Homologous multi-channel pseudolite deformation monitoring system in GNSS denial environment

Abstract

The application provides a homologous multi-channel pseudolite deformation monitoring system in a GNSS denial environment and relates to the field of geological deformation early warning and monitoring. The device comprises a pseudolite base station module, a transmitting antenna module, an infrared distance measuring module, a monitoring receiver, a monitoring data processing center and a high-definition camera device. The monitoring receiver is used for receiving Beidou micro base station signal output carrier phase observation, and carrier phase double difference data are used for monitoring deformation. Since the carrier phase difference fluctuation is small, when a mountain or the like is deformed, the recognition degree is high. Meanwhile, the system is provided with a high-definition camera device, when the carrier phase double difference data change greatly, the high-definition camera device is used for fixed-point checking and detecting the position of the receiver, and further deformation confirmation is performed.

Description

Technical Field

[0001] The present invention relates to the field of geological deformation early warning monitoring in situations such as landslides, deformations, and depressions under GNSS denial conditions, and specifically refers to a homologous multi-channel pseudo-satellite deformation monitoring system under GNSS denial conditions. Background Art

[0002] With the construction of more and more railways and bridges, safety accidents caused by problems such as landslides and bridge collapses are also increasing. At present, the main way to deal with this problem is to use GPS differential technology to monitor landslides, bridge collapses and other problems. That is, by establishing differential stations, the monitoring receiver receives GNSS signals and differential information to perform high-precision positioning. However, in a GNSS-denied environment, how to solve the problem of address deformation monitoring and early warning is still quite difficult.

[0003] Pseudolites, by broadcasting GNSS-like signals, can replace navigation satellites in areas where GNSS signals are not available. Their simple structure, compact size, and ease of deployment make them an excellent alternative to navigation satellites. Furthermore, pseudolite positioning technology is becoming increasingly mature, achieving ever-increasing accuracy. Carrier phase-based positioning can achieve centimeter-level accuracy, meeting the requirements for geological deformation detection. Summary of the Invention

[0004] The technical problem to be solved by the present invention is to provide a homologous multi-channel pseudo-satellite deformation monitoring system, which uses its high stability and high positioning accuracy to solve the problems of geological deformation monitoring and early warning in GNSS-denied environments.

[0005] The technical solution adopted in the present invention is:

[0006] A homologous multi-channel pseudolite deformation monitoring system in a GNSS-denied environment, comprising:

[0007] Pseudo-satellite base station module, including multiple signal channels, using the same clock source between channels; used to broadcast GNSS-like signals through the transmitting antenna to cover the monitored area;

[0008] The transmitting antenna module consists of multiple transmitting antennas, which are connected to the pseudo-satellite base station module via radio frequency cables. Each transmitting antenna corresponds to one signal channel. Multiple transmitting antennas are arranged with short spacing between them and erected on a tower at a specific height.

[0009] The infrared ranging module is installed together with the transmitting antenna module to measure the height of the transmitting antenna from the ground. It is used to monitor whether the transmitting antenna module moves in real time and report the status to the server through the built-in IoT card.

[0010] The monitoring receiver is installed at multiple fixed points in the monitored area to receive multiple GNSS-like signals transmitted by the pseudo-satellite base station module and upload the raw observation information of the received multiple GNSS-like signals to the monitoring data processing center through the built-in Internet of Things card;

[0011] The monitoring data processing center includes a deformation monitoring unit and a monitoring data reporting unit. The deformation monitoring unit is used to perform real-time data processing on the original observation information uploaded by the monitoring receiver, analyze and calculate the position change of the monitoring receiver, calculate the deformation degree, and send it to the server through the monitoring data reporting unit;

[0012] The high-definition camera device is used to check the deformation of the corresponding monitoring receiver installation point at a fixed point under the control of the server.

[0013] Furthermore, it also includes a solar panel, which uses solar power to power the pseudo-satellite base station module and the monitoring receiver; the infrared ranging module is powered by a battery.

[0014] Furthermore, the monitoring data reporting unit includes a storage module and a 4G communication module. The storage module is used to store monitoring data in real time, and the 4G communication module is used to report monitoring results in real time and issue early warnings.

[0015] Furthermore, the specific processing process of the deformation monitoring unit includes:

[0016] (1) Obtain in real time the carrier phase of multiple GNSS-like signal raw observation information uploaded by a monitoring receiver at a fixed point and record it;

[0017] (2) Subtract the phases of multiple carrier waves from each other and calculate the average value, which serves as a reference value for determining whether deformation occurs.

