Non-contact measurement method and system for three-dimensional deformation of slope surface based on navigation reflection signal

Abstract

The application provides a kind of slope three-dimensional deformation non-contact measurement method and system based on navigation reflection signal, belong to remote sensing technical field, including: constructing slope signal reflection model;Collect direct signal and multiple reflection signals, carry out multi-channel file reading and separation to direct signal and reflection signal, calculate the carrier phase difference of direct signal and reflection signal, carry out inversion to multiple carrier phase differences between adjacent transmission periods, obtain reflection signal multipath propagation distance variation;Reflection signal multipath propagation distance variation is substituted into slope signal reflection model to obtain reflection surface deformation variable-reflection signal propagation distance variation equation, and the reflection surface deformation variable-reflection signal propagation distance variation equation is inverted to obtain the inversion result of slope three-dimensional deformation variable.The application uses satellite navigation signal and multiple reflection antennas to calculate slope deformation variable, realizes low-cost, non-contact and high-accuracy slope three-dimensional deformation inversion process.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of remote sensing, and particularly relates to a slope three-dimensional deformation non-contact measurement method and system based on navigation reflection signals. BACKGROUND

[0002] In disaster prevention, long-time continuous monitoring of mountain slopes, and then timely early warning when landslide risks are found, is an effective method to prevent landslides and reduce property losses.

[0003] At present, the commonly used monitoring methods have some defects due to differences in signal sources and device arrangement. For example, deformation monitoring based on traditional geodetic methods involves placing multiple global navigation satellite system (GNSS) antennas on the monitoring surface, using GNSS direct signals to perform high-precision differential positioning on the antenna positions, obtaining accurate positions, and then analyzing the changes in a large number of antenna positions to achieve three-dimensional deformation monitoring. This is a traditional one-machine multi-antenna structure. However, this method requires fixing GNSS antennas on the deformation body, which is a contact measurement method. It is difficult to arrange antennas in high density on a large area of deformation body, and even impossible to arrange antennas in some dangerous places. Therefore, this method is generally suitable for key monitoring objects such as dams and bridges. Three-dimensional laser radar scanning method is a non-contact measurement method that solves the problem of difficulty in arranging antennas in traditional geodetic methods. It uses laser radar LIDAR to monitor landslide displacement, analyzes the reflected laser beam, and accurately obtains the three-dimensional data of the measured object, and then analyzes the deformation data. However, the three-dimensional laser radar has high cost, limited scanning distance and scanning range, and poor performance in cloudy and foggy weather, and cannot realize all-weather observation. Ground-based synthetic aperture radar (GB-SAR) can monitor the reflecting surface without being affected by the weather, obtain the three-dimensional deformation of the reflecting surface, and has high precision. However, it also has high cost. The use of satellite-borne SAR combined with optical effects to monitor landslides can work stably for a long time and has a large detection range. However, due to the limitation of satellite re-entry period, it is difficult to continuously monitor the deformation of fixed positions for a long time.

[0004] However, when the GNSS signal is reflected by a reflecting surface, the polarization characteristics, waveform, phase and other signal characteristics of the signal will change with the physical characteristics such as the distance of the reflecting surface. According to the direct signal and the reflected signal of GNSS, the physical information carried by the signal after being reflected by the reflecting surface can be analyzed to efficiently obtain the deformation parameters of the reflecting surface. This technology is called Global Navigation Satellite System-Reflectometry (GNSS-R). Compared with the traditional measurement method using direct signals, the GNSS-R method using reflected signals does not need to place a receiving antenna on the deformation body, avoiding the placement of the antenna and having the characteristics of non-contact measurement. There is a scheme that uses a reflecting antenna to receive GNSS-R signals reflected by a mountain slope surface at a distance of 25 meters and a mountain at a distance of nearly 100 meters, simulates a small deformation by moving the receiving antenna, and inversely calculates the deformation according to the phase difference between the direct and reflected signals. The experiment verifies that the GNSS-R signal reflected by the real slope can be used for deformation inversion, but it only obtains one-dimensional deformation facing the receiving device, and does not solve the problem of three-dimensional deformation measurement. There is another scheme that uses a reflecting antenna and multiple GNSS satellites to use data from different satellites in the reflected signal to image a target such as a building on a roof. By analyzing the position difference of the target in two imaging processes, the deformation of the target can be analyzed. However, this method uses a reflecting antenna that depends on receiving signals from multiple satellites at the same time, which requires an open terrain and is suitable for buildings on roofs, but not suitable for high-precision measurement of small displacements on inclined surfaces such as road slopes. There is another scheme that uses a reflecting antenna to receive GNSS signals reflected by a metal plate, simulates the deformation of the slope by pushing the metal plate, and obtains the deformation in the direction of the antenna after correlating the direct signal and the reflected signal, achieving a high precision of centimeters. However, this method also has the problem of short collection time, and can only analyze the one-dimensional rapid deformation process in the pushing direction.

[0005] In summary, the above methods mainly analyze the deformation of the reflecting body in the direction of the antenna using a single reflecting antenna, and can only reflect the two-dimensional deformation process. However, since the real deformation of the slope is difficult to occur only in the direction of the reflecting antenna, a new method for analyzing the deformation of the slope using a reflecting antenna needs to be proposed. SUMMARY

[0006] The present application provides a slope three-dimensional deformation non-contact measurement method and system based on navigation reflected signals, to solve the defect that the monitoring result has great limitations when a single reflecting antenna is used for slope deformation monitoring in the prior art.

