A real-time return method for semi-airborne transient electromagnetic data for landslide detection

Abstract

This invention belongs to the field of ground-to-air transient electromagnetic measurement technology using magnetic sources, and more particularly relates to a semi-aerial transient electromagnetic data real-time transmission method suitable for landslide detection. This method utilizes an unmanned aerial vehicle (UAV) platform for rapid flight, automatically forming and superimposing tracks in mid-air, and obtaining kilobyte-level measured data. This data is then transmitted back to a ground receiving station in real time via wireless communication, facilitating real-time data processing. This method can provide faster interpretation results than conventional methods during landslide geological disaster surveys, providing a basis for disaster management in emergency landslide situations.

Description

Technical Field

[0001] The invention belongs to the technical field of ground-to-air transient electromagnetic measurement using a magnetic source, and in particular relates to a real-time return method of semi-aerial transient electromagnetic data suitable for landslide detection. Background Art

[0002] Semi-airborne transient electromagnetic (SATEM) involves transmitting data from the ground and placing the receiving system on an aerial platform for efficient and rapid data acquisition. This method offers a balanced balance between detection depth and efficiency, making it a hot topic in deep exploration research in recent years. Research has shown that SATEM has significant potential for application in the fields of mineral exploration, oil and gas exploration, and geological disasters.

[0003] While research and application testing of semi-airborne transient electromagnetic (STEM) have been conducted both domestically and internationally, encompassing flight platforms, transmitters, data acquisition methods, and data processing, there is limited research on its application in the rapid investigation of geological hazards such as landslides and collapses. Typical geological hazards such as landslides often occur in mountainous areas, characterized by complex terrain, loose surfaces, significant rainfall impacts, and sudden onset. Therefore, ground-based geophysical methods are difficult to implement under these conditions. Airborne electromagnetic methods, which require dedicated airports for takeoff and landing, operate at speeds of 200 km / h, and typically fly at altitudes of 100 meters, are unsuitable for rapid investigations of small-scale landslides and geological hazards.

[0004] Previous research has shown that the semi-airborne transient electromagnetic method, using a rotary-wing drone as a flight platform carrying a receiver, typically flies at speeds of 1-5 m / s and altitudes below 50 m. It can take off directly from the site, eliminating the need for a dedicated airport. This makes it ideal for rapid investigations of small-scale landslide geological hazards. However, current semi-airborne transient electromagnetic receiving systems typically employ full-waveform continuous sampling, meaning that sampling is performed continuously at 4μs intervals without synchronization with the transmitter. Within just one second, 2.5 million data points must be collected and stored per cycle. Even for a small-scale survey, the measured data volume can reach a massive level within tens of minutes. Under full-waveform sampling, non-secondary field signals in the on-time and ramp-time segments account for more than half of the total data, and a small portion of late data in the off-time segment is noise and unusable. Consequently, under these full-waveform acquisition conditions, only 30-40% of the data is usable secondary field data. Subsequent data processing consumes a significant portion of the time spent on channel selection, channel grouping, data conversion, and correction, resulting in significant human influence, making it difficult to quickly provide survey results in geological disaster emergencies.

[0005] Therefore, the currently used semi-airborne transient electromagnetic data acquisition method and processing technology cannot meet the geological needs of rapid data transmission, processing and interpretation in geological disaster emergencies. Summary of the Invention

[0006] The present invention provides a real-time return method for semi-aerial transient electromagnetic data suitable for landslide detection. The purpose is to implement measurements in landslide geological disasters. It can provide faster interpretation results than conventional methods and provide a basis for disaster management in emergency situations of landslide geological disasters.

[0007] To achieve the above object, the technical solution adopted by the present invention is:

[0008] A method for real-time return of semi-airborne transient electromagnetic data suitable for landslide detection includes the following steps:

[0009] S1. Equip the semi-aeronautical transient electromagnetic launch system with high-precision GPS and data transmission devices;

[0010] S2. Set the transmission parameters, including time base, falling edge, transmission current, etc.

[0011] S3. Configure the semi-aeronautical transient electromagnetic receiving system with a high-precision GPS and a data transmission receiving device, and synchronize the semi-aeronautical transient electromagnetic receiving system with the GPS of the semi-aeronautical transient electromagnetic transmitting system;

[0012] S4. In the acquisition mode of the semi-aeronautical transient electromagnetic receiving system, a logarithmically equally spaced data acquisition time window is set in the off-time segment;

[0013] S5. Sample at 4us, group the data within a time base range according to the time window, and perform superposition and averaging according to the set superposition times to obtain a set of transient response data for the current measuring point, and save it at the current point number.