[0018] The difference formula is:

[0019] Δφ n-m (i) = φ n (i)-φ m (i) (1)

[0020] Where, φ n (i) and φ m (i) are the carrier phases of satellites n and m at the i-th epoch, Δφ n-m (i) is the carrier phase difference between satellite n and satellite m at epoch i;

[0021] According to formula (1), the reference value is:

[0022]

[0023] Where, is the average value of the carrier phase difference between satellite n and satellite m over N epochs, which serves as a reference value;

[0024] (3) Subtract the current carrier phase difference from the current reference value;

[0025] The difference calculation formula is:

[0026]

[0027] Where Δφ n-m (H) is the carrier phase difference at the current epoch H, The difference between the real-time monitored carrier phase difference and the reference value;

[0028] (4) When When more than half of them are greater than the monitoring threshold, it is determined that deformation has occurred and an early warning is issued; if no deformation has occurred, the current reference value and the carrier phase difference are summed and averaged as the new reference value, and then return to step (3); the calculation formula is as follows:

[0029]

[0030] The advantages of the present invention compared to the prior art are:

[0031] The pseudo-satellite base station of the present invention includes multiple channels, each of which uses the same clock source, achieving strict signal synchronization between the channels and ensuring that the original observation information of different pseudo-satellite signals output by the monitoring receiver has the same changes. Secondly, a multi-channel pseudo-satellite can transmit multiple navigation signals, and each channel corresponds to a transmitting antenna. The transmitting antennas are arranged with a short spacing. Compared with other current pseudo-satellite monitoring methods, there is no need to deploy base stations at multiple points over a large area. Only one multi-channel pseudo-satellite needs to be deployed at a fixed point. The multiple antennas are arranged with a short spacing, avoiding the near-far effect caused by multi-point distribution, which can improve positioning accuracy. Moreover, the multiple antennas adopt a short spacing layout, and the signal space transmission channel state is consistent. The receiver receives and analyzes the original observation information of the pseudo-satellite, which has high stability and accuracy. Secondly, the multi-channel pseudo-satellite has the advantages of being small in size and easy to deploy. Moreover, the deformation monitoring method based on the homologous multi-channel pseudo-satellite has high positioning accuracy, greatly increasing the reliability of deformation monitoring. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] Figure 1 Schematic diagram of a monitoring system according to an embodiment of the present invention.

[0033] Figure 2 Schematic diagram of a transmitting antenna module according to an embodiment of the present invention. DETAILED DESCRIPTION

[0034] The technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all the embodiments.

[0035] like Figure 1 , a homologous multi-channel pseudolite deformation monitoring system in a GNSS-denied environment, specifically as follows:

[0036] Select a stable point in a flat area around the monitored area and build a transmission tower. The tower's height must ensure that the pseudolite signal can cover the entire monitored area. Then, build a control room at the base of the tower and deploy the pseudolite base station module. The pseudolite base station module contains multiple signal channels, all of which use the same clock source. The pseudolite base station broadcasts GNSS-like signals through the transmitting antenna, thereby covering the monitored area.

[0037] The pseudolite base station is further equipped with a 4G communication module and a pseudolite status monitoring module. The pseudolite status monitoring module monitors the operating status of the pseudolite in real time and reports the operating status of the pseudolite to the server in real time through the 4G communication module.

[0038] The transmitting antenna module consists of multiple transmitting antennas, which are connected to the pseudo-satellite base station module through radio frequency cables. Each transmitting antenna corresponds to one signal channel. Multiple antennas are arranged with short spacing, vertically on the ground, and facing the mountain. Figure 2 As shown, a rectangular structure is used. 4 antennas are arranged up and down with a spacing of 5 meters. The spacing length is related to the monitoring range. 2 antennas are arranged at the top and 2 antennas are arranged at the bottom. The length of the long side is related to the coverage range. The schematic diagram of the transmitting antenna module is shown in Figure 2 shown.

[0039] The infrared ranging module, installed together with the transmitting antenna module, measures the height of the transmitting antenna from the ground. This prevents external factors such as wind and rain from causing the transmitting antenna to move and thus cause false warnings. It is used to monitor the movement of the transmitting antenna module in real time and report the status to the server via the built-in IoT card.

[0040] The monitoring receiver is installed at multiple fixed points in the monitored area to receive multiple signals transmitted by pseudo-satellites. The monitoring receiver has a built-in Internet of Things card and can upload the received original observation information to the monitoring data processing center via the wireless network.

[0041] The monitoring data processing center includes a deformation monitoring unit and a monitoring data reporting unit. The deformation monitoring unit processes the original observation information uploaded by the monitoring receiver in real time, analyzes and calculates the position of the monitoring receiver, obtains the deformation degree, and sends it to the server through the monitoring data reporting unit.

[0042] The monitoring data reporting unit includes a storage module and a 4G communication module. The storage module stores the monitoring data in real time, and the 4G communication module reports the monitoring results in real time for early warning.

[0043] A high-definition camera device is installed on the transmission tower. When the server receives the monitoring data uploaded by the monitoring data reporting unit, if a monitoring alarm occurs, the server controls the high-definition camera device to check the situation of the corresponding receiver installation point. If deformation does occur, emergency treatment is carried out. If it is a false alarm, an alarm is triggered.

[0044] Furthermore, the deformation monitoring system is also equipped with solar panels, which use solar power to power the pseudo-satellite base station and the monitoring receiver; and the infrared ranging module is powered by a battery and has a power prompt function.

[0045] Furthermore, the data processing in the deformation monitoring unit includes the following steps:

[0046] 1. Obtain in real time the carrier phase information of multiple pseudo-satellite signal raw observations uploaded by a monitoring receiver at a fixed point and record its value.

