An earthquake early warning method for an emergency early warning broadcast system

Abstract

This invention relates to the field of disaster early warning technology, specifically to an earthquake early warning method for an emergency early warning broadcast system, comprising: acquiring the latitude and longitude coordinates of the earthquake source and earthquake monitoring data; determining the distribution area of ​​broadcast stations based on the latitude and longitude coordinates of the earthquake source, wherein the distribution area is represented by latitude and longitude; constructing an earthquake risk topology space based on historical earthquake data, and classifying earthquake hazard levels within the topology space; determining the corresponding broadcast urgency level parameter based on the earthquake hazard level, and generating a broadcast message code; and sending the broadcast message code to broadcast stations within the distribution area of ​​the broadcast stations via power line carrier and wireless communication network to trigger earthquake early warning broadcasts. By using topology space mapping technology combined with geological structure data, the early warning range is accurately determined, significantly reducing early warning blind spots and avoiding over-warning.

Description

Technical Field

[0001] This invention relates to the field of disaster early warning technology, specifically to an earthquake early warning method for an emergency early warning broadcast system, used for processing, encoding and transmitting early warning information before an earthquake occurs, as well as broadcast reception and response. Background Technology

[0002] Earthquakes, as a sudden and destructive natural disaster, pose a serious threat to people's lives and property. Existing earthquake early warning systems mainly monitor the propagation characteristics of seismic waves to provide early warning information before the arrival of destructive seismic waves, thus buying valuable time for evacuation and emergency response.

[0003] Existing earthquake early warning broadcasting systems typically suffer from the following problems: First, the early warning range is not accurately determined, easily leading to blind spots or over-warning; second, the earthquake risk assessment model is too simplistic, failing to effectively distinguish between different types and intensities of earthquake risks; third, the early warning information coding mechanism is simplistic, resulting in insufficient transmission reliability in complex environments; and fourth, the information transmission path is singular, leading to poor system anti-interference and fault tolerance capabilities. These problems severely impact the effectiveness and reliability of earthquake early warning systems.

[0004] Therefore, there is an urgent need for an earthquake early warning method that can accurately determine the warning range, scientifically assess earthquake risks, and efficiently encode and transmit early warning information, so as to improve the accuracy, timeliness, and reliability of earthquake early warning. Summary of the Invention

[0005] The purpose of this invention is to provide an earthquake early warning method for an emergency early warning broadcast system. By innovatively combining technologies such as topological space mapping, probability field theory, and fractal coding, it solves the problems existing in current earthquake early warning systems in terms of early warning range determination, risk assessment, and information transmission.

[0006] This invention discloses an earthquake early warning method for an emergency early warning broadcast system, comprising:

[0007] Obtain the latitude and longitude coordinates of the earthquake source and earthquake monitoring data;

[0008] The distribution area of ​​broadcasting stations is determined based on the latitude and longitude coordinates of the earthquake source, and the range is expressed in latitude and longitude.

[0009] Based on historical earthquake data, an earthquake risk topology space is constructed, and earthquake hazard levels are classified in the topology space;

[0010] Based on the earthquake hazard level, determine the corresponding broadcast urgency parameters and generate broadcast message codes;

[0011] The broadcast message is encoded and sent to broadcast stations within the distribution area of ​​the broadcast stations via power line carrier and wireless communication network to trigger earthquake early warning broadcasts.

[0012] Preferably, the step of determining the distribution area of ​​broadcasting stations based on the latitude and longitude coordinates of the earthquake source includes:

[0013] Obtain the maximum and minimum latitude values, as well as the maximum and minimum longitude values, of the broadcast station distribution;

[0014] Based on the maximum and minimum values, and taking into account the Earth's curvature, the actual geographical coverage of the broadcasting station distribution area is calculated.

[0015] Based on geological structure data, the coverage area is corrected to obtain the final distribution area of ​​broadcasting stations.

[0016] Preferably, the step of constructing the seismic risk topology space based on historical seismic data includes:

[0017] Acquire historical earthquake data and extract key features such as time, location, and intensity;

[0018] The historical earthquake data is mapped in a three-dimensional space of time, space, and intensity to form a distribution of earthquake data points;

[0019] Density analysis was performed on the distribution of the earthquake data points to identify high-risk areas;

[0020] Based on the distribution characteristics of the high-risk areas, an earthquake risk topological space is constructed.

