Rainfall shielding target terahertz one-dimensional range profile measuring device

Abstract

The invention relates to the technical field of distance measurement, in particular to a device for measuring a terahertz one-dimensional range profile of a rainfall shielding target. The device comprises a rainfall channel, a terahertz radar, a target and a rotary table. The rainfall channel is a uniform-section channel with a rectangular cross section, the rainfall channel is provided with a plurality of rainfall devices, each rainfall device comprises a plurality of nozzles arranged at the top of the rainfall channel at intervals, and the rainfall devices are connected in parallel and are independently controlled. The terahertz radar is arranged on the outer side of the front end of the rainfall channel and located on the central extension line of the end face of the front end. The target is arranged on the outer side of the rear end of the rainfall channel and located on the center extension line of the rear end face, and the target is placed on the rotary table and rotates along with the rotary table. The distance between the terahertz radar and the target meets the condition that the radar beam of the terahertz radar does not interfere with the rainfall channel and completely covers the target. The working condition of the terahertz radar in a rainfall environment can be effectively simulated, and a one-dimensional distance image of a target shielded by a rain curtain can be obtained by using the terahertz radar.

Description

Technical Field

[0001] The invention relates to the technical field of distance measurement, and in particular to a terahertz one-dimensional distance profile measurement device for a target shielded by rain. Background Art

[0002] Terahertz radar uses terahertz waves as information carriers to detect targets. Compared with microwave radar, terahertz radar has a short wavelength, large bandwidth, and extremely high spatial, temporal and frequency resolution, which can achieve more accurate and higher frame rate detection of target position, speed and shape. Compared with laser radar, terahertz waves have a stronger ability to penetrate smoke, dust and sand.

[0003] However, the scattering and absorption of raindrops will seriously increase the transmission loss of terahertz waves and reduce the detection performance of terahertz radar. In order to realize the detection and application of terahertz radar in rainfall environment, it is necessary to conduct in-depth research on the transmission characteristics of terahertz waves in rainfall environment. Summary of the invention

[0004] The purpose of the present invention is to provide a terahertz one-dimensional range profile measurement device for a target shielded by rain, so as to obtain a one-dimensional range profile of a target shielded by rain using a terahertz radar.

[0005] In order to achieve the above object, the present invention provides a terahertz one-dimensional range profile measurement device for a target shielded by rain, comprising:

[0006] The rainfall channel is a rectangular channel with equal cross-section. The rainfall channel is provided with multiple rainfall devices. Each rainfall device includes multiple nozzles arranged at intervals on the top of the rainfall channel. The rainfall devices are connected in parallel and are controlled individually to adjust the rainfall amount.

[0007] The terahertz radar is arranged outside the front end of the rainfall channel and is located on the central extension line of the front end surface;

[0008] The target is arranged outside the rear end of the rainfall channel and is located on the central extension line of the rear end surface. The target is placed on the turntable and can rotate with the turntable.

[0009] The distance between the terahertz radar and the target satisfies: the radar beam of the terahertz radar does not interfere with the rainfall channel and completely covers the target.

[0010] Optionally, the elevation direction of the radar beam does not interfere with the rainfall channel, and the distance from the terahertz radar to the rear end face of the rainfall channel satisfies:

[0011]

[0012] The azimuth of the radar beam does not interfere with the rainfall channel, and the distance from the terahertz radar to the rear end of the rainfall channel satisfies:

[0013]

[0014] Among them, H is the height of the rainfall channel, W is the height of the rainfall channel, α1 is the elevation angle of the radar beam; α2 is the azimuth angle of the radar beam;

[0015] The distance from the terahertz radar to the rear end of the rainfall channel is {d 后1 , d 后2} in the small value.