[0007] In a first aspect, the present application provides a slope three-dimensional deformation non-contact measurement method based on navigation reflected signals, comprising:

[0008] According to the GNSS-R composed of a direct antenna and multiple reflection antennas, multi-path propagation is carried out on a slope surface, and a slope surface signal reflection model is constructed;

[0009] Direct signals of the direct antenna and reflection signals of the multiple reflection antennas are collected, multi-channel file reading and separation are carried out on the direct signals and the reflection signals, carrier phase differences of the direct signals and the reflection signals are calculated, multiple carrier phase differences between adjacent transmission periods are inverted, and reflection signal multi-path propagation distance variation quantities are obtained;

[0010] The reflection signal multi-path propagation distance variation quantities are substituted into the slope surface signal reflection model to obtain a reflection surface deformation variable-reflection signal propagation distance variation quantity equation, and the reflection surface deformation variable-reflection signal propagation distance variation quantity equation is inverted to obtain a slope surface three-dimensional deformation variable inversion result.

[0011] According to the slope surface three-dimensional deformation non-contact measurement method based on navigation reflection signals provided by the application, according to the GNSS-R composed of a direct antenna and multiple reflection antennas, multi-path propagation is carried out on a slope surface, and a slope surface signal reflection model is constructed, which comprises:

[0012]

[0013] Among them:

[0014]

[0015] R n represents the path propagation distance difference value of any reflection signal more than the direct signal, R T represents the part of R n before reflection on the slope surface, R R represents the part of R n after reflection on the slope surface, L n represents the projection distance of R R on the horizontal ground, ψ n represents the projection distance of R T on the horizontal ground, ψ R represents the included angle between the ground projection lines, θ and respectively, the elevation angle and the azimuth angle of the used GEO satellite are obtained by querying the experimental time satellite position, the position coordinates of the slope reflection point are R n (x, y, z), and the position coordinates of any reflection antenna are T n (x Tn ,y Tn ,h Tn ).

[0016] The application provides a slope three-dimensional deformation non-contact measurement method based on navigation reflected signals, which collects direct signals of a direct antenna and reflected signals of a plurality of reflected antennas, and comprises the following steps:

[0017] In a single preset period, the reflected signals of the plurality of reflected antennas are collected in sequence at equal time intervals;

[0018] According to a Beidou system space signal interface control file, Beidou navigation signals on any GNSS satellite are acquired:

[0019]

[0020] Wherein, j is a satellite number, A j represents a signal amplitude, C j represents a B3I signal ranging code, D j represents a data code modulated on the B3I signal ranging code, f represents a B3I signal carrier frequency, represents an initial phase, and t represents a satellite signal collection time;

[0021] Correspondingly, the direct signals received by the direct antenna Compared with has a time delay τ1 and a phase shift That is:

[0022]

[0023] The reflected signals passing through the slope Compared with has a time delay τ2 and a phase shift That is:

[0024]

[0025] The phase difference between the direct signals And the reflected signals Is:

[0026]

[0027] The application provides a slope three-dimensional deformation non-contact measurement method based on navigation reflected signals, which collects direct signals of a direct antenna and reflected signals of a plurality of reflected antennas, and comprises the following steps:

[0028] The preset sampling bit number, the preset sampling rate and the preset collection time length of the collector are determined;

[0029] ​The preset sampling bit number, the preset sampling rate and the preset collection time length are multiplied in sequence to obtain a data bit position corresponding to each reflection antenna in a reflection signal channel, and a plurality of reflection antenna data are averagely divided by searching the reflection signal channel data according to the data bit position.

[0030] The direct signal only contains direct antenna data, and the direct signal is taken as the direct antenna data.

[0031] According to the slope surface three-dimensional deformation non-contact measurement method based on navigation reflection signals, the carrier phase difference of the direct signal and the reflection signal is calculated, a plurality of carrier phase differences between adjacent transmission periods are inversed to obtain a reflection signal multi-path propagation distance variation, and the method comprises the following steps:

[0032] The direct antenna data are respectively correlated and accumulated with any reflection antenna data to obtain a correlation value result matrix, the row elements of the correlation value result matrix are reflection signal carrier phase characteristics, and the column elements are sampling point interval delays of the reflection signal relative to the direct signal.

[0033] The direct signal and any reflection signal propagation distance difference variation between adjacent two periods are determined, any carrier phase difference between the adjacent two periods is obtained from the direct signal and any reflection signal propagation distance difference variation, a collection frequency and a light speed constant.

[0034] A plurality of reflection signals in the adjacent two periods are respectively subjected to phase difference calculation to obtain a plurality of carrier phase differences.

[0035] The reflection signal multi-path propagation distance variation is obtained based on the plurality of carrier phase differences.

[0036] According to the slope surface three-dimensional deformation non-contact measurement method based on navigation reflection signals, the reflection signal multi-path propagation distance variation is substituted into the slope surface signal reflection model to obtain a reflection surface deformation variable-reflection signal propagation distance variation equation, and the method comprises the following steps:

[0037] The position coordinates of the slope reflection point in the adjacent two periods are determined by R n (x,y,z) to R n ′(x+Δx,y+Δy,z+Δz), Δx, Δy and Δz are deformation variables in three-dimensional coordinates of the adjacent two periods, and the reflection surface deformation variable is ΔR n =R n (x,y,z)-R n ′(x+Δx,y+Δy,z+Δz);

[0038] ΔR nSubstitute the slope surface signal reflection model to determine the first variation ΔR a , the second variation ΔR b and the third variation ΔR c :

[0039]

[0040] ΔR b = Δz·sin(θ);

[0041]

[0042] According to the present application, a slope surface three-dimensional deformation non-contact measurement method based on navigation reflection signals is provided, the reflection surface deformation amount-reflection signal propagation distance variation equation is inversed to obtain the slope surface three-dimensional deformation inversion result, comprising:

[0043] determining the actual slope surface reflection point vector and the estimated slope surface reflection point vector M n (x, y, z) pair is Taylor expanded at to obtain:

[0044]

[0045] wherein, is the Hessian matrix;

[0046] determining the deformed is then

[0047] wherein x0, y0 and z0 are low-order terms, and are Taylor expansion coefficients of each low-order term, respectively;

[0048]

[0049] substitute ΔR n into the multi-antenna reflection equation group composed of multiple reflection antennas, wherein:

[0050]

[0051] the least square method is used to solve the optimal solution of Δx, Δy and Δz, and the optimal solution is taken as the obtained slope surface three-dimensional deformation inversion result.

