the alarm caller when making the alarm, as recorded by the alarm receiving system or the alarm receiving personnel. For example, the city name of the location directly provided by the alarm caller, or the city name determined by the alarm receiving system or the alarm receiving personnel based on the description information about the location provided by the alarm caller.

[0053] Step D2: Decode the pure digital short code using the same encoding and decoding parameters as during encoding, so as to restore the pure digital short code to the latitude and longitude coordinates of multiple candidate locations, thereby forming a candidate point list containing at least one candidate location.

[0054] Specifically, the encoding and decoding parameters include the maximum positioning error of the global geographic grid and the target character length of the pure numeric short code. In step D2, the decoding process for the pure numeric short code is as follows: Step D21: Based on the target character length, perform a modulo inverse operation on the pure numeric short code to obtain multiple linear index candidate values ​​with the same remainder.

[0055] In step D21, the maximum positioning error includes the maximum positioning error value in the latitude direction. And the maximum longitude positioning error value in the longitude direction. The k-th linear index candidate value L k As shown below, Where c is the pure numeric short code, and N is the target character length. The modulus k used for the modular inverse operation of the pure digital short code c, the range of values ​​of k satisfies , .

[0056] Step D22: Based on the total number of grid cells, perform a dimension-up mapping operation on each linear index candidate value to restore each linear index candidate value to the latitude candidate index value and the longitude candidate index value of the candidate grid cell to which it belongs.

[0057] In step D22, the latitude candidate index value of the candidate grid cell to which the k-th linear index candidate value belongs. and longitude candidate index values As shown below, in, The total number of grid cells, The function is called floor function; mod(*) is the modulo function, indicating the use of the modulus. For the k-th linear index candidate value L k Perform modulo operation; Step D23: Based on the maximum positioning error, determine the latitude and longitude coordinates of the corresponding candidate location for each candidate grid cell, considering the latitude and longitude candidate index values.

[0058] In step D23, the latitude and longitude coordinates of the k-th candidate location are as follows: Wherein, lat_min and lng_min are the starting latitude and starting longitude for positioning, respectively.

[0059] The latitude and longitude span of most major cities worldwide is ≤2°, and that of some megacities is ≤3°. To meet the positioning accuracy requirements within a single city, the target character length N ranges from 6 to 8, and the maximum positioning error value for latitude is... and the maximum positioning error value of longitude The value ranges from 0.0005° to 0.001°. Preferably, the maximum latitude positioning error value is... and the maximum positioning error value of longitude same.

[0060] In this embodiment, the target character length N is 8, and the maximum latitude positioning error value is... and the maximum positioning error value of longitude Both are set to 0.0005°, the starting latitude for positioning is lat_min -90°, and the starting longitude for positioning is lng_min -180°.

[0061] Step D4: Output the candidate point list for the emergency responders or rescue system to confirm the final location.

[0062] In step D4, if there is only one candidate location in the candidate point list, the dispatcher or rescue system can confirm that candidate location as the final location of the target location. If there are two or more candidate locations in the candidate point list, the dispatcher or rescue system can provide verbal guidance to the caller to obtain more information about the caller's location, thereby further filtering the candidate locations.

[0063] Based on the periodicity of the modulo operation, the number of candidate locations obtained after decoding each pure digital short code is shown below. The latitude difference between two adjacent candidate locations is as follows: The longitude difference between two adjacent candidate locations is as follows: Assuming the target character length N=8, the maximum latitude positioning error value... =Maximum positioning error value based on longitude =0.0005°, then the number of candidate locations after decoding each pure digital short code is Q=2592, and the latitude difference between two adjacent candidate locations is... Longitude difference between two adjacent candidate locations Although the latitude difference between two adjacent candidate locations is not large, the longitude difference reaches 40°. Most cities in the world do not have a longitude span of 40°. Therefore, as long as the person reporting the incident can accurately state the name of the city, or the alarm receiving system can determine the name of the city based on the location description of the person reporting the incident, global positioning can be achieved.