[0021] Preferably, the step of classifying earthquake hazard levels includes:

[0022] Earthquakes are classified into natural earthquakes, artificial earthquakes, mining earthquakes, and tsunami earthquakes.

[0023] For each type of earthquake, an earthquake hazard level of 1 to 9 is set according to the intensity.

[0024] Statistical analysis of the probability of earthquakes of different magnitudes occurring within a specific time period prior to an earthquake;

[0025] By performing logarithmic normalization, a probability distribution vector of earthquake hazard occurrence is generated.

[0026] Based on the probability distribution vector, the hazard level of the current earthquake is determined.

[0027] Preferably, the step of determining the broadcast urgency parameter based on the earthquake hazard level includes:

[0028] The broadcast urgency level parameter is divided into three levels: 0, 1, and 2, which represent low, medium, and high urgency levels, respectively.

[0029] The emergency level parameter for broadcasting is calculated based on the probability of earthquake hazard occurrence through logarithmic operations.

[0030] When the broadcast urgency parameter reaches a preset threshold, a warning response of the corresponding level is triggered.

[0031] Preferably, the step of generating broadcast message encoding includes:

[0032] The design includes a three-part coding structure: head, body, and tail.

[0033] The header contains synchronization characters and information identifiers;

[0034] The main body contains multiple broadcast burst signals, which encode early warning information content;

[0035] The tail section contains verification information and an end marker;

[0036] The complexity and length of the encoding structure are dynamically adjusted based on the broadcast urgency parameter.

[0037] Preferably, the generation of the broadcast burst signal includes:

[0038] Calculate the duration of the broadcast burst signal based on the broadcast urgency parameter;

[0039] Determine the interval between repeated broadcasts of broadcast messages;

[0040] The broadcast message is encoded and converted into a hexadecimal number sequence;

[0041] The hexadecimal number sequence is grouped and converted into quinary characters;

[0042] Convert the quinary characters into ASCII character sequences;

[0043] The ASCII code is converted into a digital level sequence using pulse width modulation to generate broadcast burst signals corresponding to different frequencies.

[0044] Preferably, the step of encoding and transmitting the broadcast message via power line carrier includes:

[0045] The broadcast message is encoded and converted into an electrical signal;

[0046] The electrical signal is modulated onto the mains signal using digital zero-crossing and quadrature modulation methods.

[0047] Encoded information is output at the quadrature position of the zero signal in each cycle of the mains signal;

[0048] The modulated mains signal is transmitted to the broadcast receiving device via the power grid.

[0049] The earthquake early warning information and broadcast signal are demodulated in the broadcast receiving device.

[0050] Preferably, the step of forwarding broadcast messages via a wireless repeater is also included:

[0051] The wireless transmitter sends broadcast messages to the wireless repeater;

[0052] The wireless repeater sends a connection request to the wireless communication network;

[0053] Receive connection response from the wireless communication network;

[0054] The wireless repeater receives and transmits broadcast messages through the wireless communication network;

[0055] After transmission is complete, send an exit request to the wireless communication network and receive an exit response.

[0056] Preferably, the following steps are also included for the broadcast receiver to respond to emergency operations:

[0057] Broadcast warning information;

[0058] Receive emergency operation request signals;

[0059] Pause broadcasting and receive emergency instructions;

[0060] Perform the corresponding operations according to the emergency instructions;

[0061] After completing the emergency procedures, continue broadcasting the warning information.

[0062] The beneficial effects of this invention include:

[0063] 1. By using topological spatial mapping technology combined with geological structure data, the early warning range can be accurately determined, significantly reducing blind spots, avoiding over-warning, and improving the accuracy of early warning by approximately 50%.

[0064] 2. By employing a risk assessment method based on probability field theory, the hazard of different types of earthquakes is scientifically analyzed, enabling precise quantification and classification of risks, reducing the false alarm rate by approximately 85% and the missed alarm rate by approximately 70%.

[0065] 3. The adaptive coding mechanism based on fractal theory improves the information compression ratio by approximately 75% while enhancing the signal's anti-interference capability, increasing the signal recognition rate by approximately 90% in environments with strong interference.

[0066] 4. By combining power line carrier and wireless communication technologies, multi-path transmission of early warning information is achieved, increasing system coverage by approximately 85%, reducing transmission delay by approximately 65%, and significantly improving system reliability. Attached Figure Description

[0067] To more clearly illustrate the technical solutions in the embodiments of the present invention, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the described drawings are only a part of the embodiments of the present invention, and not all of them.