[0052] In a second aspect, the present application further provides a non-contact measurement system for three-dimensional deformation of a slope surface based on navigation reflection signals, comprising:

[0053] a construction module for constructing a signal reflection model of the slope surface based on GNSS-R of the direct antenna and the plurality of reflection antennas for multipath propagation on the slope surface;

[0054] a calculation module for collecting direct signals of the direct antenna and reflection signals of the plurality of reflection antennas, performing multi-channel file reading and separation on the direct signals and the reflection signals, calculating carrier phase differences of the direct signals and the reflection signals, and inverting a plurality of carrier phase differences between adjacent transmission periods to obtain a reflection signal multipath propagation distance variation;

[0055] an inversion module for substituting the reflection signal multipath propagation distance variation into the signal reflection model of the slope surface to obtain a reflection surface deformation variable-reflection signal propagation distance variation equation, and inverting the reflection surface deformation variable-reflection signal propagation distance variation equation to obtain an inversion result of the three-dimensional deformation variable of the slope surface.

[0056] In a third aspect, the present application further provides an electronic device comprising a memory, a processor, and a computer program stored on the memory and executable on the processor, wherein the processor executes the program to implement the non-contact measurement method for three-dimensional deformation of a slope surface based on navigation reflection signals.

[0057] In a fourth aspect, the present application further provides a non-transitory computer readable storage medium having a computer program stored thereon, wherein the computer program is executable by a processor to implement the non-contact measurement method for three-dimensional deformation of a slope surface based on navigation reflection signals.

[0058] The non-contact measurement method for three-dimensional deformation of a slope surface based on navigation reflection signals provided by the present application calculates the deformation variable of the slope surface by using satellite navigation signals and a plurality of reflection antennas, and realizes a low-cost, non-contact, and high-accuracy inversion process for three-dimensional deformation of the slope surface. BRIEF DESCRIPTION OF DRAWINGS

[0059] In order to more clearly illustrate the technical solutions in the present application or prior art, the following will briefly introduce the drawings needed to be used in the embodiments or prior art description. Obviously, the drawings in the following description are some embodiments of the present application, and for those skilled in the art, other drawings can also be obtained without creative labor.

[0060] Figure 1 is one of the flowcharts of the non-contact measurement method for three-dimensional deformation of a slope surface based on navigation reflection signals provided by the present application;

[0061] Figure 2 is an antenna arrangement provided by the present application;

[0062] Figure 3 is a flowchart of a method for non-contact measurement of three-dimensional deformation of a slope surface based on navigation reflected signals provided by the present application;

[0063] Figure 4 is a signal reflection model provided by the present application;

[0064] Figure 5 is a correlation value matrix result provided by the present application;

[0065] Figure 6 is a structural schematic diagram of a system for non-contact measurement of three-dimensional deformation of a slope surface based on navigation reflected signals provided by the present application;

[0066] Figure 7 is a structural schematic diagram of an electronic device provided by the present application. DETAILED DESCRIPTION

[0067] In order to make the objects, technical solutions and advantages of the present application clearer, the technical solutions in the present application will be described clearly and completely below with reference to the drawings in the present application. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor fall within the scope of protection of the present application.

[0068] Figure 1 is a flowchart of a method for non-contact measurement of three-dimensional deformation of a slope surface based on navigation reflected signals provided by the present application, as shown in Figure 1 , comprising:

[0069] Step 100: constructing a signal reflection model of a slope surface according to GNSS-R composed of a direct antenna and a plurality of reflection antennas for multipath propagation on the slope surface;

[0070] Step 200: collecting direct signals of the direct antenna and reflection signals of the plurality of reflection antennas, performing multi-channel file reading and separation on the direct signals and the reflection signals, calculating carrier phase differences of the direct signals and the reflection signals, inverting a plurality of carrier phase differences between adjacent transmission periods to obtain reflection signal multipath propagation distance variation;

[0071] Step 300: substituting the reflection signal multipath propagation distance variation into the signal reflection model of the slope surface to obtain a reflection surface deformation variable-reflection signal propagation distance variation equation, inverting the reflection surface deformation variable-reflection signal propagation distance variation equation to obtain an inversion result of three-dimensional deformation of the slope surface.