[0016] Optionally, the target is a sphere;

[0017] The radar beam completely covers the target in its elevation direction, and the distance between the terahertz radar and the target satisfies:

[0018]

[0019] The azimuth of the radar beam completely covers the target, and the distance between the terahertz radar and the target satisfies:

[0020]

[0021] Wherein, R is the radius of the target, D is the distance between the terahertz radar and the target, and D=dfront+L+K+R, dfront is the distance from the terahertz radar to the front end face of the rainfall channel, L is the distance from the front end face to the rear end face of the rainfall channel, and K is the distance between the rear end face of the rainfall channel and the target;

[0022] Assuming that the elevation direction of the radar beam completely covers the target, the minimum distance d from the terahertz radar to the front end of the rainfall channel is 1, and the azimuth direction of the radar beam is

[0023] When the target is fully covered, the minimum distance from the terahertz radar to the front end of the rainfall channel is dfront2, then:

[0024]

[0025] The distance from the terahertz radar to the front end of the rainfall channel is {d 前1 , d 前2} in the large value.

[0026] Optionally, a measuring cylinder for measuring rainfall is provided in the rainfall channel, and the measuring cylinder is located below the rainfall area.

[0027] Optionally, the rainfall channel is a channel formed by an inverted U-shaped frame.

[0028] Optionally, each rainfall device also includes a water pipe, a plurality of nozzles arranged at intervals are installed on the water pipe, a control valve is provided on the water pipe, the water pipes of each rainfall device are connected in parallel and connected to the outlet pipe of a water pump, and water from a water source is supplied to each water pipe through the water pump.

[0029] Optionally, the rainfall shielding target terahertz one-dimensional range profile measurement device further includes a controller, the control valve is a solenoid valve, and the controller is connected to the water pump and the solenoid valve for controlling the water pump and the solenoid valve.

[0030] Optionally, a filter is provided on the water outlet pipe.

[0031] The above technical solution of the present invention has the following advantages:

[0032] The terahertz one-dimensional distance image measuring device for a target obscured by rain provided by the present invention comprises a rain channel, a terahertz radar, a target and a turntable. The rain channel is an equal-section channel with a rectangular cross-section. The rain channel is provided with a plurality of rain devices. Each rain device comprises a plurality of nozzles arranged at intervals on the top of the rain channel. The rain devices are connected in parallel and are controlled separately. The terahertz radar is arranged outside the front end of the rain channel and is located on the central extension line of the front end face. The target is arranged outside the rear end of the rain channel and is located on the central extension line of the rear end face. The target is placed on the turntable and can rotate with the turntable. The distance between the terahertz radar and the target satisfies that: the radar beam of the terahertz radar does not interfere with the rain channel and completely covers the target. It can effectively simulate the working condition of the terahertz radar in a rainy environment, and realize the use of the terahertz radar to obtain a one-dimensional distance image of the target obscured by the rain curtain. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] The drawings of the present invention are provided for illustrative purposes only, and the proportions and quantities of the components in the drawings may not necessarily be consistent with the actual products.

[0034] Figure 1 is a schematic structural diagram of a terahertz one-dimensional range profile measurement device for a target shielded by rain in an embodiment of the present invention;

[0035] Figure 2 is a top view schematic diagram of the relationship between the terahertz radar and the rainfall channel in an embodiment of the present invention;

[0036] Figure 3 is a structural schematic diagram of a rainfall channel in an embodiment of the present invention;

[0037] Figure 4 yes Figure 3 A magnified schematic diagram of part A;

[0038] Figure 5 yes Figure 3 An enlarged schematic diagram of part B;

[0039] Figure 6 is a one-dimensional range image of the target in the case of no rain curtain shielding in the embodiment of the present invention;

[0040] Figure 7It is a one-dimensional range image of the target under the condition of rain curtain shielding in the embodiment of the present invention.