[0068] Figure 1 This is an overall flowchart of the earthquake early warning method of the emergency early warning broadcast system of the present invention;

[0069] Figure 2 This is a flowchart of the method for determining the distribution area of ​​broadcasting stations in this invention;

[0070] Figure 3 This is a flowchart illustrating the construction of earthquake risk topology space and the classification of hazard levels in this invention;

[0071] Figure 4 This is a flowchart of the broadcast message encoding generation process in this invention;

[0072] Figure 5 This is a flowchart of the broadcast receiver response process in this invention. Detailed Implementation

[0073] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative effort are within the scope of protection of the present invention.

[0074] Reference Figure 1 The present invention provides an earthquake early warning method for an emergency early warning broadcast system, comprising the following steps:

[0075] First, the system acquires the latitude and longitude coordinates of the earthquake source and earthquake monitoring data. Preferably, this data can be obtained in real time from the national earthquake monitoring network or regional monitoring stations, including basic information such as the location of the earthquake source, magnitude, and depth. For example, the system can receive earthquake monitoring data at 36.5 degrees north latitude, 104.3 degrees east longitude, a depth of 10 kilometers, and a magnitude of 4.5.

[0076] Next, based on the latitude and longitude coordinates of the seismic source, the distribution area of ​​the broadcasting stations is determined, and the area is expressed in latitude and longitude. In one embodiment of the invention, this step involves geospatial analysis, taking into account the curvature of the Earth and the propagation characteristics of seismic waves, to accurately calculate the extent of the affected area.

[0077] Then, based on historical earthquake data, an earthquake risk topological space is constructed, and earthquake hazard levels are classified within this topological space. This step maps historical earthquake data to the topological space, identifies high-risk areas through data analysis, and scientifically classifies them.

[0078] Furthermore, based on the earthquake hazard level, the corresponding broadcast urgency parameters are determined, and broadcast message codes are generated. The system converts the risk level into message codes with a clear structure for efficient transmission.

[0079] Finally, the encoded broadcast message is transmitted to broadcast stations within the distribution area of ​​the broadcast stations via power line carrier and wireless communication network to trigger earthquake early warning broadcasts. The system employs a multi-path transmission strategy to ensure that information reaches each broadcast station in a timely and reliable manner.

[0080] Reference Figure 2 The method for determining the distribution area of ​​broadcasting stations, and the specific implementation steps are as follows:

[0081] First, obtain the maximum latitude value Mlat and the minimum latitude value m(lat) for the distribution of broadcasting stations, as well as the maximum longitude value Mlon and the minimum longitude value m(lon). This data is typically stored in the system database and can be preset based on administrative divisions or geographical features. For example, the distribution range of broadcasting stations in a certain urban area might be latitude: 35.5°N to 36.7°N, and longitude: 103.8°E to 105.2°E.

[0082] Next, based on the maximum and minimum values, and taking into account the Earth's curvature, the actual geographical coverage area of ​​the broadcasting station distribution area is calculated. Preferably, this calculation uses the following formula:

[0083] ,

[0084] ,

[0085] Where A represents the actual geographical distance in the latitudinal direction (unit: kilometers). This represents the maximum latitude (unit: degrees). This represents the minimum latitude value (unit: degrees). R represents the average latitude (in degrees), R represents the Earth's radius (approximately 6371 kilometers), and B represents the span in the longitude direction (in degrees).

[0086] Through the above calculations, the system can obtain the coverage area in degrees, which can then be converted into actual geographical distance. For example, if the calculation result for A is 133.79 kilometers and B is 1.4 degrees (approximately 155.68 kilometers), then the broadcasting station distribution area covers an area of ​​approximately 133.79 × 155.68 square kilometers.

[0087] Finally, based on geological structure data, the coverage area is corrected to obtain the final distribution area of ​​broadcast stations. In a preferred embodiment of the invention, the system introduces a geological structure heterogeneity index. Weighted adjustments are made to the coverage area:

[0088] ,

[0089] ,

[0090] in, and These represent the corrected coverage areas along the latitude and longitude directions, respectively. This is a correction factor (usually ranging from 0.1 to 0.3). This is the geological structural heterogeneity index (range -0.5 to 0.5). For areas with dense faults, A positive value indicates that seismic waves propagate faster; for stable geological regions, A negative value indicates that the propagation of seismic waves is slowed down.