[0014] S6, transmitting the transient electromagnetic data of the current point number to the digital transmission device of the receiving system through the serial port;

[0015] S7, the digital transmission transmitting device transmits the transient electromagnetic data to the digital transmission receiving device;

[0016] S8. The data transmission receiving device is connected to the ground receiving station. After receiving the transient electromagnetic data, the data is transmitted to the receiving station and saved according to the origin number.

[0017] S9. The semi-aerial transient electromagnetic transmitting system is based on the semi-aerial transient electromagnetic receiving system. It quickly collects data along the designed survey line in the air and continuously transmits the measured data to the ground receiving station until the overall measurement is completed.

[0018] Furthermore, in step S1, the transmission frequency of the data transmission device is 928 MHz.

[0019] Furthermore, in step S2, the time base is 10ms, the falling edge is 50μs, and the emission current is 20A.

[0020] Furthermore, in step S3, the GPS of the semi-aeronautical transient electromagnetic receiving system and the semi-aeronautical transient electromagnetic transmitting system are synchronized with a synchronization accuracy of 1 μs.

[0021] Furthermore, in step S4, under the condition of a 10 ms time base, the time window is 26 channels, 14 μs-6.25 ms.

[0022] Furthermore, in step S5, when the time window is 26 channels, the data volume is about 150 bytes.

[0023] Compared with the prior art, the present invention has the following beneficial effects:

[0024] The present invention achieves synchronization by equipping both the semi-aeronautical transient electromagnetic transmitting system and the semi-aeronautical transient electromagnetic receiving system with high-precision GPS, accurately determining the falling edge of the transmitting waveform and ensuring that only data in the off-time segment is collected. During sampling, the channel grouping technology is adopted to group the data within a time base range according to the time window and superimpose them according to the set number of superpositions, thereby massively compressing the data volume. The limited measured data is transmitted back to the ground receiving station in real time using a digital transmission transmitting device and a digital transmission receiving device. The ground receiving station can provide the inversion results in real time using fast imaging technology. For the detection conditions of conventional landslides in small areas, the data volume can be reduced, and the real-time data processing is facilitated. When implementing measurements on landslide geological disasters, it can provide faster interpretation results than conventional methods, providing a basis for disaster management in emergency situations of landslide geological disasters. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 Schematic diagram of data transmission between the semi-aeronautical transient electromagnetic transmitting system and the semi-aeronautical transient electromagnetic receiving system. DETAILED DESCRIPTION

[0026] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0027] like Figure 1 As shown, a real-time return method for semi-airborne transient electromagnetic data suitable for landslide detection includes the following steps:

[0028] S1. Equip the semi-aeronautical transient electromagnetic launch system with high-precision GPS and data transmission devices;

[0029] S2. Set the transmission parameters, including time base, falling edge, transmission current, etc.

[0030] S3. Configure the semi-aeronautical transient electromagnetic receiving system with a high-precision GPS and a data transmission receiving device, and synchronize the semi-aeronautical transient electromagnetic receiving system with the GPS of the semi-aeronautical transient electromagnetic transmitting system;

[0031] S4. In the acquisition mode of the semi-aeronautical transient electromagnetic receiving system, a logarithmically equally spaced data acquisition time window is set in the off-time segment;

[0032] S5. Sample at 4us, group the data within a time base range according to the time window, and perform superposition and averaging according to the set superposition times to obtain a set of transient response data for the current measuring point, and save it at the current point number.

[0033] S6, transmitting the transient electromagnetic data of the current point number to the digital transmission device of the receiving system through the serial port;

[0034] S7, the digital transmission transmitting device transmits the transient electromagnetic data to the digital transmission receiving device;

[0035] S8. The data transmission receiving device is connected to the ground receiving station. After receiving the transient electromagnetic data, the data is transmitted to the receiving station and saved according to the origin number.

[0036] S9. The semi-aerial transient electromagnetic transmitting system is based on the semi-aerial transient electromagnetic receiving system. It quickly collects data along the designed survey line in the air and continuously transmits the measured data to the ground receiving station until the overall measurement is completed.

[0037] The present invention is further described in detail below with reference to examples:

[0038] S1. The semi-aeronautical transient electromagnetic transmission system is equipped with a high-precision GPS and a data transmission device, and the transmission frequency of the data transmission device is 928MHz;

[0039] S2. Set the transmission parameters: time base is 10ms, falling edge is 50μs, and transmission current is 20A;

[0040] S3. Configure the semi-aeronautical transient electromagnetic receiving system with a high-precision GPS and a data transmission receiving device. The semi-aeronautical transient electromagnetic receiving system is synchronized with the GPS of the semi-aeronautical transient electromagnetic transmitting system with a synchronization accuracy of 1μs.