[0041] In the figure:

[0042] 1: Rainfall channel;

[0043] 11: Nozzle;

[0044] 12: Water pipe;

[0045] 13: Control valve;

[0046] 14: Water pump;

[0047] 15: Water source;

[0048] 16: Controller;

[0049] 17: Filter;

[0050] 18: Measuring tube;

[0051] 2: Terahertz radar;

[0052] 21: radar beam;

[0053] 3: Target;

[0054] 4: Turntable. DETAILED DESCRIPTION

[0055] In order to make the purpose, technical solution and advantages of the embodiments of the present invention clearer, the technical solution 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 part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0056] like Figure 1 and Figure 2 As shown, the terahertz one-dimensional range profile measuring device for a target obscured by rain provided in an embodiment of the present invention comprises a rain channel 1, a terahertz radar 2, a target 3 and a turntable 4. The rain channel is placed between the terahertz radar 2 and the target 3, and is used to simulate the imaging of the turntable of the terahertz radar ISAR (Inverse-Synthetic-Aperture-Radar) in rainy weather.

[0057] The rainfall channel 1 is a channel of equal cross-section with a rectangular cross-section. The rainfall channel 1 is provided with multiple rainfall devices. Each rainfall device includes a plurality of nozzles 11 arranged at intervals on the top of the rainfall channel 1. The rainfall devices are connected in parallel and are controlled individually. One or more rainfall devices can be opened to adjust the rainfall amount.

[0058] The terahertz radar 2 is arranged outside the front end of the rainfall channel 1 and is located on the central extension line of the front end surface.

[0059] The target 3 is arranged outside the rear end of the rainfall channel 1 and is located on the central extension line of the rear end surface. The target 3 is placed on the turntable 4 and can rotate with the turntable 4 .

[0060] It should be noted that the target 3 and the turntable 4 are both existing technologies. For example, the target 3 is a corner reflector, and the turntable 4 is a rotating structure that can rotate at a constant speed, which will not be described in detail here.

[0061] The distance between the terahertz radar 2 and the target 3 satisfies that: the radar beam 21 of the terahertz radar 2 does not interfere with the rainfall channel 1 and completely covers the target 3 .

[0062] See also Figure 3 As shown, in one example, a measuring tube 18 for measuring rainfall is provided in the rainfall channel 1. The measuring tube 18 is located below the rainfall area and is used to collect precipitation and check the rainfall.

[0063] In one example, the rainfall channel 1 is a channel formed by an inverted U-shaped frame.

[0064] In one example, see Figure 3 to Figure 5 As shown, each rainfall device also includes a water pipe 12, and a plurality of nozzles 11 arranged at intervals are installed on the water pipe 12. A control valve 13 is provided on the water pipe 12. The water pipes 12 of each rainfall device are connected in parallel and connected to the outlet pipe of a water pump 14. Water from a water source 15 is supplied to each water pipe 12 through the water pump 14.

[0065] In order to improve the degree of automation, in one example, the terahertz one-dimensional range profile measurement device for a rain-shielded target further includes a controller 16 , the control valve 13 is a solenoid valve, and the controller 16 is connected to the water pump 14 and the solenoid valve for controlling the water pump 14 and the solenoid valve.

[0066] To avoid clogging the nozzle 11, in one example, see Figure 5 As shown, a filter 17 is provided on the water outlet pipe of the water pump 14 .

[0067] In a preferred embodiment, the pitch direction of the radar beam 21 does not interfere with the rainfall channel 1, and the distance d1 from the terahertz radar 2 to the rear end face of the rainfall channel 1 satisfies:

[0068]

[0069] The azimuth direction of the radar beam 21 does not interfere with the rainfall channel 1, and the distance d2 from the terahertz radar 2 to the rear end face of the rainfall channel 1 satisfies:

[0070]

[0071] Among them, H is the height of the rainfall channel, W is the height of the rainfall channel, α1 is the elevation angle of the radar beam; α2 is the azimuth angle of the radar beam;

[0072] The distance from the terahertz radar 2 to the rear end of the rainfall channel 1 is {d 后1 , d 后2} in the small value.

[0073] In a preferred embodiment, the target 3 is a sphere. The radar beam 21 completely covers the target 3 in the elevation direction, and the distance D between the terahertz radar 2 and the target 3 satisfies:

[0074]

[0075] The azimuth direction of the radar beam 21 completely covers the target 3, and the distance D between the terahertz radar 2 and the target 3 satisfies:

[0076]

[0077] Among them, R is the radius of the target, D is the distance between the terahertz radar and the target, and D=dfront+L+K+R, dfront is the distance from the terahertz radar to the front end face of the rainfall channel, L is the distance from the front end face to the rear end face of the rainfall channel, and K is the distance between the rear end face of the rainfall channel and the target.