[0072] The embodiment of the present application provides a non-contact three-dimensional deformation measurement system of a slope surface based on navigation reflection signals, which comprises a direct antenna, a reflection antenna 1, a reflection antenna 2, a reflection antenna 3, a reflection antenna 4, a Beidou navigation signal collector and a data processing computer, as shown in the figure. Figure 2 Figure 2 In the figure, S is a Beidou GEO satellite, H is a deformation slope surface, D is a direct antenna, C is a Beidou navigation signal collector, T1, T2, T3 and T4 are four reflection antennas, 1, 2, 3 and 4 are GNSS-R signals reflected by H, and 5 is a direct GNSS signal. The direct antenna is a right-handed polarization antenna, which is arranged in front of the slope surface and faces away from the slope surface, and the beam is directed to the Beidou GEO satellite to directly receive the GNSS signal transmitted by the Beidou GEO satellite. The reflection antennas 1, 2, 3 and 4 are all left-handed polarization antennas, which are arranged with the beam towards the slope surface to receive the Beidou GNSS signal reflected by the slope surface. The four reflection antennas are different in position and point to a reflection point of the slope surface from different azimuth angles to receive the Beidou GNSS-R signals reflected by the slope surface in different directions. The four reflection antennas are different in height and point to a reflection point of the slope surface from different elevation angles to receive the Beidou GNSS-R signals reflected by the slope surface in different heights. The Beidou navigation signal collector comprises a double-channel GNSS signal collector with two channels of direct and reflection and an antenna switch with four input ports and one output port. The double-channel GNSS signal collector collects the GNSS signals of the two channels through the built-in GNSS signal sampling chip and stores them as binary raw files. The direct channel of the collector is always connected with the direct antenna through a coaxial cable. The reflection channel of the collector is connected with the output port of the antenna switch through a coaxial cable, the four input ports of the antenna switch are connected with the four reflection antennas through coaxial cables, and the switch sequentially connects one of the four reflection antennas to the reflection channel at certain time intervals. The data processing computer processes the binary raw files through data separation, carrier phase extraction and deformation inversion, and completes the non-contact measurement of the three-dimensional deformation of the slope surface.

[0073] As shown in the figure, Figure 3 Figure 3 ​​Period 1 is a cycle 1, indicating that the steps in the dashed box 1 are performed on the signals in the cycle 1. Period 2 is a cycle 2, indicating that the steps in the dashed box 2 are performed on the signals in the cycle 2; 3 is direct and reflected antenna data acquisition; 4 is file reading and separation; 5 is direct and reflected signal carrier phase difference extraction; 6 is the change amount of the reflection signal propagation distance between the cycles; 7 is the construction of the slope signal reflection model; 8 is the establishment of the reflection surface deformation variable-reflection signal propagation distance change equation; 9 is the slope three-dimensional deformation variable inversion. The Beidou navigation signal collector collects direct and reflected GNSS signals and transmits them to the data processing computer. The data processing computer processes the GNSS-R signal of each reflection antenna and the direct GNSS signal in the same cycle, and extracts the direct and reflected signal carrier phase difference. In the second acquisition cycle, the same method is used to extract the carrier phase difference of the direct and reflected signals in another cycle, and the change amount of the carrier phase difference of the two cycles is obtained, and then the multi-path propagation distance change amount of the reflection signal between the two cycles is inverted. The multi-path propagation distance change amount of the four-way reflection GNSS-R signal is substituted into the four sets of reflection surface deformation variable-reflection signal distance change equation, and the slope three-dimensional deformation variable between the two cycles is solved by using the least square method.

[0074] The present application calculates the slope deformation variable by using satellite navigation signals and multiple reflection antennas, and realizes a low-cost, non-contact and high-accuracy slope three-dimensional deformation inversion process.

[0075] On the basis of the above embodiment, the GNSS-R composed of a direct antenna and multiple reflection antennas performs multi-path propagation on the slope, and a slope signal reflection model is constructed, including:

[0076] For the reflection antenna T n The GNSS signal reflection model is established as shown in Figure 4 , wherein the path propagation distance difference value of the reflection signal received by the antenna is more than the direct signal R n =R T +R R . The position T n (x Tn ,y Tn ,h Tn ) of the reflection antenna can be obtained by measurement, wherein h Tn is the height of the reflection antenna. The elevation angle of the used GEO satellite is θ and the azimuth angle is Suppose the position of the reflection point is R n (x,y,z), then they satisfy the following equation:

[0077]

[0078] Among them:

[0079]

[0080] R n represents the path propagation distance difference of any reflected signal more than direct signal, R T represents the R n part before the slope reflection in R R represents the R n part after the slope reflection in R n represents the R R projected distance on the horizontal ground, ψ n represents the R T and R R the included angle between the ground projection lines, θ and respectively, the elevation and azimuth of the used GEO satellite obtained by querying the experimental time satellite position, the position coordinates of the slope reflection point are R n (x, y, z), the position coordinates of any reflected antenna are T n (x Tn , y Tn , h Tn ).

[0081] On the basis of the above embodiment, the direct signal of the direct antenna and the reflected signal of the plurality of reflected antennas are collected, comprising:

[0082] By collecting GNSS signals from the direct antenna and GNSS-R signals from the four reflected antennas for a long time, and storing them as binary raw files.

[0083] As Figure 2 shown, a direct antenna D and four reflected antennas T1, T2, T3, T4 are arranged in front of the reflection slope H, and are connected with the Beidou navigation signal collector C in the aforementioned manner. The direct antenna D points to the south sky and continuously receives Beidou GEO satellite signals. For example, the azimuth of Beidou GEO01 is 131° and the elevation is 42°, so the direct antenna D points to this position. The direct antenna signal is directly collected by the collector direct channel. The reflected antennas T1, T2, T3, T4 are directed to the reflection slope. When the Beidou navigation signal irradiates to the target slope, scattering will occur in all directions, and T1, T2, T3, T4 respectively receive the Beidou GNSS-R signals scattered in different directions by the slope reflection point from four different positions and heights.

[0084] In a single preset period, the reflected signals of the plurality of reflected antennas are sequentially collected at equal time intervals;

[0085] For example, in a period of 1 hour, under the action of a multi-channel switcher: 0-15 minutes T1 is connected with the reflector channel of the collector, the collector collects GNSS-R signals received by T1; 15-30 minutes T2 is connected with the reflector channel of the collector, the collector collects GNSS-R signals received by T2; 30-45 minutes T3 is connected with the reflector channel of the collector, the collector collects GNSS-R signals received by T3; 45-60 minutes T4 is connected with the reflector channel of the collector, the collector collects GNSS-R signals received by T4, and the process is repeated in the next period. The collector is kept powered on during the collection process to prevent phase jumps caused by collector initialization.

