Interference, refraction and reflection integrated global satellite navigation system environment remote sensing monitoring device

Abstract

The invention designs an interference, refraction and reflection integrated global satellite navigation system (GNSS) environment remote sensing monitoring device, which comprises a bracket for fixing an antenna and a receiver, the antenna and the receiver are connected through a cable, and an external power supply supplies power to the receiver; and the antenna is used for receiving direct / interference, refraction and reflection signals of the GNSS satellite. Comprising a right-handed circularly polarized antenna which receives direct / interference signals of a GNSS satellite, a right-handed circularly polarized antenna which is arranged on the earth surface and is used for receiving refraction signals of a medium above the earth surface, and four polarized (left-handed, right-handed, vertical and horizontal) reflection antennas which receive reflection signals of the earth surface environment. And the receiver is used for receiving signals and processing data. The system is provided with six signal channel interfaces and an observed quantity processing device. The invention discloses a Beidou environment remote sensing monitoring equipment prototype mother set oriented to multiple application scenes, provides a test device for prototype test verification in typical application scenes, and supports future multi-scene customized equipment model development.

Description

Technical Field

[0001] The present invention relates to an environmental remote sensing monitoring device, and in particular to an interference, refraction and reflection integrated global satellite navigation system (GNSS) environmental remote sensing monitoring device. Background Art

[0002] The use of navigation satellites (GNSS, such as Beidou) for remote sensing detection is a hot topic at the forefront of international science and technology. After nearly a decade of rapid development, it is transforming from theoretical method research to software and hardware product development. Compared with the more mature Beidou positioning and navigation equipment, the research and development of Beidou environmental remote sensing monitoring equipment will be the focus of attention in this field in the next 3-5 years. Judging from the current development status at home and abroad, Beidou environmental remote sensing monitoring equipment is currently showing a "positive" development driven by scientific problems. After 15 years, three observation modes of interference, refraction, and reflection have been discovered, and more than 20 observation capabilities related to ocean, land, and environmental parameters have been discovered, presenting a situation of "multiple modes corresponding to multiple scenarios."

[0003] However, in order to develop dedicated equipment for environmental remote sensing monitoring applications as soon as possible, that is, "reverse" development driven by application scenarios, it is necessary to change the thinking from "multiple modes corresponding to multiple scenarios" to "device styles dedicated to specific scenarios", so as to achieve stable and continuous monitoring of environmental parameters in clear application scenarios. In response to this demand, although many detection mechanisms and inversion algorithm models have been developed under different observation modes, the long-term goal of developing dedicated equipment for Beidou / GNSS environmental remote sensing monitoring still requires a large number of observation tests and verifications in various complex surface scenarios. Summary of the invention

[0004] In view of the defects in the existing technology, it is urgent to design a Beidou / GNSS environmental remote sensing monitoring equipment prototype "mother version" v1.0 for multiple application scenarios, so that prototype testing and verification can be carried out for various typical application scenarios, and then support the development of multiple "sub-version" equipment models customized for specific application scenarios in the future.

[0005] To achieve the above objectives, the technical solution adopted by the present invention is: an interference, refraction and reflection integrated global satellite navigation system environment remote sensing monitoring device, comprising: a bracket, an antenna and a receiver; The bracket is used to fix the antenna and the receiver; The antenna is used to receive direct / interference, refracted and reflected signals from the satellite; The antenna comprises: a right-hand circularly polarized antenna, which is arranged on the bracket and faces the zenith, and is used to receive direct or interference signals from the satellite; 1 right-hand circularly polarized antenna, set on the surface, used to receive the refracted signal of the medium above the surface; Four polarized reflection antennas are arranged on the bracket and used to receive the reflected signals from the surface environment; The receiver is used for receiving antenna signals and data processing; The antenna and the receiver are connected by a cable.

[0006] Specifically, the four polarized reflective antennas are left-handed, right-handed, vertical, and horizontal circularly polarized reflective antennas, respectively.

[0007] Furthermore, the four polarized reflective antennas face the nadir or a depression angle of 45 degrees.

[0008] Furthermore, the receiver includes 6 signal channel interfaces and an environmental parameter processing device.

[0009] Furthermore, the signal channel interface is respectively connected to one direct / interference signal receiving antenna, one refracted signal receiving antenna and four reflected signal receiving antennas, so as to realize the reception of observation data mainly based on signal-to-noise ratio, signal power and carrier phase.

[0010] Furthermore, the receiver has a digital signal processing module and a storage module inside; The digital signal processing module is used for receiving digital signals from direct / interference antennas, reflection antennas, and refraction antennas and for data processing; The digital signal processing module includes an RF front-end processing module and a baseband signal processing module; the RF signals from the direct / interference antenna, reflection antenna, and refraction antenna are processed through the RF front-end processing module to obtain intermediate frequency signals, and the intermediate frequency signals are processed through the baseband signal processing module to obtain carrier phase, signal power, and signal-to-noise ratio.