[0047] 2. The carrier phases of multiple pseudolites are initially subtracted from each other, serving as a reference for determining deformation. This difference is then compared with the current value. Due to the homologous design, clock deviations and drifts between multiple signals are consistent after subtraction, eliminating them, resulting in highly stable values. If the difference exceeds the monitoring threshold, an alert is issued, notifying personnel for inspection. If no change is observed, the current data is averaged with the reference value, serving as the reference for determining deformation at the next moment. This process is repeated.

[0048] The difference formula is as follows:

[0049] Δφ n-m (i) = φ n (i)-φ m (i) (1)

[0050] Where, φ n (i),φ m (i) are the carrier phases of satellites n and m at the i-th epoch, Δφ n-m (i) is the carrier phase difference between satellite n and satellite m at the i-th epoch.

[0051] According to formula (1), the initial reference value is

[0052]

[0053] is the average value of the carrier phase difference between satellite n and satellite m over N epochs.

[0054] 3. Subtract the current carrier phase difference from the current reference value;

[0055] The difference calculation formula is:

[0056]

[0057] Where Δφ n-m (H) is the carrier phase difference at the current epoch H, The difference between the real-time monitored carrier phase difference and the reference value is the difference between the real-time monitored carrier phase difference and the reference value. Since four antennas are deployed, There are 6 differences.

[0058] 4. Generally speaking, when the pseudo satellite base station uses a constant temperature crystal oscillator, the fluctuation of the carrier phase difference is ±0.01, so when If more than half of the six differences are greater than 0.01, deformation is determined to have occurred. If no deformation has occurred, the current monitoring value and the carrier phase difference of the initial multiple epochs are summed as the new reference value, and then the process returns to 3 for continuous iteration; the formula is as follows:

[0059]

[0060] The above is only a specific example of the present invention, but the protection scope of the present invention is not limited thereto. Within the technical scope disclosed by the present invention, any changes that can be understood and thought of should be included in the scope of the present invention.

Claims

1. A homologous multi-channel pseudolite deformation monitoring system in a GNSS-denied environment, characterized by: include: Pseudo-satellite base station module, including multiple signal channels, using the same clock source between channels; Used to broadcast GNSS-like signals through the transmitting antenna to cover the monitored area; The transmitting antenna module consists of multiple transmitting antennas, which are connected to the pseudo-satellite base station module via radio frequency cables. Each transmitting antenna corresponds to one signal channel. Multiple transmitting antennas are arranged with short spacing between them and are erected on a tower at a specific height. The infrared ranging module is installed together with the transmitting antenna module to measure the height of the transmitting antenna from the ground. It is used to monitor whether the transmitting antenna module moves in real time and report the status to the server through the built-in IoT card. The monitoring receiver is installed at multiple fixed points in the monitored area to receive multiple GNSS-like signals transmitted by the pseudo-satellite base station module and upload the raw observation information of the received multiple GNSS-like signals to the monitoring data processing center through the built-in Internet of Things card; The monitoring data processing center includes a deformation monitoring unit and a monitoring data reporting unit. The deformation monitoring unit is used to perform real-time data processing on the original observation information uploaded by the monitoring receiver, analyze and calculate the position change of the monitoring receiver, calculate the deformation degree, and send it to the server through the monitoring data reporting unit; High-definition camera device, used to check the deformation of the corresponding monitoring receiver installation point at a fixed point under the control of the server; The specific processing process of the deformation monitoring unit includes: (1) Obtain in real time the carrier phase of multiple GNSS-like signal raw observation information uploaded by a monitoring receiver at a fixed point and record it; (2) Subtract the phases of multiple carrier waves from each other and calculate the average value as a reference value to determine whether deformation occurs; The difference formula is: （1） Where, and Respectively The carrier phase of satellite n and satellite m at the epoch time, For the The carrier phase difference between satellite n and satellite m at the epoch time; According to formula (1), the reference value is: （2） Where, is the average value of the carrier phase difference between satellite n and satellite m over N epochs, which serves as a reference value; (3) Subtract the current carrier phase difference from the current reference value; The difference calculation formula is: （3） Where, is the carrier phase difference at the current epoch H, The difference between the real-time monitored carrier phase difference and the reference value; (4) When When more than half of them are greater than the monitoring threshold, it is determined that deformation has occurred and an early warning is issued; if no deformation has occurred, the current reference value and the carrier phase difference are summed and averaged as the new reference value, and then return to step (3); the calculation formula is as follows: （4）。 2. The homologous multi-channel pseudolite deformation monitoring system in a GNSS-denied environment according to claim 1, characterized in that: It also includes a solar panel, which uses solar power to power the pseudo-satellite base station module and the monitoring receiver; the infrared ranging module is powered by a battery.

3. The homologous multi-channel pseudolite deformation monitoring system in a GNSS-denied environment according to claim 1, characterized in that: The monitoring data reporting unit includes a storage module and a 4G communication module. The storage module is used to store monitoring data in real time, and the 4G communication module is used to report monitoring results in real time and issue an early warning.

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