CN221261244U - Device for measuring surface deformation - Google Patents

Abstract

The utility model belongs to the technical field of surface measurement, and particularly relates to a device for surface deformation measurement. The device for measuring the deformation of the ground surface comprises a plurality of bases, wherein the bases are fixedly connected with the ground; the universal GNSS receiver is fixedly arranged on the base; the angle reflector is arranged on the base through a plurality of telescopic rods, and the angle of the reflecting surface of the angle reflector can be adjusted by adjusting the positions of the telescopic rods and the base and the telescopic length of the telescopic rods. The method can overcome the influence of space-time decoherence on the interferometry technology of the synthetic aperture radar.

Description

Device for measuring surface deformation

Technical Field

The utility model belongs to the technical field of surface measurement, and particularly relates to a device for surface deformation measurement.

Background

The surface deformation is mainly represented by earthquake deformation, ground subsidence (groundwater/oil gas exploitation, mining subsidence, and the like), landslide, glacier flow, volcanic uplift or subsidence, crust fault movement, and the like. These surface deformation phenomena are closely related to human activities, and it is important to grasp these surface deformation information.

The synthetic aperture radar interferometry-InSAR (Synthetic Aperture Radar Interferometry) technology is gradually mature and is applied in engineering, has become a main technical means for monitoring the surface deformation, and is widely applied to global and regional landform mapping and large-scale surface deformation monitoring, such as surface deformation monitoring before and after an earthquake, urban ground subsidence caused by factors such as over-mining of underground water, influence of railway/high-speed rail/subway construction projects on the surface along the line, glacier movement monitoring, mining area collapse monitoring and the like.

The InSAR technology utilizes a radar system to acquire phase information provided by two SAR images in the same region for interference processing to acquire three-dimensional information of the earth surface, and can establish a digital elevation model of a target region. For example, the SRTM project in the united states is to acquire medium resolution DEM data of 80% of the global land coverage using the InSAR technology; the TanDEM-X satellite program in Germany acquires global high resolution DEM data.

In practical applications, synthetic aperture radar interferometry (InSAR) techniques are subject to spatio-temporal decoherence.

Disclosure of utility model

In view of the above technical problems, the present utility model aims to propose a device for surface deformation measurement, which can overcome the influence of space-time decoherence on synthetic aperture radar interferometry (InSAR) technology.

According to the present utility model there is provided an apparatus for surface deformation measurement comprising:

the bases are fixedly connected with the ground;

The universal GNSS receiver is fixedly arranged on the base;

The angle reflector is arranged on the base through a plurality of telescopic rods, and the angle of the reflecting surface of the angle reflector can be adjusted by adjusting the positions of the telescopic rods and the base and the telescopic length of the telescopic rods.

In a preferred embodiment, the corner reflector is arranged as a triangle, one of the faces of the corner reflector being a reflecting face.

In a preferred embodiment, the corner reflector comprises three congruent isosceles right triangular plates and one equilateral triangular plate, which is the reflecting surface of the corner reflector.

In a preferred embodiment, the number of telescopic rods is three.

In a preferred embodiment, three said telescopic rods are hinged to adjacent sides of three isosceles right triangle plates, respectively.

In a preferred embodiment, the telescopic rod comprises a fixed rod fixedly connected with the base and a sliding rod hinged with the corner reflector, and the sliding rod is sleeved on the fixed rod in a sliding mode.

In a preferred embodiment, at least one radially sliding pin is provided on the sliding rod, and a plurality of insertion holes are axially provided on the fixing rod, and the pin can be inserted into the insertion holes, so that the sliding rod is fixed relative to the fixing rod.

In a preferred embodiment, the universal GNSS receiver is fixedly connected to the base by means of a viewing rod.

In a preferred embodiment, the elevation of the generic GNSS receiver is higher than the elevation of the corner reflector.

In a preferred embodiment, a bayonet is provided on the base, the lower end of the telescopic rod being shaped to match the bayonet.