[0011] Furthermore, the bracket is erected above the observation medium.

[0012] In a second aspect, a solution of an antenna signal processing device is provided, comprising a plurality of signal receiving channels, a processing unit, and a storage unit; The plurality of signal receiving channels include a reflection channel, a direct / interference channel, and a refraction channel; the plurality of signal receiving channels are connected to a plurality of polarized antennas; The processing unit includes a data receiving unit, a radio frequency front-end processing unit, and a baseband signal processing unit; the number of the data receiving units is consistent with the number of the signal receiving channels and corresponds to each other; The processing unit integrates the observation data from the polarized antenna, performs RF front-end processing, and baseband signal processing; The processing unit transmits the processed data to the storage module; The communication module is used to transmit the data in the storage module to a local computer, or to copy the data via an external mobile hard disk or a computer.

[0013] Furthermore, the signal receiving channel specifically includes: 4 reflection channels, 1 direct / interference channel, and 1 refraction channel; The four reflection channels are respectively connected to left-hand, right-hand, vertical and horizontal circularly polarized reflection antennas; One of the direct / interference channels is connected to a right-hand circularly polarized antenna; One of the refraction channels is connected to a right-hand circularly polarized antenna.

[0014] In a third aspect, a method for processing a multi-mode antenna signal is provided, comprising the following steps: Acquire data from different observation modes; Different physical quantities are calculated by using the physical quantity calculation principles in interference mode, refraction mode and reflection mode; Transform the height of the reflecting surface through the geometric model; Transform reflection coefficient and reflectivity through physical model; Through the physical model, the refraction phase delay and the reflection phase delay are converted; The same parameters obtained from different observation modes are analyzed and compared, and the best solution suitable for inversion is finally obtained by selecting one of the two or taking the weighted average of the two.

[0015] Beneficial effects of the present invention: Through the collaborative idea of ​​interference, refraction and reflection observation modes, we can achieve multi-dimensional information coordination of signal phase, amplitude and polarization, realize the calculation of multiple physical quantities, and test the optimal observation mode or mode combination in different natural scenes. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 It is a schematic diagram of the overall structure of the present invention; Figure 2 It is a schematic diagram of the receiver structure of the present invention; Figure numerals: 100, bracket, 201, direct / interference signal receiving antenna (right-hand circular polarization), 202, refracted signal receiving antenna (right-hand circular polarization), 203, reflected signal receiving antenna (left-hand circular polarization), 204, reflected signal receiving antenna (right-hand circular polarization), 205, reflected signal receiving antenna (vertical polarization), 206, reflected signal receiving antenna (horizontal polarization), 300, receiver, 301, processing module, 302, storage module. DETAILED DESCRIPTION

[0018] To make the objects, advantages and features of the present invention more apparent, the following Figure 1 , 2 and specific implementation methods describe the present invention in detail.

[0019] like Figure 1 As shown, the interference, refraction and reflection integrated navigation satellite (GNSS, such as Beidou, etc.) environmental remote sensing monitoring device includes: The bracket 100 is used to fix the antenna and the receiver 300. The antenna and the receiver 300 are connected by a cable, and an external power supply is used to power the receiver; Antennas are used to receive direct / interference, refracted and reflected signals from satellites. They include a right-hand circularly polarized antenna 201 for receiving direct / interference signals from Beidou / GNSS navigation satellites, a right-hand circularly polarized antenna 202 placed on the ground to receive refracted signals from the medium above the ground, and four polarized (left-hand 203, right-hand 204, vertical 205, horizontal 206) reflection antennas for receiving signals reflected from the ground environment.

[0020] The receiver 300 has a digital signal processing device 301 and a storage module 302, which are used to receive digital signals from the direct (interference) antenna, the reflective antenna, and the refraction antenna and process data. And (1) the processing module includes a radio frequency front-end processing module and a baseband signal processing module. The radio frequency signal from the direct (interference) antenna, the reflective antenna, and the refraction antenna is processed by the radio frequency front-end processing module to obtain an intermediate frequency signal, and the intermediate frequency signal is processed by the baseband signal processing module to obtain a carrier phase, signal power, and signal-to-noise ratio.

[0021] (2) The storage module transmits data to the local computer through the communication module, or copies data through an external mobile hard disk / computer.

[0022] The observation data obtained based on the above three modes of antennas can realize the calculation of the following physical quantities: The calculation principle of the physical quantity in the interference mode is: the height of the reflecting surface. The interference mode directly receives the signal-to-noise ratio of the direct signal. , take the low elevation angle part (such as 5-30 degrees) where the multipath interference effect is more obvious, and get the multipath error after removing the trend term . is the direct signal amplitude, is the reflected signal amplitude, is the satellite altitude angle, is the oscillation frequency, is the phase shift. Use spectrum analysis to obtain Oscillation frequency . The reflective surface height is calculate.