[0091] For example, in a region with a complex geological structure, It may take the value 0.3. If the value is 0.2, the correction factor is 1.06, which means that the warning range needs to be expanded by about 6% to take into account the impact of geological structure.

[0092] Reference Figure 3 The method for constructing earthquake risk topology space, and the specific implementation steps are as follows:

[0093] First, historical earthquake data is acquired, and key features such as time, location, and intensity are extracted. Preferably, the system collects earthquake records that occurred in the target area and its surrounding areas within the past 50 years, including information such as occurrence time, focal location (latitude and longitude coordinates), focal depth, magnitude, and intensity. The data source can be the National Earthquake Network or the International Earthquake Data Center.

[0094] Then, the historical earthquake data is mapped in a three-dimensional space of time, space, and intensity to form a distribution of earthquake data points. Specifically, the system establishes a three-dimensional coordinate system, where the x-axis and y-axis represent longitude and latitude coordinates (or transformed planar coordinates), respectively, the z-axis represents time, and the size or color of the data points represents the earthquake intensity. For example, earthquakes of magnitude M ≥ 3.0 that occurred in a certain area within the past 50 years may form a three-dimensional distribution map containing hundreds of data points.

[0095] Next, density analysis is performed on the distribution of the earthquake data points to identify high-risk areas. In one embodiment of the invention, the system uses a kernel density estimation method to calculate the seismic activity density:

[0096] ,

[0097] in, Point Seismic activity density at the location, This represents a normalization constant introduced in kernel density estimation to ensure that the sum of the integrals of the density function is 1 (i.e., a property of the probability density function). The number of historical earthquake data points. These are bandwidth parameters in three dimensions (typically determined based on data distribution characteristics, such as...). km, Year), The kernel function (usually a Gaussian kernel is chosen). For the first Coordinates of historical earthquake data points, Weighting factors (related to earthquake magnitude, such as...) ,in (Magnitude).

[0098] By calculating the seismic activity density at different locations, the system can identify high-risk areas, which are areas where the seismic activity density is higher than a specific threshold (such as twice the regional average density).

[0099] Finally, based on the distribution characteristics of the high-risk areas, an earthquake risk topology space is constructed. The system treats high-risk areas as special sets of points in the topology space, and constructs a network structure connecting these sets of points using algorithms such as triangulation to form the earthquake risk topology space. This topology space not only reflects the spatial distribution of seismic activity, but also includes the intensity and temporal evolution characteristics of the activity.

[0100] Reference Figure 3 The specific implementation steps for the method of classifying earthquake hazard levels are as follows:

[0101] First, earthquakes are categorized into natural earthquakes, artificial earthquakes, mining earthquakes, and tsunami earthquakes. In one embodiment of the invention, the system classifies earthquake types based on factors such as earthquake waveform characteristics, occurrence time patterns, and focal depth. For example, mining earthquakes typically occur in areas with frequent mining activities and have shallow focal depths (usually <5 km); while natural tectonic earthquakes have a wider range of focal depths (ranging from tens to hundreds of kilometers).

[0102] Then, for each earthquake type, a seismic hazard level of 1 to 9 is set according to the intensity. Preferably, the system adopts the internationally recognized revised intensity scale (MMI), mapping intensity I to IX to seismic hazard levels of 1 to 9. For example, intensity I-III (slightly felt, no damage) corresponds to hazard levels 1-3, intensity IV-VI (moderately felt, slight damage) corresponds to hazard levels 4-6, and intensity VII-IX (strongly felt, severe damage) corresponds to hazard levels 7-9.

[0103] Next, the probability of earthquakes of different magnitudes occurring within a specific time period prior to the earthquake is statistically analyzed. Specifically, the frequency of earthquakes of various magnitudes within time T (e.g., 30 days) prior to the earthquake in historical data is analyzed to calculate the probability of the k-th magnitude earthquake hazard. For example, in a certain region, the probability of a magnitude 4 earthquake occurring within 30 days before a major earthquake may be 15%, the probability of a magnitude 5 earthquake may be 5%, and the probability of an earthquake of magnitude 6 or above may be less than 1%.

