Optical remote passive wind parameter determinator

Abstract

FIELD: measuring equipment.SUBSTANCE: invention relates to a device for determining wind parameters. The wind parameter determinator comprises a control and signal processing unit (1), as well as an optical-electronic module (2). The control and signal processing unit (1) includes an analogue-to-digital converter (13) and a module (14) for calculating correlation functions between signals. The optical-electronic module (2) includes three photodetectors (8) with signal amplification units (11), amplitude detection units (12), as well as an optical system (4) with a variable focal length, a diaphragm unit (7), an amplitude modulator (5) of the intensity of the background radiation flux with a reference modulation frequency.EFFECT: increase in the sensitivity of the device.1 cl, 1 dwg

Description

[0001] The invention relates to passive systems for meteorological monitoring of the atmosphere and can be used to improve the accuracy of information about the wind state of the atmosphere, obtained from different distances from the object.

[0002] A remote method for determining the average speed and direction of horizontal wind is known, based on the registration of optical images of observed objects (RU Patent No. 2823690, registered on July 29, 2024).

[0003] The disadvantage of this patent is the need for a remote object, contrasting with the surrounding environment, to change the characteristics, the image of which determines the parameters of the movement of the air mass located between the object and the observation point.

[0004] A remote passive wind parameter determinator is known, operating on physical principles similar to those claimed for obtaining information on atmospheric wind parameters (RU Patent No. 2801433, registered on 08 / 08 / 2023).

[0005] The disadvantages of this technical solution are the complexity of implementing control over the shape of signals and their phase delay in each period of oscillation of analog signals taken from the outputs of signal amplifiers of photodetector devices (PDD), associated with their incomplete repeatability and distortions caused by the superposition of amplifier noise and effects that distort the shape of signals, random turbulent phenomena of the atmosphere.

[0006] The closest in technical essence and achieved result is a non-contact passive wind parameter determinator, operating on physical principles similar to the declared one for obtaining information on atmospheric wind parameters (RU Patent No. 2839260, registered on October 7, 2024).

[0007] The disadvantages of this technical solution are a sharp decrease in the sensitivity of the process of recording background radiation modulated by moving air masses with a decrease in the recorded wind speeds and the associated decrease in the frequency of modulation of the intensity of background radiation due to the increasing influence of low-frequency noise of the photodetector and amplifier; the influence of noise becomes greater the lower the recorded speed, up to the point of loss of functionality.

[0008] The technical result of the proposed solution is maintaining the sensitivity of the measurement process regardless of the recorded wind speed value by introducing an amplitude modulator of the background radiation flux. This shifts the recorded signal to a higher frequency region determined by the amplitude modulator frequency, where the influence of low-frequency noise from the photodetector and amplifier is negligible. An amplitude detector with amplification is introduced into the signal amplification path to subsequently isolate the useful signal. The isolated analog useful signal from each of the three photodetectors is digitized, accumulated, and averaged over long time intervals for further processing and obtaining a stable average result unaffected by random atmospheric phenomena such as turbulence, short-term gusts of wind, etc.To extract information about wind speed, methods of correlation analysis of recorded digital signals are used.

[0009] The application of correlation methods for measuring wind speed is based on the hypothesis of the “frozen structure of the atmosphere”, according to which the spatial distributions of inhomogeneities of moving air masses, including fluctuations in the concentrations of various types of aerosol scatterers and turbulent formations, retain their structure over a certain period of time, moving as a single whole within an extended section of the atmosphere and consistently amplitude-modulating the background radiation within this section in a similar manner.

[0010] The correlation functions used to determine the time delays between signals coming from different FPUs, proportional to the speed of movement of air masses, are written as follows:

[0011]

[0012]

[0013] τ 12 - the delay time between signals from FPU 1 and 2, proportional to the speed of movement of air masses between the direction of sight formed by FPU 1 and 2 and the optical system.

[0014] τ 13 - the delay time between signals from FPU 1 and 3 is proportional to the speed of movement of air masses between the direction of sight formed by FPU 1 and 3 and the optical system.

[0015] g1, g2, g3 - amplified signals from FPU 1, 2, 3 in digital format.

[0016] The technical result is achieved in that the wind parameter determinator is an optical remote passive one, comprising a control and signal processing unit for photoreceiving devices, an optoelectronic module that contains three photoreceiving devices with amplification units, amplitude detection with signal amplification, an optical system with a variable focal length, a diaphragm unit that automatically regulates the background radiation flow received by the optoelectronic module, an amplitude modulator of the intensity of the background radiation flow with a reference modulation frequency received by the photoreceiving devices, wherein each photoreceiving device in combination with the optical system forms one of three angular sectors of the optoelectronic module located next to each other, within which the photoreceiving device receives a background radiation flow with an intensity modulated by the inhomogeneities of the air mass moving and crossing the sector,wherein from the output of each of the photodetectors, the variable component of the electrical signal with a reference frequency is removed, amplified, detected and digitized, modulated by a variable low-frequency signal determined by the movement of the air mass, a change in the intensity of the background radiation flow received by each photodetector, in order to isolate time delays between low-frequency signals repeated at the outputs of the photodetectors, corresponding to the modulation of the background radiation by moving atmospheric formations, obtained on the basis of calculating mutual correlation functions in the module for calculating correlation functions between signals from the outputs of the analog-digital converter, proportional to the speed of movement of the air mass, as a single whole, between the angular sectors of the optoelectronic module in a plane perpendicular to the direction of the optical axis of the optoelectronic module,wherein the angular dimensions of the sectors of the optoelectronic module formed by the optical system, with a priori known average dimensions of the most frequently occurring atmospheric inhomogeneities that, when moving, temporarily modulate the intensity of background radiation, make it possible to localize the position of the region of space where the maximum modulation of background radiation by a moving air mass occurs, making the main contribution to the information on the wind speed vector, a change in the angular dimensions of the sectors, by changing the focal length of the optical system of the optoelectronic module, makes it possible to determine the parameters of the projection of the wind speed at different distances from the wind parameter detector, and the applied amplitude detection of the received background radiation flow ensures the maintenance of the required sensitivity level of the wind parameter detector when recording operating signals, regardless of the wind speed.