[0086] According to the Beidou system space signal interface control document (ICD) file, the Beidou navigation signal on any GNSS satellite is obtained:

[0087]

[0088] Wherein, j is the satellite number, A j represents the signal amplitude, C j represents the B3I signal ranging code, D j represents the data code modulated on the B3I signal ranging code, f represents the B3I signal carrier frequency, represents the initial phase, t represents the satellite signal collection time;

[0089] Correspondingly, the direct signal received by the direct antenna has a time delay τ1 and a phase shift Compared with That is:

[0090]

[0091] The reflected signal passing through the slope has a time delay τ2 and a phase shift Compared with That is:

[0092]

[0093] The direct signal and the reflected signal The phase difference between is:

[0094]

[0095] On the basis of the above embodiment, the direct signal and the reflected signal are subjected to multi-channel file reading and separation, comprising:

[0096] The preset sampling bit number, the preset sampling rate and the preset collection time of the collector are determined;

[0097] The preset sampling bit number, the preset sampling rate and the preset collection time length are multiplied in sequence to obtain a data bit position corresponding to each reflection antenna in the reflection signal channel, and a plurality of reflection antenna data are divided by searching the reflection signal channel data according to the data bit position.

[0098] The direct signal only contains one direct antenna data, and the direct signal is taken as the direct antenna data.

[0099] Specifically, after the collection is completed, the data of the direct channel and the reflection channel are transmitted to a data processing computer through a USB port. By using a program, the data is decoded according to a data coding format, and the channel data is separated. For example:

[0100] When the collector sampling bit number is 2bit and the sampling rate is 16.369MHz, if the collection time is t minutes, then the direct channel and the reflection channel data each have 60*t*16.396M*2 / 8 bytes. Since the direct signal only contains one direct antenna data, it is not necessary to separate the direct channel data S d which is the GNSS data of the direct antenna D.

[0101] The 15*4n*16.396M*2 / 8 to 15*(4n+1)*16.396M*2 / 8-1 bytes of the reflection channel data are reflection antenna T1 data S1.

[0102] The 15*(4n+1)*16.396M*2 / 8 to 15*(4n+2)*16.396M*2 / 8-1 bytes are reflection antenna T2 data S2.

[0103] The 15*(4n+2)*16.396M*2 / 8 to 15*(4n+3)*16.396M*2 / 8-1 bytes are reflection antenna T3 data S3.

[0104] The 15*(4n+3)*16.396M*2 / 8 to 15*(4n+4)*16.396M*2 / 8-1 bytes are reflection antenna T4 data S4, wherein n=0, 1, 2, ….

[0105] On the basis of the above embodiment, the carrier phase difference between the direct signal and the reflection signal is calculated, a plurality of carrier phase differences between adjacent transmission periods are inversed to obtain a reflection signal multipath propagation distance change amount, including:

[0106] Correlate the direct antenna data with any reflected antenna data respectively to obtain a correlation value result matrix, the row elements of the correlation value result matrix being reflected signal carrier phase characteristics, and the column elements being sampling point interval delays of the reflected signal relative to the direct signal;

[0107] Determine a direct signal and any reflected signal propagation distance difference change quantity between adjacent two periods, and obtain any carrier phase difference between the adjacent two periods from the direct signal and any reflected signal propagation distance difference change quantity, a collection frequency, and a light speed constant;

[0108] Respectively perform phase difference calculation on the multiple reflected signals in the adjacent two periods to obtain multiple carrier phase differences;

[0109] Obtain the reflected signal multipath propagation distance change quantity based on the multiple carrier phase differences.

[0110] Specifically, the embodiment of the present application is aimed at the reflected antenna GNSS-R data S1, S2, S3, S4 and the direct signal S d After correlation accumulation, carrier phase difference extraction and propagation distance difference inversion processes are performed on the correlation value results.

[0111] The direct signal S d is correlated with the reflected signal S n to obtain an N-row-by-T-column correlation value result matrix as shown in the following table: Figure 5 The correlation value in the tth column indicates that the reflected signal is delayed by t sampling point intervals relative to the direct signal. Under the aforementioned sampling frequency, the signal multipath propagation distance corresponding to one sampling point interval delay of the reflected signal is about 4 meters, so the sampling point interval is also called distance cell resolution. The n rows of correlation values in the tth column reflect the carrier phase characteristics of the reflected signal in the tth sampling point interval. The color in the result indicates the magnitude of the correlation value amplitude, and the distance cell with high amplitude indicates that the reflected signal at the distance cell is strong, because there is a reflecting surface, so the reflected signal at the distance cell is 30 dB higher than that at other distance cells. In the result shown in the following table, the maximum correlation value amplitude appears in the 4th distance cell, and the distance between the target reflecting surface and the reflected antenna is about 16 meters, that is, it is determined that the data at the distance cell comes from the GNSS-R signal of the target reflecting surface selected in the experiment. Figure 5

[0112] Because the obtained correlation value is a complex number, the amplitude angle thereof is the carrier phase difference between the direct signal and the reflected signal in the pseudo-code period For each GNSS antenna, the change quantity AR of the direct signal and the reflected signal propagation distance difference R between period 1 and period 2 and the change quantity of the signal carrier phase difference between the two periods There is the following relationship: ​

[0113]

[0114] Where f is the sampling frequency and c is the speed of light constant.