[0104] Then, through logarithmic normalization, a probability distribution vector of seismic hazard occurrence is generated. The system applies the following formula:

[0105] ,

[0106] Original probability Converted to normalized earthquake hazard probability .here This represents the percentage of times an earthquake occurs per hour at that location at time T before the earthquake. For example, if... ,but .

[0107] For each broadcast station i, the system generates a probability distribution vector of earthquake hazard level occurrence. Where N=9, This represents the percentage of pre-earthquake, hourly, earthquake-prone events of magnitude j occurring at the broadcasting station within time T. .

[0108] Finally, based on the probability distribution vector, the hazard level of the current earthquake is determined. The system iterates through each element in the probability distribution vector and finds the element with the highest probability. The corresponding j value represents the current earthquake hazard level. Simultaneously, the system considers the correlation between different broadcasting stations, ensuring consistency of warning levels within the region by calculating the probability distribution vector distance between stations.

[0109] Reference Figure 4 The method for determining the urgency level parameter of a broadcast is as follows:

[0110] First, the broadcast urgency level parameter is divided into three levels: 0, 1, and 2, representing low, medium, and high urgency levels, respectively. In one embodiment of the invention, 0 represents the lowest urgency level, which does not affect normal broadcasting; 1 represents a relatively high urgency level, requiring emergency preparation and evacuation when an earthquake occurs; and 2 represents an extremely high earthquake risk, the highest level, indicating that an earthquake is imminent and emergency evacuation is necessary.

[0111] Next, the broadcast urgency level parameter is calculated based on the probability of earthquake hazard occurrence through logarithmic operations. Preferably, the system uses the following formula:

[0112]

[0113] in, This parameter represents the broadcast urgency level corresponding to the earthquake hazard level of broadcast station i. This represents the maximum value element in the probability distribution vector of earthquake hazard levels for that site, where N is the total number of earthquake hazard levels (here, N=9). For example, if the maximum value in the probability distribution vector of earthquake hazard levels for a certain broadcasting site... Then its broadcast urgency parameter The system rounds this value to 1, corresponding to a medium level of urgency.

[0114] Finally, when the broadcast urgency parameter reaches a preset threshold, a corresponding level of warning response is triggered. In a preferred embodiment of the invention, the system sets the following threshold: when When, it corresponds to a level 0 response and does not affect normal broadcasting; when When this occurs, corresponding to a Level 1 response, emergency preparedness broadcasting is initiated; when When this occurs, corresponding to a Level 2 response, an emergency evacuation broadcast will be initiated. This threshold setting is based on the analysis of numerous historical earthquake cases, ensuring timely warnings while minimizing false alarms.

[0115] Reference Figure 4 The specific implementation steps for generating broadcast message encoding are as follows:

[0116] First, a three-part encoding structure consisting of a header, a body, and a tail is designed. In embodiments of the present invention, this structured design facilitates information identification, transmission, and verification, thereby improving system reliability.

[0117] The header contains synchronization characters and information identifiers. Preferably, the header uses two synchronization headers, lasting 1 second and 2 seconds respectively, to allow the receiving end to accurately identify the start position of the message. The header also includes information fields identifying the current message type and urgency level. For example, the header can use a specific byte sequence FFAA55 to represent an earthquake early warning message, while FFAAAA can represent a test message.

[0118] The main body contains multiple broadcast burst signals, encoding early warning information. In embodiments of the invention, the main body includes key information such as earthquake hazard level, epicenter location, estimated time of arrival, and recommended response measures. This information is arranged in a structured manner to ensure correct parsing by the receiving end.

[0119] The tail section contains verification information and an end marker. Preferably, the tail section uses 2 bytes to represent the end marker and includes a CRC checksum, which is used by the receiving end to verify the integrity and correctness of the message.

[0120] The complexity and length of the encoding structure are dynamically adjusted based on the broadcast urgency parameter. Specifically, when the urgency parameter is low, the system uses a complete encoding structure containing richer auxiliary information; when the urgency parameter is high, the system simplifies the encoding structure, retaining only the most essential information to accelerate transmission. For example, when the urgency level is 2, the main body may only contain the hazard level and estimated arrival time, omitting detailed source information.

[0121] Reference Figure 4 The specific steps for generating a broadcast burst signal are as follows:

[0122] First, the duration of the broadcast burst signal is calculated based on the broadcast urgency parameter. In an embodiment of the invention, the system uses the formula:

[0123] ,

[0124] in, Indicates the duration of a broadcast burst signal (in seconds). This parameter indicates the broadcast urgency level corresponding to the seismic hazard level of the site. For example, if... ,but seconds, meaning each broadcast burst lasts approximately .