[0023] The calculation principle of physical quantities in refraction mode is: Attenuation coefficient. The refraction mode directly receives the signal-to-noise ratio of the direct and refracted signals. The attenuation coefficient is calculated by Calculate. The normalized direct signal signal-to-noise ratio (direct signal intensity) is , the normalized refraction signal noise ratio (refraction signal intensity) is , the normalized reflection signal intensity is , is the product of the normalized direct signal intensity and the reflection coefficient, where the reflection coefficient can be calculated using the Fresnel formula. is the propagation distance of the signal in the medium.

[0024] Refraction phase delay. Construct the station-satellite double-difference carrier phase equation, that is, ,in, is the GNSS signal wavelength, is the phase measurement in units of periods, is the receiver 1 and 2 in the formula, In the formula Satellite identification; remove the baseline length, perform ambiguity estimation and cycle slip correction, remove error terms such as phase noise, and obtain the phase delay of the reflection path caused by the medium.

[0025] The calculation principle of physical quantities in reflection mode is: Reflectivity. The reflection mode directly receives the signal-to-noise ratio of the direct signal. , the power of the reflected signal ,in Including reflected power of different polarizations. Signal-to-noise ratio of reflected signal , noise power is a known quantity. The reflectivity is calculate.

[0026] Reflection phase delay. Construct the station-satellite double-difference carrier phase equation, that is, ,in, is the GNSS signal wavelength, is the phase measurement in units of periods, is the receiver 1 and 2 in the formula, In the formula Satellite identification; remove the baseline length, perform ambiguity estimation and cycle slip correction, remove error terms such as phase noise, and obtain the reflection phase delay caused by the medium.

[0027] Based on the completion of physical quantity solution, the inversion of multiple environmental parameters can be realized in different environmental scenarios, such as snow accumulation in pastoral areas and waterlogging.

[0028] In a specific application scenario: taking the inversion of snow parameters as an example, through the coordinated work of interference, refraction and reflection modes, the above device can realize the inversion of four parameters: snow depth, snow density, liquid water content and snow water equivalent.

[0029] Specific steps: 1) The data from different observation modes acquired by the storage module are transmitted to the local workstation, and different physical quantities are calculated by the above-mentioned interference mode, refraction mode, and reflection mode physical quantity calculation principles, namely, interference mode-reflection surface height, refraction mode-reflection coefficient, refraction phase delay, reflection mode-reflectivity, reflection phase delay; 2) Through the geometric model, the reflection surface height is converted into snow depth, through the physical model, the reflection coefficient and reflectivity are converted into dielectric constant and then into snow density or liquid water content, and through the physical model, the refraction phase delay and reflection phase delay are converted into snow water equivalent; 3) Analyze and compare the same parameters obtained from different observation modes, for example: analyze and compare the performance of snow water equivalent calculated by refraction phase delay and reflection phase delay under different dry and wet snow conditions, and finally obtain the best solution suitable for snow water equivalent inversion by selecting one of the two or weighted averaging the two. In the future, a special observation device for snow water equivalent, namely "sub-version", can be created based on this.

[0030] It should be pointed out that Figure 1 The arrows in the figure only indicate the propagation path of the navigation satellite signal, such as going downward and passing through the medium, being refracted, and being reflected on the surface of the medium.

[0031] It should be pointed out that the five antennas require that the bracket 100 be installed above the medium to be observed. For example, if measuring 50 cm of snow, the antenna needs to be at least 30 cm above the snow layer.

[0032] In addition, the upper limit of the installation height of the bracket 100 should meet the limit requirements of the interference mode.

[0033] In a specific embodiment, Figure 2 , a solution of an antenna signal processing module is proposed, including a processing module and a storage module; The processing module includes a radio frequency front-end processing unit and a baseband signal processing unit; The processing unit integrates the observation data from the polarized antenna, performs RF front-end processing, and baseband signal processing; The processing module transmits the processed data to the storage module.

[0034] Furthermore, it also includes a communication module for transmitting the data of the storage module to a local computer, or copying the data through an external mobile hard disk / computer.

[0035] It should be noted that the connection methods of the various parts of the present invention may include wired, wireless and other communication methods.

[0036] It should be understood that the various parts of the present invention can be implemented by hardware, software, firmware or a combination thereof. In the above-mentioned embodiments, a plurality of steps or methods can be implemented by software or firmware stored in a memory and executed by a suitable instruction execution system. For example, if implemented by hardware, it can be implemented by any one of the following technologies known in the art or their combination: a discrete logic circuit having a logic gate circuit for implementing a logic function for a data signal, a dedicated integrated circuit having a suitable combination of logic gate circuits, a programmable gate array (PGA), a field programmable gate array (FPGA), etc.