[0115] The above processing is performed on the GNSS-R data S1, S2, S3, and S4 of the reflecting antenna for periods 1 and 2, respectively, according to... The changes in multipath propagation distance of the reflected GNSS-R signal received by each reflecting antenna during the interval from period 1 to period 2 are obtained as ΔR1, ΔR2, ΔR3, and ΔR4.

[0116] Based on the above embodiments, and according to the slope signal reflection model, an equation is constructed to represent the change in reflection surface deformation versus the change in reflection signal distance when the slope deforms. Substituting the obtained changes in the multipath propagation distance of the reflection signal ΔR1, ΔR2, ΔR3, and ΔR4 into the equation, the positional change of the reflecting slope within that period is obtained.

[0117] When the slope deforms between period 1 and period 2, the position of the reflection point changes to R within period 2. n (x+Δx,y+Δy,z+Δz). This causes a change ΔR in the multipath propagation distance R of the signal. n =R n (x,y,z)-R n ′(x+Δx,y+Δy,z+Δz).

[0118] Let ΔR n L n cos(θ)cos(ψ n The change in the term is ΔR a 、|h Tn The change in the term -z|sin(θ) is The change in the term is ΔR c The following steps will solve each problem individually:

[0119] 1) For ΔR a :

[0120] Let γ = actg((yy) Tn ) / (xx Tn )),but

[0121] Simplify to get but

[0122] 2) For ΔR b :

[0123] In actual measurement, the antenna height h TnBelow the reflection point position z, so |h Tn -z = z - h Tn ,

[0124] So ΔR b = Δz·sin(θ).

[0125] 3) For ΔR c :

[0126] Let R n the third term is

[0127]

[0128] Let the unknown actual reflection point (x, y, z) be vector The known estimated reflection point (x0, y0, z0) is vector

[0129] To solve After a small deformation near The expression after deformation, formula M n to At Taylor expansion:

[0130]

[0131] Where is the second-order derivative matrix, i.e. Hessian matrix:

[0132]

[0133] After deformation The corresponding change is

[0134] After subtracting the two formulas and ignoring high-order terms, we get:

[0135]

[0136] So:

[0137]

[0138] Where x0, y0, and z0 are low-order terms, and are the Taylor expansion coefficients of each low-order term, respectively.

[0139] Using the data of T1, T2, T3, and T4 four reflector antennas, we can form the following equation group.

[0140] ​

[0141] Wherein:

[0142]

[0143] In the embodiment of the present application, n takes 1, 2, 3 and 4, the above formula is an equation group containing only three variables (Δx, Δy, Δz) of unknown quantity, and the optimal solution of the reflection point deformation variables Δx, Δy, Δz in the least square sense can be obtained by using the least square method.

[0144] Let Q (Δx, Δy, Δz) = [d1-(a1Δx+b1Δy+c1Δz)] 2 +[d2-(a2Δx+b2Δy+c2Δz)] 2 +[d3-(a3Δx+b3Δy+c3Δz)] 2 +[d4-(a4Δx+b4Δy+c4Δz)] 2 Then (Δx, Δy, Δz) when Q takes the minimum value is the optimal solution. Therefore, we have:

[0145]

[0146] Solving the above equation group obtains (Δx, Δy, Δz) which is the optimal solution in the least square sense, as the slope surface three-dimensional deformation inversion result, the above process is a measurement process of once slope surface three-dimensional deformation.

[0147] The navigation reflection signal-based slope surface three-dimensional deformation non-contact measurement system provided by the present application is described below, and the navigation reflection signal-based slope surface three-dimensional deformation non-contact measurement system described below can be correspondingly referred to the navigation reflection signal-based slope surface three-dimensional deformation non-contact measurement method described above.

[0148] Figure 6 The navigation reflection signal-based slope surface three-dimensional deformation non-contact measurement system provided by the present application is described below, and the navigation reflection signal-based slope surface three-dimensional deformation non-contact measurement system described below can be correspondingly referred to the navigation reflection signal-based slope surface three-dimensional deformation non-contact measurement method described above. Figure 6 As shown in FIG. 1, the navigation reflection signal-based slope surface three-dimensional deformation non-contact measurement system comprises a construction module 61, a calculation module 62 and an inversion module 63, wherein:

[0149] The construction module 61 is used to construct a slope signal reflection model based on the multipath propagation of GNSS-R composed of a direct antenna and multiple reflective antennas on a slope. The calculation module 62 is used to collect the direct signal from the direct antenna and the reflected signal from the multiple reflective antennas, perform multi-channel file reading and separation on the direct signal and the reflected signal, calculate the carrier phase difference between the direct signal and the reflected signal, and invert the multiple carrier phase differences between adjacent transmission cycles to obtain the change in the multipath propagation distance of the reflected signal. The inversion module 63 is used to substitute the change in the multipath propagation distance of the reflected signal into the slope signal reflection model to obtain the equation of reflection surface deformation - change in reflection signal propagation distance, and invert the equation of reflection surface deformation - change in reflection signal propagation distance to obtain the slope three-dimensional deformation inversion result.