[0125] Then, the interval for repeating broadcast messages is determined. Preferably, the system uses the formula:

[0126] ,

[0127] in, This indicates the interval between broadcast message repetitions (in seconds). This design ensures that the broadcast message repetition interval is 95% of the burst signal duration, guaranteeing the continuity of information transmission. For example, if... seconds, then Second.

[0128] Next, the broadcast message encoding is converted into a hexadecimal number sequence. The system converts every two bytes in the broadcast message encoding into a hexadecimal number. For example, the binary encoding 1010110100110111 can be converted into hexadecimal AD37.

[0129] Then, the hexadecimal number sequence is grouped and converted into quinary characters. Preferably, the system converts the hexadecimal number sequence into quinary characters in groups of 5. This step further compresses the data volume while increasing the concealment of information.

[0130] Next, the pentadecimal characters are converted into ASCII character sequences. The system maps pentadecimal characters to printable characters in the ASCII table, enabling information to be transmitted across various communication channels.

[0131] Finally, using pulse width modulation (PWM), the ASCII code is converted into a digital level sequence to generate broadcast burst signals corresponding to different frequencies. Preferably, the system calculates the broadcast burst signal frequency using the following formula:

[0132] ,

[0133] in, This represents the frequency (in Hertz) of the broadcast burst signal corresponding to the i-th group of digital level sequences. This represents the value of the i-th group of digital level sequences. This indicates the frequency of the basic broadcast burst signal (usually set to 300Hz). , , , It is a constant (typical value is) , , , This design allows different warning messages to have different frequency characteristics, enhancing signal recognizability and anti-interference capabilities. For example, when... At that time, the corresponding signal frequency is approximately 315Hz; when At that time, the corresponding signal frequency was approximately 348 Hz.

[0134] The specific implementation steps of the power line carrier transmission method are as follows:

[0135] First, the broadcast message is encoded and converted into an electrical signal. In an embodiment of the invention, the system uses a digital-to-analog converter to convert the digital code into an analog electrical signal, typically with a voltage range of 0-5V and a frequency range of 100Hz-1kHz.

[0136] Then, the electrical signal is modulated onto the mains signal using digital zero-crossing and quadrature modulation methods. Specifically, the system outputs coded information at the quadrature position of the zero signal in each cycle of the mains signal (usually a 50Hz or 60Hz sine wave). When the output is 1, it indicates that a ground motion warning message has been sent; when the output is 0, it indicates that no ground motion warning message has been sent.

[0137] A significant advantage of this modulation method is its minimal impact on normal power supply to the grid, because the modulating signal is mainly applied near the zero-crossing point, and grid equipment is not sensitive to signal changes in this area. Furthermore, due to the characteristics of quadrature modulation, the signal has strong anti-interference capabilities.

[0138] Next, encoded information is output at the orthogonal position of the zero signal in each cycle of the mains signal. Preferably, the system encodes one bit of information within each mains cycle (20ms for a 50Hz mains grid), achieving a basic transmission rate of 50bps. In practical applications, this parameter can be adjusted according to the grid quality and transmission distance; for example, it can be increased to 100bps in high-quality grids, while it can be reduced to 25bps in areas with poor grid quality to ensure reliability.

[0139] The modulated mains signal is then transmitted to the broadcast receiving device via the power grid. This step makes full use of existing power infrastructure, eliminating the need for an additional dedicated network and significantly reducing system deployment costs and complexity.

[0140] Finally, the earthquake early warning information and broadcast signal are demodulated in the broadcast receiving device. Preferably, the receiving device first filters the amplitude and frequency of the mains signal, then performs analog-to-digital conversion, and performs correlation calculations with a preset reference signal. After determining that the information matches successfully, the early warning information and broadcast signal are demodulated.

[0141] In one embodiment of the present invention, the relevant calculations are performed using the following formula:

[0142] ,

[0143] in, For the relevant calculation results, It is a digital signal. For reference signal, for The number of sample points. If If the received digital signal is a match, then the match is considered successful. For example, if the received digital signal... Reference signal ,but Match successful.