Compared with the prior art, the application has the following advantages.

The utility model combines the GNSS technology and the time sequence InSAR technology, realizes various error corrections and CR point precision verification in deformation monitoring, and obviously improves the precision of the observation result of the time sequence InSAR technology in the installation area.

The angle, the direction and the height of the corner reflector are convenient to adjust, and the corner reflector is convenient to receive SAR satellite signals with different incident angles and different orbits. The structure design is simple, the installation is simple and convenient and quick, and the time and labor cost in the field installation process of the corner reflector is greatly saved.

Drawings

The present utility model will be described below with reference to the accompanying drawings.

FIG. 1 shows a schematic view of one embodiment of an apparatus for surface deformation measurement according to the present utility model;

Fig. 2 shows a schematic shape and structure of an embodiment of a corner reflector according to the present utility model;

Fig. 3 shows a schematic view of an embodiment of a bayonet according to the utility model;

FIG. 4 shows a schematic view of an AOD cross section of a corner reflector according to the utility model;

FIG. 5 shows a relationship between the CB side of the corner reflector and the heading of the satellite in the ascending orbit mode, wherein the vertical line in the figure is in the true north direction, and the solid line with an arrow is the heading of the satellite;

fig. 6 shows a relationship diagram of CB side of the corner reflector according to the present utility model and a satellite heading in a down-track mode, wherein a vertical line in the diagram is true north direction, and a solid line with an arrow is the satellite heading.

In the figure: 1. a base; 11. a bayonet; 2. a pervasive GNSS receiver; 3. a corner reflector; 4. a telescopic rod; 41. a fixed rod; 42. a slide bar; 43. a plug pin; 44. a jack; 5. an observation rod; 6. a round hole; 100. the device is used for measuring the surface deformation.

In the present utility model, all of the figures are schematic drawings which are intended to illustrate the principles of the utility model only and are not to scale.

Detailed Description

The utility model is described below with reference to the accompanying drawings.

The directional terms or qualifiers "upper", "lower", "front", "rear", "left", "right" and the like used in the present application are used with respect to the drawings to which reference is made. They are not intended to limit the absolute position of the parts involved, but may vary according to the specific circumstances.

Fig. 1 shows the structure of an apparatus 100 for surface deformation measurement according to the present utility model. As shown in fig. 1, the apparatus 100 for surface deformation measurement includes a base 1, a global GNSS receiver 2, and a corner reflector 3.

The base 1 is fixedly connected with the ground, and the universal GNSS receiver 2 and the corner reflector 3 are connected with the ground through the base 1. The universal GNSS receiver 2 adopts the GNSS technology, the corner reflector 3 adopts the time sequence InSAR technology, and the universal GNSS receiver 2 and the corner reflector 3 are mutually matched, so that the GNSS technology and the time sequence InSAR technology are combined, the data analysis and comparison are carried out on the same area by using the two technologies, the data analysis and the comparison are mutually compensated, various error correction and CR point precision verification in deformation monitoring are realized, and the precision of the observation result of the time sequence InSAR technology in the installation area is obviously improved.

It is easy to understand that the GNSS technology and the time sequence InSAR technology are both the prior art, and the specific operation method thereof is not a technical gist of the present utility model, and is not described herein.

In the present embodiment, the elevation of the generic GNSS receiver 2 is higher than the elevation of the corner reflector 3.

In this embodiment, the base 1 is provided in a disc shape with a thick middle and a thin edge, the bottom surface of the base 1 is provided in a plane, and a plurality of screw holes are uniformly provided on the base 1 in the circumferential direction, so that the base 1 can be fixed on the ground using bolts.

The universal GNSS receiver 2 is fixedly arranged on the base 1 by means of an observation rod 5. The universal GNSS receiver 2 is of the prior art, and the observation rod 5 is a stainless steel hollow steel tube.