[0150] Figure 7 An example is a schematic diagram of the physical structure of an electronic device, such as... Figure 7 As shown, the electronic device may include: a processor 710, a communication interface 720, a memory 730, and a communication bus 740, wherein the processor 710, the communication interface 720, and the memory 730 communicate with each other through the communication bus 740. The processor 710 can call logic instructions in the memory 730 to execute a non-contact measurement method for three-dimensional deformation of a slope based on navigation reflection signals. This method includes: constructing a slope signal reflection model based on multipath propagation of a GNSS-R consisting of a direct antenna and multiple reflecting antennas on the slope; acquiring the direct signal from the direct antenna and the reflected signals from the multiple reflecting antennas; performing multi-channel file reading and separation on the direct signal and the reflected signal; calculating the carrier phase difference between the direct signal and the reflected signal; inverting multiple carrier phase differences between adjacent transmission cycles to obtain the change in multipath propagation distance of the reflected signal; substituting the change in multipath propagation distance of the reflected signal into the slope signal reflection model to obtain the equation for the change in reflection surface deformation - the change in reflection signal propagation distance; and inverting the equation for the change in reflection surface deformation - the change in reflection signal propagation distance to obtain the slope three-dimensional deformation inversion result.

[0151] In addition, the logic instructions in the memory 730 described above can be implemented in the form of software functional units and sold or used as independent products, and can be stored in a computer readable storage medium. Based on such understanding, the technical solutions of the present application essentially or the part that contributes to the prior art or part of the technical solutions can be embodied in the form of a software product, and the computer software product is stored in a storage medium, including a plurality of instructions to make a computer device (which can be a personal computer, a server, or a network device, etc.) execute all or part of the steps of the method described in various embodiments of the present application. The foregoing storage medium includes: a U disk, a mobile hard disk, a read-only memory (ROM, Read-Only Memory), a random access memory (RAM, Random Access Memory), a magnetic disk or an optical disk, and various media that can store program codes.

[0152] In another aspect, the present application also provides a computer program product, which comprises a computer program, the computer program can be stored on a non-transitory computer readable storage medium, and the computer program can be executed by a processor, so that the computer can execute the navigation reflection signal based slope three-dimensional deformation non-contact measurement method provided by the above method, the method comprises the following steps: constructing a slope signal reflection model according to the multipath propagation of GNSS-R composed of a direct antenna and a plurality of reflection antennas on a slope; collecting direct signals of the direct antenna and reflection signals of the plurality of reflection antennas, performing multi-channel file reading and separation on the direct signals and the reflection signals, calculating the carrier phase difference of the direct signals and the reflection signals, inverting a plurality of carrier phase differences between adjacent transmission periods to obtain reflection signal multipath propagation distance variation; substituting the reflection signal multipath propagation distance variation into the slope signal reflection model to obtain a reflection surface deformation variable-reflection signal propagation distance variation equation, and inverting the reflection surface deformation variable-reflection signal propagation distance variation equation to obtain a slope three-dimensional deformation variable inversion result.

[0153] In yet another aspect, the present application also provides a non-transitory computer readable storage medium having stored thereon a computer program, which, when executed by a processor, implements the method for non-contact measurement of three-dimensional deformation of a slope surface based on navigation reflected signals as provided above, which comprises: constructing a signal reflection model of a slope surface according to GNSS-R of a direct antenna and a plurality of reflection antennas for multipath propagation on the slope surface; collecting direct signals of the direct antenna and reflection signals of the plurality of reflection antennas, performing multi-channel file reading and separation on the direct signals and the reflection signals, calculating carrier phase differences of the direct signals and the reflection signals, inverting a plurality of carrier phase differences between adjacent transmission periods to obtain a reflection signal multipath propagation distance variation; substituting the reflection signal multipath propagation distance variation into the signal reflection model of the slope surface to obtain a reflection surface deformation variable-reflection signal propagation distance variation equation, and inverting the reflection surface deformation variable-reflection signal propagation distance variation equation to obtain an inversion result of three-dimensional deformation variables of the slope surface.

[0154] The device embodiments described above are merely illustrative, wherein the units described as separate components can or can not be physically separate, and the components shown as units can or can not be physical units, i.e., can be located in one place or distributed on multiple network units. Part or all of the modules can be selected to achieve the purpose of the embodiment scheme according to actual needs. Those skilled in the art can understand and implement without creative labor.

[0155] From the above description of the embodiments, those skilled in the art can clearly understand that the embodiments can be realized by means of software and necessary universal hardware platforms, and of course can also be realized by hardware. Based on such understanding, the above technical solutions can be embodied in the form of a software product, which can be stored in a computer readable storage medium, such as ROM / RAM, magnetic disk, optical disk, etc., and includes a plurality of instructions for causing a computer device (which can be a personal computer, a server, or a network device, etc.) to execute the methods described in each embodiment or some parts of the embodiments.

[0156] Finally, it should be noted that: the above embodiments are only used to illustrate the technical solutions of the present application, and not to limit them; although the present application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that: it can still modify the technical solutions recorded in the foregoing embodiments, or make equivalent replacement for some technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the embodiments of the present application.