[0078] Assuming that when the radar beam 21 completely covers the target 3 in elevation, the minimum distance from the terahertz radar 2 to the front end face of the rainfall channel 1 is dfront1, and when the radar beam 21 completely covers the target in azimuth, the minimum distance from the terahertz radar 2 to the front end face of the rainfall channel 1 is dfront2, then

[0079]

[0080] The distance from the terahertz radar 2 to the front end of the rainfall channel 1 is {d 前1 , d 前2} in the large value.

[0081] In a specific embodiment, the size of the rainfall channel 1 is 5m×3m×3m (length×width×height), and the effective rainfall area is 1 to 30m 2 The effective rainfall height is 3m. There are three rainfall devices to control the rainfall intensity. The continuous variation range of rainfall intensity is 20 to 220mm / h, and the raindrop size control range is 0.3 to 6mm.

[0082] The frequency of the terahertz radar 2 is 220 GHz, and the width of the radar beam 21 is 4.7°×2.3° (azimuth angle×pitch angle). The positional relationship between the terahertz radar 2 and the rainfall channel 1 is as follows: Figure 2As shown, since the radar viewing angle is directly illuminating the rainfall channel 1, the distance selection factor between the terahertz radar 2 and the target 3 is only related to the width of the radar beam 21 and the size of the rainfall channel 1. Figure 1 and Figure 2 As shown, according to the fact that neither the horizontal nor the vertical beam hits the rainfall channel 1, it is the appropriate distance from the terahertz radar 2 to the rear end face of the rainfall channel, then,

[0083] Pitch direction:

[0084]

[0085] Direction:

[0086]

[0087] The distance from the terahertz radar 2 to the rear end of the rainfall channel 1 is {d 后1 , d 后2} in the small value.

[0088] The distance from the terahertz radar 2 to the rear end of the rainfall channel 1 is dback = d 前 +L

[0089] Ideally, d 前 +L is limited by the horizontal beam width, so d 前 +L≤36.5m, i.e. d 前 ≤31.5m.

[0090] At the same time, the radar beam 21 covers the target 3 relationship and needs to satisfy the following conditions at the same time:

[0091] Pitch direction:

[0092]

[0093] Direction:

[0094]

[0095] but:

[0096]

[0097]

[0098] Substituting L=5, K=1, R=0.5, we get:

[0099] d 前1 ≥18.4m

[0100] d 前2 ≥5.7m

[0101] The distance d from the terahertz radar to the front end of the rainfall channel前 Take {d 前1 , d 前2}middle

[0102] So d 前 ≥18.4m.

[0103] In summary, the distance d between the radar and the front end of the gantry is 前 Should meet 18.4m≤d 前 ≤31.5m.

[0104] It is worth noting that in actual situations, it is not strictly necessary that both the horizontal and vertical beams do not hit the rainfall channel 1. The d 前 As long as the test results are within the acceptable range,

[0105] In one example, according to the radar beam width and the size of the rainfall channel, a suitable distance between the terahertz radar and the target is determined. For example, the target 3 is placed at a distance of about 50m from the terahertz radar, and the target 3 is placed on a turntable 4 and rotated at a set speed. The terahertz radar 2 is used to measure the echo of the target 3, and a one-dimensional range image of the target 3 can be obtained after data processing. It should be noted that obtaining a one-dimensional range image of a target through data processing is an existing technology and will not be described in detail here. Figure 6 and Figure 7 The one-dimensional range images of the target in the case of no rain curtain and under rain curtain cover are shown. By comparison, it can be seen that rainfall has a greater impact on the amplitude of the signal, and the target is at 50.26m.

[0106] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that not every embodiment contains only one independent technical solution. In the absence of a conflict of solutions, the various technical features mentioned in each embodiment can be combined in any manner to form other implementation methods that can be understood by those skilled in the art.