The top of the observation rod 5 is provided with threads, and the universal GNSS receiver 2 is fixedly arranged on the top of the observation rod 5 in a threaded connection mode.

A bayonet 11 is provided at the center of the upper portion of the base 1, and the lower end portion of the observation rod 5 is provided in a shape matching the shape of the bayonet 11, so that the lower end of the observation rod 5 can be inserted into the bayonet 11 of the base 1.

The corner reflector 3 is provided on the base 1 by a plurality of telescopic rods 4, and the angle of the reflecting surface of the corner reflector 3 can be adjusted by the telescopic rods 4.

Specifically, the upper end of the telescopic rod 4 is hinged with the corner reflector 3, and the lower end of the telescopic rod 4 is connected with the base 1. A bayonet 11 is provided in the middle of the upper portion of the base 1, and the lower end portion of the telescopic rod 4 is provided in a shape matching the shape of the bayonet 11, so that the lower end of the telescopic rod 4 can be inserted into the bayonet 11 of the base 1.

As shown in fig. 3, the bayonet 11 is shaped as a circular through hole, and a notch is provided at an edge of the circular through hole, thereby preventing the telescopic rod 4 or the observation rod 5 from rotating in the circumferential direction after being inserted.

In the present embodiment, the corner reflector 3 is provided as a triangle, and one of the faces of the corner reflector 3 is a reflecting face.

Specifically, as shown in fig. 2, the corner reflector 3 is composed of a plurality of triangular stainless steel plates by welding. In the present embodiment, the corner reflector 3 includes three congruent isosceles right triangular plates and one equilateral triangular plate, which is a reflecting surface of the corner reflector 3. On each right-angle triangular plate, a plurality of round holes 6 are distributed along the right-angle side, so that satellite signals can be received conveniently.

Three congruent isosceles right triangular plates are respectively OAB, OAC and OBC, and the equilateral triangular plate is ABC.

In this embodiment, the number of the telescopic rods 4 is three, and the telescopic rods are respectively hinged with adjacent sides of the three isosceles right triangle plates, namely, on the OA line, the OB line and the OC line in fig. 2.

In the present embodiment, the telescopic rod 4 includes a fixed rod 41 fixedly connected with the base 1 and a sliding rod 42 hinged with the corner reflector 3, and the sliding rod 42 is slidably sleeved on the fixed rod 41.

A plurality of radially penetrating insertion holes 44 are provided in the sliding rod 42 and the fixing rod 41 in the axial direction, and the pins 43 can be slid in the radial direction into the insertion holes 44, thereby fixing the sliding rod 42 and the fixing rod 41 relatively. When the length of the telescopic rod 4 needs to be changed, after the latch 43 is taken out, the slide rod 42 is moved axially relative to the fixed rod 41, and after the slide rod is moved to the length required by the telescopic rod 4, the latch 43 is inserted into the insertion hole 44.

When the apparatus 100 for surface deformation measurement provided according to the present utility model is used, the angle of the reflecting surface of the corner reflector 3 is adjusted according to the difference in the orbit angle of the satellite. Specifically, when the angle of the reflecting surface of the corner reflector 3 is adjusted, the distance between the telescopic rods 4 and the length of each telescopic rod 4 need to be adjusted, and the two are matched with each other to adjust the angle of the reflecting surface of the corner reflector 3 to a desired angle. When the distance between the telescopic rods 4 is adjusted, the bases 1 are fixed on the ground according to the distance, and then the telescopic rods 4 are fixed on the bases 1 respectively.

Radar backscatter cross-section (RCS) is a physical quantity that measures the amount of ability of an object to reflect a signal to a radar signal receiving device, the larger the RCS, the greater the signal strength that is reflected in that direction and the easier it is to find. In the design of the corner reflector 3, it is necessary to calculate the RCS of the corner reflector 3 in order to accurately distinguish the corner reflector 3 from other background features. The RCS calculation formula of the corner reflector 3 is:

Wherein: σ _max denotes the maximum scattering cross section, a denotes the isosceles triangle right side length, λ denotes the radar wavelength, and l denotes the hypotenuse side length corresponding to the right side. It can be seen from the equation that RCS is proportional to the side length of the reflector 3 and inversely proportional to the radar wavelength.