[0064] As described above, the latitudinal length distance obtained by the decoding method of this invention is globally uniform, but the longitudinal length distance varies depending on the latitude. Taking China as an example, the highest latitude in China (Mohe) is approximately 53.5°N, and the lowest latitude (Zengmu Reef) is approximately 3.5°N. Two adjacent candidate locations are located at the highest latitude... When global positioning is not required, and positioning within a single city is only needed, the preferred method is, for example... Figure 5 As shown, in step D2, the step of decoding the pure digital short code further includes the following steps: Step D24: Obtain the city boundary coordinate data corresponding to the city name, and filter the candidate locations in the candidate point list according to the city boundary coordinate data. Eliminate candidate locations whose latitude and longitude coordinates are outside the city boundary coordinate data, and retain candidate locations whose latitude and longitude coordinates are within the city boundary coordinate data to obtain the filtered candidate point list.

[0065] In step D3, the city boundary coordinate data can be obtained by the encoding device by interfacing with the city spatial database.

[0066] The city boundary coordinate data uses polygonal data of the city's administrative divisions, or circular area data of the city's center point coordinates within a preset coverage radius. When the preset coverage radius is used, it is preset according to the city's administrative level or population size, and its value ranges from 30 kilometers to 100 kilometers. When the city boundary coordinate data of the city name cannot be obtained, the city's center point coordinates are used by default, and the city boundary coordinate data is determined by combining the preset coverage radius.

[0067] Actual verification shows that even in high-latitude regions (where the length and distance within the same latitude difference are smaller), the decoding method of this invention ultimately outputs a list of at most 3 candidate locations after filtering, and the physical distance between each candidate location reaches more than 20 kilometers. Therefore, as long as the person reporting the incident can further state the name of the county, street, or location characteristics, the dispatcher or rescue system can confirm the final location.

[0068] Example 3 An encoding / decoding device for emergency alarms includes a processor and a memory connected together. The memory stores a computer program that the processor can execute. When the processor executes the computer program, it performs the encoding method described in Embodiment 1 or the decoding method described in Embodiment 2.

[0069] Example 4 like Figure 6 As shown, an encoding and decoding system for emergency alarms includes an encoding device, a decoding device, and a display device. The encoding device is used to employ the encoding method described in Embodiment 1 to convert the latitude and longitude coordinates of the target location into the pure digital short code; The display carrier is used to display the pure digital short code; The decoding device is used to interface with the alarm receiving system and the urban spatial database to receive the pure digital short code and the context location description information associated with the alarm event from the alarm receiving system, obtain the city boundary coordinate data corresponding to the city name from the urban spatial database, and use the decoding method described in Embodiment 2 to restore the pure digital short code into a candidate point list containing at least one candidate location, for alarm personnel or rescue system to confirm the final location.

[0070] The display carrier may include, but is not limited to, immovable physical carriers such as streetlights, curbs / roadsides, ground markings, bus stop signs, and building exteriors, as well as software programs such as mobile map apps and mini-programs installed in the encoding device, and mobile terminals with GPS functionality.

[0071] For immovable physical carriers, the latitude and longitude coordinates of each physical carrier's location can be pre-encoded into a corresponding pure digital short code using the decoding device. This pure digital short code is then printed on the corresponding physical carrier, allowing the alarm user to quickly obtain the pure digital short code of the target location from a nearby physical carrier. For mobile map apps, mobile mini-programs, and mobile terminals with GPS functionality, the decoding device is integrated within them. It can automatically obtain the latitude and longitude coordinates of the alarm user's target location, encode these coordinates into a corresponding pure digital short code, and display the pure digital short code on the screen.

[0072] In this embodiment, the target character length N is 8, and the maximum latitude positioning error value is... and the maximum positioning error value of longitude The coordinates are the same and both are 0.0005°, the starting latitude of the positioning lat_min is -90°, and the starting longitude of the positioning lng_min is -180°.