[0017] The essence of the technical solution is to maintain the sensitivity level of the process of recording background radiation modulated by moving atmospheric formations, regardless of the modulation frequency associated with their speed of movement.

[0018] A comparison of the proposed solution with known technical solutions shows that it has a new set of essential features, which, together with already known features, make it possible to successfully achieve the stated goal.

[0019] The invention is illustrated by graphic material, where the drawing shows the process of determining wind parameters and a passive optical remote wind parameter determinator. Here is Fig. 1:

[0020] 1. - Control and signal processing unit FPU.

[0021] 2. - Optical-electronic module (OEM).

[0022] 3. - Three viewing directions (non-coplanar directions of receiving radiation from the atmosphere), formed by the OEM.

[0023] 4. - OEM variable focal length optical system.

[0024] 5. - Amplitude modulator of background radiation OEM.

[0025] 6. - OEM case.

[0026] 7. - The mechanical diaphragm of the OEM automatically regulates the magnitude of the passing radiation flux; the signal controlling the position of the diaphragm is taken from the output of the FPU.

[0027] 8. - Highly sensitive photoelectric detectors with signal pre-amplification units.

[0028] 9. - Angular sectors formed by the FPU and the optical system of the OEM, within which the FPU receives radiation from the atmosphere.

[0029] 10 - The area of ​​space where the angular sectors of 9 OEM 2 are localized.

[0030] 11. - FPU signal amplifiers 8.

[0031] 12. - Amplitude signal detectors with amplification.

[0032] 13. - Three-channel ADC, which converts amplified and detected analog signals from the FPU into digital format.

[0033] 14. - Module for calculating correlation functions for determining time delays between signals from the first and second FPU and the first and third FPU, proportional to the projections of the air mass velocity along the line between the first and second and the line between the first and third angular sectors 9 OEM 2.

[0034] 15. - An air mass moving as a single whole. (Fig. 2).

[0035] 16. - Average direction of movement of the air mass in the plane perpendicular to the optical axis of the OEM 2. (Fig. 2).

[0036] 17. - The transverse component of the wind speed vector in the region of space 10, where the angular sectors 9 of the OEM 2 are localized. (Fig. 1).

[0037] Operation of the optical remote passive wind parameter determinator.

[0038] The outputs of the highly sensitive FPUs with signal pre-amplification units 8 of the OEM 2 are connected to the FPU signal amplifiers 11, after which they are fed to the inputs of the amplitude detectors with amplification, where the working low-frequency signals are separated, then they are fed to the inputs of the control and signal processing unit 1, and the angular sectors 9 formed by the FPU and the optical system 4 are directed to the selected area of ​​the sky 10. The optical system with variable focal length 4, the diaphragm for adjusting the radiation flux value 7, three FPUs with signal pre-amplification units 8, signal amplifiers 11 and amplitude detectors of signals with amplification 12 are installed in the housing 6 of the OEM 2.The relative positions of the photodetectors 8 and their positions relative to the optical system 4 and its optical axis make it possible to form three adjacent angular sectors 9 of the OEM 2, localized in a spatial region 10, within which the photodetectors 8 receive background radiation modulated by the moving air mass 15 from the atmosphere. The angular sectors are so spatially separated that within the spatial region 10 where they are located, the atmosphere can be considered "frozen" - having a structure that changes little over a long period of time, greater than the time of movement between the OEM sectors, which makes it possible to consider the conditions of background radiation modulation for all sectors 9 to be the same - the structure of the signals from the photodetectors 8 is repeated, with a time delay between the signals determined by the speed of movement of the air mass 15 between sectors 9.The background radiation intercepted by the optical system 4 of the OEM 2 is intensity modulated by the amplitude detector 5 and fed to the FPU 8, where it is converted into variable analog signals with a carrier frequency corresponding to the modulation frequency of the amplitude detector 5. The pre-amplified variable analog signals u1, u2, u3 from the FPU 8 are amplified (U1, U2, U3) in the amplifiers 11 and detected (U. * 1, U * 2, U * 3) in the amplitude detectors 12 with the selection of working low-frequency signals corresponding to the modulation of the background radiation by the moving atmosphere, they are converted into digital format (g1, g2, g3) in the three-channel ADC 13, and fed to the module for calculating the correlation functions Rg1g2 and R g1 g314 to determine the time delays between signals from the first and second FPU τ 12 and the first and third τ 13 FPU, proportional to the projections of the speed of movement of the air mass along the line between the first and second (V 1,2) and the lines between the first and third (V 1,3 ) angular sectors 9 of the OEM 2. Based on these projections, the speed and direction of the component of the wind velocity vector perpendicular to the optical axis of the OEM 2 are calculated. The size of the angular sectors 9, which allows obtaining information on wind parameters at different distances from the object, is changed by changing the focal length of the optical system 4 of the OEM 2 based on external control commands. Control of the position of the mechanical diaphragm 7 of the OEM 2, which ensures adjustment of the proportion of background radiation passing to the FPU 8, is carried out automatically based on the signal levels from the FPU 8.

[0039] Thus, the advantage of the proposed solution is the preservation of the sensitivity level of the process of recording background radiation modulated by moving atmospheric formations, regardless of the modulation frequency associated with their speed of movement, and, thereby, the expansion of the range of measured speeds of movement of air masses.

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