[0037] In addition, each functional module in each embodiment of the present invention may be integrated into a processing module, or each module may exist physically separately, or two or more modules may be integrated into one module. The above-mentioned integrated module may be implemented in the form of hardware or in the form of a software functional module. If the integrated module is implemented in the form of a software functional module and sold or used as an independent product, it may also be stored in a computer-readable storage medium.

[0038] The storage medium mentioned above can be a read-only memory, a magnetic disk or an optical disk, etc.

[0039] The above implementation modes are only used to illustrate the present invention, but not to limit the present invention. Ordinary technicians in the relevant technical field can make various changes and modifications without departing from the essence and scope of the present invention. Therefore, all equivalent technical solutions also belong to the scope of the present invention, and the patent protection scope of the present invention should be defined by the claims. The contents not described in detail in this specification belong to the prior art known to professional and technical personnel in this field.

Claims

1. A global satellite navigation system environment remote sensing monitoring device integrating interference, refraction and reflection, characterized in that: include: Bracket, antenna, receiver; The bracket is used to fix the antenna and the receiver; The antenna is used to receive direct / interference, refracted and reflected signals from the satellite; The antenna comprises: a right-hand circularly polarized antenna, which is arranged on the bracket and faces the zenith, and is used to receive direct or interference signals from the satellite; 1 right-hand circularly polarized antenna, set on the surface, used to receive the refracted signal of the medium above the surface; Four polarized reflection antennas are arranged on the bracket and used to receive the reflected signals from the surface environment; The receiver is used for receiving antenna signals and data processing; The antenna and the receiver are connected by cables.

2. The environmental remote sensing monitoring device according to claim 1, characterized in that: The four polarized reflective antennas are respectively left-handed, right-handed, vertical, and horizontal circularly polarized reflective antennas.

3. The environmental remote sensing monitoring device according to claim 2, characterized in that: The four polarized reflective antennas face the nadir or at a depression angle of 45 degrees.

4. The environmental remote sensing monitoring device according to claim 1, characterized in that: The receiver includes 6 signal channel interfaces and an environmental parameter processing device.

5. The environmental remote sensing monitoring device according to claim 4, characterized in that: The signal channel interface is respectively connected to one direct / interference signal receiving antenna, one refracted signal receiving antenna and four reflected signal receiving antennas, and is used to receive observation data mainly based on signal-to-noise ratio, signal power and carrier phase.

6. The environmental remote sensing monitoring device according to claim 4, characterized in that: The receiver has a digital signal processing module and a storage module inside; The digital signal processing module is used for receiving digital signals from direct / interference antennas, reflection antennas, and refraction antennas and for data processing; The digital signal processing module includes a radio frequency front-end processing module and a baseband signal processing module; The RF signals from the direct / interference antenna, reflection antenna, and refraction antenna are processed through the RF front-end processing module to obtain the intermediate frequency signal, and the intermediate frequency signal is processed through the baseband signal processing module to obtain the carrier phase, signal power, and signal-to-noise ratio.

7. The environmental remote sensing monitoring device according to any one of claims 1 to 6, characterized in that: The support is arranged above the observation medium.

8. An antenna signal processing device, characterized in that: It includes multiple signal receiving channels, a processing unit, and a storage unit; The plurality of signal receiving channels include a reflection channel, a direct / interference channel, and a refraction channel; the plurality of signal receiving channels are connected to a plurality of polarized antennas; The processing unit includes a data receiving unit, a radio frequency front-end processing unit, and a baseband signal processing unit; The number of the data receiving units is consistent with the number of the signal receiving channels and corresponds to each other; The processing unit integrates the observation data from the polarized antenna, performs RF front-end processing, and baseband signal processing; The processing unit transmits the processed data to the storage module; The communication module is used to transmit the data in the storage module to a local computer, or to copy the data via an external mobile hard disk or a computer.

9. An antenna signal processing device as claimed in claim 8, characterized in that: The signal receiving channels specifically include: 4 reflection channels, 1 direct / interference channel, and 1 refraction channel; The four reflection channels are respectively connected to left-hand, right-hand, vertical and horizontal circularly polarized reflection antennas; One of the direct / interference channels is connected to a right-hand circularly polarized antenna; One of the refraction channels is connected to a right-hand circularly polarized antenna.

10. An antenna signal processing method, characterized in that: The steps include: Acquire data from different observation modes; Different physical quantities are calculated by using the physical quantity calculation principles in interference mode, refraction mode and reflection mode; Transform the height of the reflecting surface through the geometric model; Transform reflection coefficient and reflectivity through physical model; Through the physical model, the refraction phase delay and the reflection phase delay are converted; The same parameters obtained from different observation modes are analyzed and compared, and the best solution suitable for inversion is finally obtained by selecting one of the two or taking the weighted average of the two.

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