[0073] Taking Shenzhen as an example, an average of 10 target locations are selected within Shenzhen. The latitude and longitude coordinates of these 10 locations are then encoded to obtain corresponding short numeric codes. These 10 short numeric codes are then decoded and filtered using city boundary data to obtain a candidate point list for each short numeric code. The details are shown in the table below. Serial Number Location Description Latitude (°N) Longitude (°E) Short code (8 digits) Decoded and filtered latitude (°N) Decoded and filtered longitude (°E) The corresponding k value 1 Civic Center (Center) 22.543099 114.057868 62508115 22.543 114.0575 1620 2 Dapeng Peninsula (eastern end) 22.590000 114.500000 30189000 22.590 114.500 1621 3 Guangming District (Northwest) 22.750000 113.920000 60587840 22.750 113.920 1623 4 Futian Port (South End) 22.503000 114.065000 04908130 22.503 114.065 1620 5 Songgang (west end) 22.780000 113.820000 03787640 22.780 113.820 1624 6 Pingshan (Northeast) 22.720000 114.350000 17388700 22.720 114.350 1623 7 Shekou (Southwest) 22.480000 113.910000 71787820 22.480 113.910 1619 8 Salt fields (southeast) 22.560000 114.250000 86988500 22.560 114.250 1620 9 Longhua (north-central part) 22.650000 114.030000 16588060 22.650 114.030 1622 10 Bao'an Airport (West) 22.639000 113.811000 00747622 22.639 113.811 1622 The table above selects 10 representative locations in Shenzhen (including the city center, administrative district endpoints, transportation hubs, and functional areas) for encoding and decoding verification. The latitude and longitude coordinates of all locations were converted into 8-bit pure numeric short codes using the method of this invention, and then decoded and spatially filtered in conjunction with the city name context. Results show that all locations can achieve accurate bidirectional mapping between the short code and latitude and longitude; the decoded latitude and longitude coordinates are highly consistent with the original coordinates, and the positioning error is controlled within the grid accuracy range. After filtering by city boundary data, all global candidate locations corresponding to the short codes quickly converge to a single valid point, with no redundant candidate outputs. Experimental data fully verify the accuracy, stability, and practicality of the encoding and decoding method of this invention, and can meet the needs of fast, accurate, and voice-friendly location transmission and positioning in emergency alarm scenarios.

[0074] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the embodiments of the present invention and not to limit them. Although the embodiments of the present invention have been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can still be made to the technical solutions of the embodiments of the present invention, and these modifications or equivalent substitutions cannot cause the modified technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A coding method for emergency alarms, characterized in that, Includes the following steps: Step S1: Obtain the latitude and longitude coordinates of the target location; Step S2: Encode the latitude and longitude coordinates according to the preset encoding and decoding parameters to convert the latitude and longitude coordinates into pure digital short codes and then output them; The encoding / decoding parameters include the maximum positioning error of the global geographic grid and the target character length of the pure digital short code. In step S2, the encoding process for the latitude and longitude coordinates is as follows: Step S21: Based on the maximum positioning error, determine the latitude grid index value of the target grid cell to which the latitude and longitude coordinates belong in the latitude direction and the longitude grid index value in the longitude direction, as well as the total number of grid cells of the global geographic grid in the longitude direction; Step S22: Based on the total number of grid cells, perform a dimensionality reduction mapping operation on the two-dimensional grid index containing the latitude index value and the longitude index value to convert the two-dimensional grid index into a one-dimensional linear index value. The one-dimensional linear index value is used to uniquely represent the sequential position of the target grid cell in the global geographic grid. Step S23: Based on the target character length, perform modulo operation and character formatting on the one-dimensional linear index value to obtain a pure numeric short code with the target character length.

2. The encoding method according to claim 1, characterized in that, The maximum positioning error includes the maximum positioning error value in the latitude direction. And the maximum longitude positioning error value in the longitude direction. In step S21, the latitude grid index value i and the longitude grid index value j are as follows: Wherein, lat is the latitude coordinate of the target location, lng is the longitude coordinate of the target location, and lat_min and lng_min are the starting latitude and longitude for positioning, respectively. *) is the floor function; Total number of grid cells in the longitude direction of the global geographic grid As shown below, In step S22, the one-dimensional linear index value IDX is shown below. In step S23, the pure digital short code c is as follows: Where N is the length of the target character, and mod(*) is the modulo function, indicating the modulus used. For the one-dimensional linear index value Perform modulo operation; This is a character formatting function that indicates that zeros are padded when the modulo value output by the modulo operation does not reach the target character length N.

3. The encoding method according to claim 2, characterized in that, The target character length N ranges from 6 to 8, and the maximum latitude positioning error value... and the maximum positioning error value of longitude The value ranges from 0.0005° to 0.001°.