[0041] In the acquisition mode of S4 and semi-aeronautical transient electromagnetic receiving systems, logarithmically equally spaced data acquisition time windows are set in the off-time segment (within 10ms). Under the 10ms time base condition, the time window is 26 channels, 14μs-6.25ms;

[0042] S5. Sample at 4us and group the data within a time base range according to the time window. Then, perform superposition and averaging according to the set number of superpositions to obtain a set of transient response data for the current measuring point. The data volume of 26 channels is about 150 bytes and is saved at the current point number 0001.

[0043] S6, transmitting the transient electromagnetic data of the current point number 0001 to the digital transmission device of the semi-aeronautical transient electromagnetic receiving system through the serial port;

[0044] S7, the digital transmission transmitting device transmits the transient electromagnetic data to the digital transmission receiving device;

[0045] S8. The data transmission receiving device is connected to the ground receiving station. After receiving the transient electromagnetic data, the data is transmitted to the receiving station and saved according to the origin number.

[0046] S9. The semi-aerial transient electromagnetic transmitting system is based on the semi-aerial transient electromagnetic receiving system. It quickly collects data along the designed survey line in the air and continuously transmits the measured data to the ground receiving station until the overall measurement is completed.

[0047] The preferred embodiments of the present invention disclosed above are intended only to help illustrate the present invention. These preferred embodiments do not exhaustively describe all details, nor do they limit the present invention to the specific embodiments described. Obviously, many modifications and variations are possible based on the content of this specification. These embodiments are selected and described in detail in this specification to better explain the principles and practical applications of the present invention, thereby enabling those skilled in the art to better understand and utilize the present invention. The present invention is limited only by the claims and their full scope and equivalents.

Claims

1. A method for real-time return of semi-airborne transient electromagnetic data suitable for landslide detection, characterized in that: The following steps are involved: S1. Equip the semi-aeronautical transient electromagnetic launch system with high-precision GPS and data transmission devices; S2. Set the transmission parameters, including time base, falling edge, and transmission current; S3. Configure the semi-aeronautical transient electromagnetic receiving system with a high-precision GPS and a data transmission receiving device, and synchronize the semi-aeronautical transient electromagnetic receiving system with the GPS of the semi-aeronautical transient electromagnetic transmitting system; S4. In the acquisition mode of the semi-aeronautical transient electromagnetic receiving system, a logarithmically equally spaced data acquisition time window is set in the off-time segment; S5. Sample at 4us, group the data within a time base range according to the time window, and perform superposition and averaging according to the set superposition times to obtain a set of transient response data for the current measuring point, and save it at the current point number. S6, transmitting the transient electromagnetic data of the current point number to the digital transmission device of the receiving system through the serial port; S7, the digital transmission transmitting device transmits the transient electromagnetic data to the digital transmission receiving device; S8. The data transmission receiving device is connected to the ground receiving station. After receiving the transient electromagnetic data, the data is transmitted to the receiving station and saved according to the origin number. S9. The semi-aerial transient electromagnetic transmitting system is based on the semi-aerial transient electromagnetic receiving system. It quickly collects data along the designed survey line in the air and continuously transmits the measured data to the ground receiving station until the overall measurement is completed.

2. The method for real-time transmission of semi-airborne transient electromagnetic data suitable for landslide detection according to claim 1, characterized in that: In step S1, the transmission frequency of the data transmission device is 928 MHz.

3. The method for real-time transmission of semi-airborne transient electromagnetic data suitable for landslide detection according to claim 2, characterized in that: In step S2, the time base is 10ms, the falling edge is 50μs, and the emission current is 20A.

4. The method for real-time transmission of semi-airborne transient electromagnetic data suitable for landslide detection according to claim 3 is characterized in that: In step S3, the GPS of the semi-aeronautical transient electromagnetic receiving system and the semi-aeronautical transient electromagnetic transmitting system are synchronized with a synchronization accuracy of 1 μs.

5. The method for real-time transmission of semi-airborne transient electromagnetic data suitable for landslide detection according to claim 4, characterized in that: In step S4, under the condition of a 10 ms time base, the time window is 26 channels, 14 μs-6.25 ms.

6. The method for real-time transmission of semi-airborne transient electromagnetic data suitable for landslide detection according to claim 5, characterized in that: In step S5, when the time window is 26 channels, the data volume is about 150 bytes.

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