[0107] In addition, without departing from the scope of the present invention, the technical solutions described in the aforementioned embodiments may be modified, or some of the technical features may be replaced by equivalents, without causing the essence of the corresponding technical solutions to depart from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A terahertz one-dimensional range profile measurement device for a target obscured by rain, characterized in that: include: The rainfall channel is a channel of equal cross-section with a rectangular cross section. The rainfall channel is provided with multiple rainfall devices, each of which includes multiple nozzles arranged at intervals on the top of the rainfall channel. The rainfall devices of each channel are connected in parallel and are controlled separately to adjust the rainfall amount. A terahertz radar is arranged outside the front end of the rainfall channel and is located on the central extension line of the front end surface; A target is arranged outside the rear end of the rainfall channel and is located on the central extension line of the rear end surface. The target is placed on a turntable and can rotate with the turntable. The distance between the terahertz radar and the target satisfies that: the radar beam of the terahertz radar does not interfere with the rainfall channel and completely covers the target.

2. The device for measuring the one-dimensional terahertz range profile of a target obscured by rain according to claim 1, characterized in that: The pitch direction of the radar beam does not interfere with the rainfall channel, and the distance from the terahertz radar to the rear end face of the rainfall channel satisfies: The azimuth of the radar beam does not interfere with the rainfall channel, and the distance from the terahertz radar to the rear end face of the rainfall channel satisfies: Among them, H is the height of the rainfall channel, W is the height of the rainfall channel, α1 is the elevation angle of the radar beam; α2 is the azimuth angle of the radar beam; The distance from the terahertz radar to the rear end surface of the rainfall channel is {d 后1 , d 后2 } in the small value.

3. The device for measuring the one-dimensional terahertz range profile of a target obscured by rain according to claim 2, characterized in that: The target is a sphere; The radar beam completely covers the target in the elevation direction, and the distance between the terahertz radar and the target satisfies: The azimuth direction of the radar beam completely covers the target, and the distance between the terahertz radar and the target satisfies: Wherein, R is the radius of the target, D is the distance between the terahertz radar and the target, and D=dfront+L+K+R, dfront is the distance from the terahertz radar to the front end face of the rainfall channel, L is the distance from the front end face to the rear end face of the rainfall channel, and K is the distance between the rear end face of the rainfall channel and the target; Assuming that when the elevation direction of the radar beam completely covers the target, the minimum distance from the terahertz radar to the front end face of the rainfall channel is dfront1, and when the azimuth direction of the radar beam completely covers the target, the minimum distance from the terahertz radar to the front end face of the rainfall channel is dfront2, then: The distance from the terahertz radar to the front end of the rainfall channel is {d 前1 , d 前2 } in the large value.

4. The device for measuring the one-dimensional terahertz range profile of a target obscured by rain according to claim 1, characterized in that: A measuring cylinder for measuring rainfall is arranged in the rainfall channel, and the measuring cylinder is located below the rainfall area.

5. The device for measuring the one-dimensional terahertz range profile of a target obscured by rain according to claim 1, characterized in that: The rainfall channel is a channel formed by an inverted U-shaped frame.

6. The device for measuring the one-dimensional terahertz range profile of a target obscured by rain according to claim 5, characterized in that: Each of the rainfall devices also includes a water pipe, and a plurality of the nozzles arranged at intervals are installed on the water pipe. A control valve is provided on the water pipe. The water pipes of the rainfall devices of each route are connected in parallel and connected to the outlet pipe of a water pump, and water from a water source is supplied to each water pipe through the water pump.

7. The device for measuring the one-dimensional terahertz range profile of a target obscured by rain according to claim 6, characterized in that: It also includes a controller, the control valve is a solenoid valve, and the controller is connected to the water pump and the solenoid valve to control the water pump and the solenoid valve.

8. The device for measuring the one-dimensional terahertz range profile of a target obscured by rain according to claim 6, characterized in that: A filter is arranged on the water outlet pipe.

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