4. A decoding method for emergency alarms, characterized in that, The decoding method is used to restore the pure digital short code generated by the encoding method described in claim 1 to the latitude and longitude coordinates of the target location; the decoding method includes the following steps: Step D1: Receive the pure digital short code and the context location description information associated with the alarm event, wherein the context location description information includes at least the city name provided by the alarm user or determined by the system; Step D2: Decode the pure digital short code using the same encoding and decoding parameters as during encoding, so as to restore the pure digital short code to the latitude and longitude coordinates of multiple candidate locations, thereby forming a candidate point list containing at least one candidate location. Step D3: Output the candidate point list for the emergency responders or rescue system to confirm the final location; In step D2, the decoding process for the pure digital short code is as follows: Step D21: Based on the target character length, perform a modular inverse operation on the pure numeric short code to obtain multiple linear index candidate values ​​with the same remainder; Step D22: Based on the total number of grid cells, perform a dimension-up mapping operation on each linear index candidate value to restore each linear index candidate value to the latitude candidate index value and the longitude candidate index value of the candidate grid cell to which it belongs. Step D23: Based on the maximum positioning error, determine the latitude and longitude coordinates of the corresponding candidate location for each candidate grid cell, considering the latitude and longitude candidate index values.

5. The decoding method according to claim 4, characterized in that, In step D2, the decoding process for the pure digital short code further includes the following steps: Step D24: Obtain the city boundary coordinate data corresponding to the city name, and filter the candidate locations in the candidate point list according to the city boundary coordinate data, remove candidate locations whose latitude and longitude coordinates are outside the city boundary coordinate data, and retain candidate locations whose latitude and longitude coordinates are within the city boundary coordinate data.

6. The decoding method according to claim 4, characterized in that, The maximum positioning error includes the maximum positioning error value in the latitude direction. And the maximum longitude positioning error value in the longitude direction. In step D21, the k-th linear index candidate value L k As shown below, Where c is the pure numeric short code, and N is the target character length. The modulus k used for the modular inverse operation of the pure digital short code c, the range of values ​​of k satisfies , ; In step D22, the latitude candidate index value of the candidate grid cell to which the k-th linear index candidate value belongs. and longitude candidate index values As shown below, in, The total number of grid cells, The function is called floor function; mod(*) is the modulo function, indicating the use of the modulus. For the k-th linear index candidate value L k Perform modulo operation; In step D23, the latitude and longitude coordinates of the k-th candidate location are as follows: Wherein, lat_min and lng_min are the starting latitude and starting longitude for positioning, respectively.

7. The decoding method according to claim 4, characterized in that, The target character length N ranges from 6 to 8, and the maximum latitude positioning error value... and the maximum positioning error value of longitude The value ranges from 0.0005° to 0.001°.

8. The decoding method according to claim 4, characterized in that, In step D3, the city boundary coordinate data uses polygonal data of the city's administrative divisions, or circular area data of the city's center point coordinates within a preset coverage radius. When the preset coverage radius is used, it is preset according to the city's administrative level or population size, and its value ranges from 30 kilometers to 100 kilometers. When the city boundary coordinate data of the city name cannot be obtained, the city's center point coordinates are used by default, and the city boundary coordinate data is determined by combining the preset coverage radius.

9. A codec device for emergency alarms, comprising a processor and a memory connected together, wherein the memory stores a computer program for execution by the processor, characterized in that, When the processor executes the computer program, it performs the encoding method of claim 1 or the decoding method of claim 4.

10. A codec system for emergency alarms, characterized in that, Includes encoding device, decoding device and display medium, The encoding device is used to employ the encoding method described in claim 1 to convert the latitude and longitude coordinates of the target location into the pure digital short code; The display carrier is used to display the pure digital short code; The decoding device is used to interface with the alarm receiving system and the urban spatial database to receive the pure digital short code and the context location description information associated with the alarm event from the alarm receiving system, obtain the city boundary coordinate data corresponding to the city name from the urban spatial database, and use the decoding method of claim 4 to restore the pure digital short code into a candidate point list containing at least one candidate location for alarm personnel or rescue system to make final location confirmation.

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