Table 1 comparison of maximum RCS for different sized reflectors 3

Table 1 shows the maximum radar scattering interfaces of three corner reflectors of different sizes on ERS and Radarsat satellite images, whereThe area size of the reflection surface of the corner reflector 3 is shown, and dB represents RCS per unit area. The RCS of a feature is typically negative, such as: the desert area is-22 to-17 dB, the vegetation coverage area is-13 to-10 dB, and the mountain area is-8 to-5 dB, so that the corner reflector 3 is installed in a flat area with a certain range, far away from a building, and can be easily identified through the intensity information of an image.

The design principle of the corner reflector 3 requires that the incident electromagnetic wave reaches the reflecting surface of the corner reflector 3 to be reflected back in the reverse direction of the original path, so that the maximum RCS can be obtained. It is apparent that the condition for obtaining the maximum RCS is that the direction of the normal OE in fig. 2 is parallel to the radar incident direction, i.e. the radar incident ray is perpendicular to the plane ABC.

For this reason, it is necessary to rotate the corner reflector 3 upward by an angle along the O-point, i.e., raise the BC edge from the position shown in fig. 2 to the position shown in fig. 4.

As shown in fig. 4, assuming that BC is parallel to the satellite flight direction, OF is a plumb line, OE is parallel to the incident light when BC OF the corner reflector 3 is lifted up around O to D, θ is the radar incident angle, and D' is the projection OF D on the horizontal plane. The above values satisfy the following formulas:

DD′＝OD×sin∠DOD′,AOF+DOF＝90°,DOD′+DOF＝90°,DOD′＝AOE-θ,DD′＝OD×sin(AOE-θ)

The DD' value is different for different satellites because the angles of incidence are different. Let oa=1 meter, the DD' values for several satellites are shown in table 2.

TABLE 2 comparison of several satellites DD'

The DD' value is inversely proportional to the angle of incidence of the SAR satellites, and the BC edge should be rotated downward about the O-point when the angle of incidence is greater than 54.74.

The following problems should be noted in the process of mounting the corner reflector 3.

Depending on the SAR data acquisition mode to be selected, the satellite is ascending or descending, the azimuth angle of the bottom side (BC) of the corner reflector 3 is adjusted, and the bottom side of the corner reflector is made parallel to the satellite flight direction, as shown in FIGS. 5 and 6.

As shown in fig. 5, the open face ABC should face west when the satellite is in the up-track mode. As shown in fig. 6, the opening face ABC should face eastward when the satellite is in the down-track mode. At the same time, rotated clockwise (down-orbit) or counter-clockwise (up-orbit) by an angle (alpha-90 deg.), alpha being the satellite orbit tilt angle. The azimuth angle of the bottom edge of the corner reflector (the included angle between the bottom edge and the north-south direction) and the satellite orbit inclination angle alpha, and the latitude of the corner reflectorThe more accurate relationship between:

When the SAR satellite acquired data mode is the ascending orbit, the cos alpha is positively taken; otherwise, cos α is taken negative before.

The elevation angle of the corner reflector 3 is adjusted according to the incidence angle of the SAR satellite to be selected, so that the normal direction of the corner reflector 3 (refer to the line from the vertex O of the corner reflector 3 to the center of the equilateral triangle opening surface ABC) is parallel to the radar incidence direction (note that the elevation angle of the corner reflector is fixed and does not change with the place, while the bottom azimuth angle changes with the place latitude).

The corner reflector 3 can be finely adjusted (azimuth angle and elevation angle directions) in the wild, and has considerable stability, and can not deflect in the presence of strong wind.