[0144] The specific steps for a wireless repeater to forward broadcast messages are as follows:

[0145] First, the wireless transmitter sends the broadcast message to the wireless repeater. In embodiments of the present invention, the wireless transmitter is typically located at an earthquake monitoring center or early warning information processing center, and sends the encoded early warning information to wireless repeaters distributed in various areas via a dedicated wireless link (usually using the 400MHz or 900MHz frequency band).

[0146] Then, the wireless repeater sends a connection request to the wireless communication network. Preferably, the repeater uses a specific request message format, including fields such as repeater ID, request type, and priority identifier. For example, connection requests for emergency warning messages can be set to the highest priority to ensure priority allocation of network resources.

[0147] Next, the connection response from the wireless communication network is received. After verifying the legitimacy of the connection request, the network core device returns a connection response message to the repeater, which includes resource allocation information, communication parameters, etc.

[0148] Then, the wireless repeater receives and transmits the broadcast message through the wireless communication network. In one embodiment of the invention, the repeater can simultaneously send messages to multiple downstream nodes (such as broadcast stations) in parallel, improving propagation efficiency. For example, a repeater can simultaneously send warning messages to 20 to 30 broadcast stations within its coverage area.

[0149] Finally, after transmission is complete, an exit request is sent to the wireless communication network and an exit response is received. This step ensures that network resources are released in a timely manner, while providing a clear indication of the end of the session and avoiding problems caused by unclear information transmission status.

[0150] In a preferred embodiment of the present invention, the wireless communication network can be implemented using various technologies, such as dedicated emergency communication networks, public mobile communication networks (e.g., 4G / 5G), and low-power wide-area networks (LPWAN). The system will select the most suitable wireless technology based on regional characteristics and coverage requirements, and can achieve multi-network convergence, further improving the system's reliability and coverage.

[0151] Reference Figure 5 The specific steps for emergency response procedures for broadcast receivers are as follows:

[0152] First, a broadcast warning message is played. In an embodiment of the invention, after receiving the warning message, the broadcast receiver sets the corresponding playback priority and volume according to the urgency level parameter obtained from decoding. For example, when the urgency level is 2 (the highest level), the system automatically turns the volume up to the maximum and interrupts all other content that is playing.

[0153] Then, it receives emergency operation request signals. Preferably, the system provides multiple emergency operation interfaces, including physical buttons (such as emergency operation keys) and software interfaces (such as remote control commands). When a user or administrator needs to perform a specific emergency operation, they can send a request signal through these interfaces.

[0154] Next, the broadcast is paused to receive emergency instructions. The system temporarily suspends the broadcast of warning information, awaiting the input of emergency instructions. In a preferred embodiment of the invention, the maximum pause time is 30 seconds; after this time, the system automatically resumes broadcasting, ensuring that critical warning information is not interrupted for an extended period.

[0155] Then, the system executes corresponding operations based on the emergency instructions. The system supports various emergency operations, such as adjusting broadcast content (e.g., adding localized evacuation guidelines), modifying broadcast frequency, switching to backup power, and activating auxiliary warning devices (e.g., flashlights). For example, in a school setting, the administrator can send instructions to add specific guidance for students to evacuate to the playground in an orderly manner according to their classes.

[0156] Finally, after completing the emergency procedures, the broadcast warning information continues to play. The system resumes broadcasting warning information to ensure the public continues to receive critical information. Preferably, the system inserts a brief prompt tone before resuming broadcasting to attract public attention.

[0157] In embodiments of the present invention, the broadcast receiver adopts a modular design, including a power management module, a signal receiving module, a decoding processing module, an audio playback module, and a human-computer interaction module. The modules are connected via standardized interfaces, achieving functional decoupling and flexible configuration. For example, different power audio playback modules can be selected for different scenarios, ranging from low-power household speakers (10-30W) to high-power public speakers (100-500W), meeting different coverage requirements.

[0158] This invention provides an earthquake early warning method for an emergency early warning broadcast system. By innovatively combining topological spatial mapping, probability field theory, and fractal coding technologies, a complete earthquake early warning technology system is constructed. This method features an innovative design across the entire process, from spatial mapping and risk assessment to information coding and signal transmission, with each stage working closely together to form a highly integrated technical solution.

[0159] This invention solves the key problems faced by traditional earthquake early warning systems, such as poor accuracy, low reliability, and insufficient transmission efficiency. It features precise determination of the early warning range, scientific assessment of earthquake risk, and efficient encoding and transmission of early warning information, which greatly improves the accuracy, timeliness, and reliability of earthquake early warning.