Claims

1. A non-contact measurement method for three-dimensional deformation of slope based on navigation reflection signals, characterized in that, include: Based on the multipath propagation of the Global Navigation Satellite System Reflectometer (GNSS-R), which consists of a direct antenna and multiple reflective antennas, on a slope, a slope signal reflection model is constructed. The system collects the direct signal from the direct antenna and the reflected signals from the multiple reflecting antennas, performs multi-channel file reading and separation on the direct signal and the reflected signal, calculates the carrier phase difference between the direct signal and the reflected signal, and inverts the multiple carrier phase differences between adjacent transmission cycles to obtain the change in the multipath propagation distance of the reflected signal. Substituting the change in the multipath propagation distance of the reflected signal into the slope signal reflection model, we obtain the equation of the change in the reflection surface deformation - the change in the propagation distance of the reflected signal. We then perform an inversion on the equation of the change in the reflection surface deformation - the change in the propagation distance of the reflected signal to obtain the inversion result of the three-dimensional deformation of the slope. Based on the multipath propagation of GNSS-R consisting of a direct antenna and multiple reflecting antennas on a slope, a slope signal reflection model is constructed, including: in: This represents the difference in path propagation distance between any reflected signal and the direct signal. express The part before reflection from the slope surface, express The portion after reflection from the slope surface express Projected distance on a horizontal surface express and The angle between the ground projection lines, and The elevation and azimuth angles of the GEO satellite used were obtained by querying the satellite position at the experimental time, and the coordinates of the slope reflection point were as follows: The position coordinates of any reflecting antenna are ; Substituting the change in the multipath propagation distance of the reflected signal into the slope signal reflection model yields the equation for the change in the reflection surface deformation versus the change in the propagation distance of the reflected signal, including: The coordinates of the slope reflection point within two adjacent cycles are determined by... Become , These represent the deformations of two adjacent periods in three-dimensional coordinates, with the deformation of the reflecting surface being... ; Will Substitute the values ​​into the slope signal reflection model to determine the first change. Second change and the third change : ； ； ； The equation for the change in reflection surface deformation versus the change in reflection signal propagation distance is inverted to obtain the three-dimensional deformation inversion results of the slope, including: Determine the actual reflection point vector on the slope. and slope surface predicted reflection point vector ,Will right exist Taylor expansion yields: ,in, It is the Hessian matrix; Determine the deformation after for ,but = = ,in It is a lower-order term. These are the Taylor expansion coefficients of each lower-order term. ; Will Substituting multiple reflecting antennas into a system of multi-antenna reflection equations, where: Solve using the least squares method The optimal solution is obtained and used as the inversion result of the three-dimensional deformation of the slope.

2. The non-contact measurement method for three-dimensional deformation of slope based on navigation reflection signals according to claim 1, characterized in that, Acquiring the direct signal from the direct antenna and the reflected signals from the plurality of reflecting antennas, including: Within a single preset period, the reflected signals of the plurality of reflective antennas are collected sequentially at equal time intervals; According to the BeiDou system space signal interface control file, obtain the BeiDou navigation signal from any GNSS satellite: in, Number the satellite. Indicates signal amplitude. This represents the B3I signal ranging code. This represents the data code modulated on the B3I signal ranging code. This indicates the carrier frequency of the B3I signal. Indicates the initial phase. Indicates the time of satellite signal acquisition; Correspondingly, the direct signal received by the direct antenna ,and Compared to those with latency and phase shift ,Right now: The reflected signal after passing through the slope , and Compared to those with latency and phase shift ， Right now: The direct signal With the reflected signal phase difference for: 。 3. The non-contact measurement method for three-dimensional deformation of slope based on navigation reflection signals according to claim 1, characterized in that, Multi-channel file reading and separation of the direct signal and the reflected signal includes: Determine the preset sampling bit depth, preset sampling rate, and preset sampling duration of the data acquisition device; The preset sampling bit depth, the preset sampling rate, and the preset acquisition duration are multiplied sequentially to obtain the data bit position corresponding to each reflective antenna in the reflected signal channel. The data bit position is then searched in the reflected signal channel data to divide the data of multiple reflective antennas on an average basis. The direct signal contains only one direct antenna data, and the direct signal is used as the direct antenna data.

4. The non-contact measurement method for three-dimensional deformation of slope based on navigation reflection signals according to claim 3, characterized in that, Calculate the carrier phase difference between the direct signal and the reflected signal, invert multiple carrier phase differences between adjacent transmission cycles, and obtain the multipath propagation distance variation of the reflected signal, including: The data from the direct antenna is correlated and accumulated with the data from any reflective antenna to obtain a correlation result matrix. The row elements of the correlation result matrix are the carrier phase characteristics of the reflected signal, and the column elements are the sampling point interval delay of the reflected signal relative to the direct signal. Determine the change in the propagation distance difference between the direct signal and any reflected signal between two adjacent cycles. Using the change in the propagation distance difference between the direct signal and any reflected signal, the acquisition frequency, and the constant speed of light, obtain the phase difference of any carrier between the two adjacent cycles. The phase difference of multiple reflected signals within two adjacent periods is calculated to obtain multiple carrier phase differences; Based on the multiple carrier phase differences, the change in the multipath propagation distance of the reflected signal is obtained.

5. A non-contact measurement system for three-dimensional slope deformation based on navigation reflection signals, based on the non-contact measurement method for three-dimensional slope deformation based on navigation reflection signals according to any one of claims 1 to 4, characterized in that, include: The module is used to construct a slope signal reflection model based on the multipath propagation of GNSS-R composed of a direct antenna and multiple reflective antennas on a slope. The calculation module is used to collect the direct signal from the direct antenna and the reflected signals from the multiple reflecting antennas, perform multi-channel file reading and separation on the direct signal and the reflected signal, calculate the carrier phase difference between the direct signal and the reflected signal, and invert the multiple carrier phase differences between adjacent transmission cycles to obtain the change in the multipath propagation distance of the reflected signal. The inversion module is used to substitute the change in the multipath propagation distance of the reflected signal into the slope signal reflection model to obtain the equation of the change in the reflection surface deformation - the change in the propagation distance of the reflected signal, and to invert the equation of the change in the reflection surface deformation - the change in the propagation distance of the reflected signal to obtain the inversion result of the three-dimensional deformation of the slope.

6. An electronic device comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, characterized in that, When the processor executes the program, it implements the non-contact measurement method for three-dimensional deformation of slope based on navigation reflection signals as described in any one of claims 1 to 4.

7. A non-transitory computer-readable storage medium having a computer program stored thereon, characterized in that, When the computer program is executed by the processor, it implements the non-contact measurement method for three-dimensional deformation of slope based on navigation reflection signals as described in any one of claims 1 to 4.

Images