The corner reflector 3 should be placed as far as possible at a place where the background reflection characteristic is weak, away from the slope of the mountain bag or ridge facing the satellite, so as to extract its position in the SAR image.

The corner reflector 3 should be installed as far as possible from objects that are prone to multipath effects, typically more than 100 meters.

The vertex O of the corner reflector 3 should correspond as much as possible to the ground GPS point in order to perform fusion of the InSAR data and the GPS data.

In the description of the present utility model, the meaning of "a plurality" is two or more, unless explicitly defined otherwise.

In the present utility model, unless explicitly specified and limited otherwise, the terms "mounted," "connected," "secured," and the like are to be construed broadly and may be, for example, fixedly connected, detachably connected, or integrally connected; can be mechanically or electrically connected; can be directly connected or indirectly connected through an intermediate medium, and can be communication between two elements. The specific meaning of the above terms in the present utility model can be understood by those of ordinary skill in the art according to the specific circumstances.

In the description of the present specification, a description referring to terms "one embodiment," "some embodiments," "examples," "specific examples," or "some examples," etc., means that a particular feature, structure, material, or characteristic described in connection with the embodiment or example is included in at least one embodiment or example of the present utility model. In this specification, schematic representations of the above terms do not necessarily refer to the same embodiments or examples. Furthermore, the particular features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples.

Finally, it should be noted that the above description is only of a preferred embodiment of the utility model and is not to be construed as limiting the utility model in any way. Although the utility model has been described in detail with reference to the foregoing embodiments, it will be apparent to those skilled in the art that modifications may be made to the techniques described in the foregoing examples, or equivalents may be substituted for elements thereof. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present utility model should be included in the protection scope of the present utility model.

Claims (10)

1. An apparatus for surface deformation measurement, comprising:

the base (1) is fixedly connected with the ground;

The universal GNSS receiver (2) is fixedly arranged on the base (1);

The angle reflector (3), angle reflector (3) are in through a plurality of telescopic links (4) setting on base (1), through the position of adjusting telescopic link (4) and base (1), and adjust telescopic length of telescopic link (4) can adjust the angle of the reflecting surface of angle reflector (3).

2. Device for surface deformation measurement according to claim 1, characterized in that the corner reflector (3) is arranged as a triangle, one of the faces of the corner reflector (3) being a reflecting face.

3. The device for surface deformation measurement according to claim 2, characterized in that the corner reflector (3) comprises three congruent isosceles right triangular plates and one equilateral triangular plate, which is the reflecting surface of the corner reflector (3).

4. A device for surface deformation measurement according to claim 3, characterized in that the number of telescopic rods (4) is three.

5. Device for surface deformation measurement according to claim 4, characterized in that three said telescopic rods (4) are hinged to the adjacent sides of three isosceles right triangle plates, respectively.

6. Device for surface deformation measurement according to any one of claims 1 to 5, characterized in that the telescopic rod (4) comprises a fixed rod (41) fixedly connected with the base (1) and a sliding rod (42) hinged with the corner reflector (3), the sliding rod (42) being slidably sleeved on the fixed rod (41).

7. Device for surface deformation measurement according to claim 6, characterized in that at least one radially sliding pin (43) is provided on the sliding rod (42), a plurality of insertion holes (44) are provided on the fixed rod (41) in the axial direction, the pin (43) being insertable into the insertion holes (44) so as to fix the sliding rod (42) with respect to the fixed rod (41).

8. Device for surface deformation measurement according to any one of claims 1 to 5, characterized in that the generic GNSS receiver (2) is fixedly connected to the base (1) by means of an observation rod (5).

9. Device for surface deformation measurement according to any one of claims 1 to 5, characterized in that the elevation of the generic GNSS receiver (2) is higher than the elevation of the corner reflector (3).

10. Device for surface deformation measurement according to any one of claims 1-5, characterized in that a bayonet (11) is provided on the base (1), the lower end of the telescopic rod (4) being shaped to match the bayonet (11).