[0160] It should be noted that the above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A seismic early warning method of an emergency warning broadcast system, characterized by, The method comprises the following steps: obtaining the longitude and latitude coordinates of the seismic source and seismic monitoring data; determining the distribution area range of the broadcast station based on the longitude and latitude coordinates of the seismic source, wherein the range is expressed by longitude and latitude; constructing a seismic risk topological space based on historical seismic data, and dividing the seismic risk level in the topological space; determining the corresponding broadcast emergency level parameter according to the seismic risk level, and generating a broadcast message code; sending the broadcast message code to the broadcast station in the broadcast station distribution area through power line carrier and wireless communication network to trigger the earthquake early warning broadcast; the step of constructing a seismic risk topological space based on historical seismic data comprises: obtaining historical seismic data, extracting time, location and intensity key features; mapping the historical seismic data in the time-space-intensity three-dimensional space to form a seismic data point distribution; conducting density analysis on the seismic data point distribution to identify high-risk areas; constructing a seismic risk topological space according to the distribution characteristics of the high-risk areas; the step of dividing the seismic risk level comprises: dividing the earthquake type into natural earthquake, artificial earthquake and mine earthquake; for each type of earthquake, setting the seismic risk level from 1 to 9 according to the intensity; statistical the occurrence probability of different levels of earthquakes in a certain period of time before the earthquake; generate a seismic risk probability distribution vector by logarithmic normalization processing; determine the risk level of the current earthquake based on the probability distribution vector.

2. The method of claim 1, wherein, The step of determining the distribution area range of the broadcast station based on the longitude and latitude coordinates of the seismic source comprises: obtaining the maximum and minimum latitude and longitude of the broadcast station distribution, and calculating the actual geographical coverage range of the broadcast station distribution area according to the maximum and minimum values combined with the curvature factor of the earth; based on the geological structure data, the coverage range is corrected to obtain the final broadcast station distribution area range. The step of determining the corresponding broadcast emergency level parameter according to the seismic risk level comprises:

3. The method of claim 1, wherein, dividing the broadcast emergency level parameter into 0, 1 and 2 levels, respectively representing low, medium and high emergency level; calculate the broadcast emergency level parameter based on the seismic risk probability by logarithmic operation; when the broadcast emergency level parameter reaches the preset threshold, trigger the corresponding level of early warning response. The step of generating a broadcast message code comprises:

4. The method of claim 1, wherein, designing a three-part coding structure including header, body and tail; the header contains synchronization characters and information identification; the body part contains a plurality of broadcast burst signals, encoding warning information content; the tail contains check information and end mark; according to the broadcast emergency level parameter, dynamically adjust the complexity and length of the coding structure. The generation of the broadcast burst signal comprises:

5. The method of claim 4, wherein, calculate the broadcast burst signal duration according to the broadcast emergency level parameter; determine the broadcast message repetition interval time; convert the broadcast message code into a hexadecimal number sequence; group the hexadecimal number sequence into a quinary character; convert the quinary character to an ASCII code character sequence; ​ The ASCII code is converted into a level digital sequence by pulse width modulation to generate broadcast burst signals corresponding to different frequencies.

6. The method of claim 1, wherein, The step of encoding the broadcast message for transmission through power line carrier includes: Converting the broadcast message code into an electrical signal; Using digital zero-crossing and signal quadrature modulation method to modulate the electrical signal onto the mains signal; Outputting the encoded information at the quadrature position of the zero signal in each cycle of the mains signal; Transmitting the modulated mains signal through the power network to the broadcast receiving device; Demodulating the earthquake warning information and broadcast signal in the broadcast receiving device.

7. The method of claim 1, wherein, The step of forwarding the broadcast message through a wireless relay station includes: The wireless transmitter sends the broadcast message to the wireless relay station; The wireless relay station sends a connection request to the wireless communication network; Receiving the connection response from the wireless communication network; The wireless relay station receives and sends the broadcast message through the wireless communication network; After sending, send a quit request to the wireless communication network and receive a quit response.

8. The method of claim 1, wherein, The step of the broadcast receiver responding to the emergency operation includes: Playing the broadcast warning information; Receiving the emergency operation request signal; Pausing the broadcast information and receiving the emergency instruction; Performing the corresponding operation according to the emergency instruction; After completing the emergency operation, continue to play the broadcast warning information.

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