RU2626077C1 - Method of measuring super low angular speeds - Google Patents

Abstract

FIELD: measuring equipment.

SUBSTANCE: method for measuring super low angular speeds by exciting electromagnetic waves running in opposite direction, reflecting, detecting their parameters, and calculating the value of the effective angular speed, proportional to the change in these parameters. The exciter, reflectors and detector are mounted on at least three geostationary satellites and excite electromagnetic waves.

EFFECT: increased accuracy of measuring super low angular speeds.

3 cl, 1 dwg

Description

The method of measuring ultra-small angular velocities relates to gyroscopy and can be used to measure ultra-small angular velocities in outer space.

From the works [Bychkov S.I., Lukyanov D.P., Bakalyar A.I. Laser gyroscope. Ed. prof. S.I. Bychkova. Moscow: Sov. radio, 1975. - 424 pp.] a method for measuring angular velocity using a closed resonator consisting of three or more reflectors, an exciter of two oncoming electromagnetic waves with the same frequencies (ƒ ₁ and ƒ _2, respectively) and a detector recording the same transit time of oncoming ones is known closed-loop waves in the absence of angular velocity and the difference in the propagation time of counterpropagating waves in the presence of angular velocity.

Information about the effective angular velocity Ω is distinguished by the frequency difference Δƒ = ƒ ₁ -ƒ ₂ counterpropagating waves, the value of which can be found from the following expression:

where S is the area of the closed resonator, L is the perimeter of the closed resonator, λ is the average wavelength, defined as

λ≈4πs / (ƒ ₁ + ƒ ₂ ).

It is a laser gyroscope consisting of a cathode, two anodes, three mirrors, a prism and a receiver.

Using a cathode and two anodes, two counter-running electromagnetic waves are excited with the same frequencies ƒ ₁ and ƒ _2, respectively (ƒ ₁ = ƒ ₂ ). Through a translucent mirror, both waves arrive at the receiver, where the phase shift is proportional to the angular velocity Ω.

In the absence of rotation (Ω = 0), oncoming waves have the same frequency (ƒ ₁ = ƒ ₂ ), as well as a zero phase shift between them.

When the closed resonator rotates, the frequency of one of the waves increases, and the other decreases. In this case, oncoming waves acquire additional phase shifts ϕ ₁ = arctan ξ ₁ and ϕ ₂ = arctan ξ ₂ , where ξ _{1, 2} = ± QΔƒ / ƒ is the generalized detuning of wave frequencies due to the presence of rotation, and Q is the resonator Q factor.

The value of the differential phase shift acquired by oncoming waves is ϕ ₁ -ϕ ₂ = 2arctg (QΔƒ / ƒ), or, taking QΔƒ / ƒ << 1 at small angular velocities and using expression (1), we finally obtain

,

,

where c is the speed of light.

The disadvantage of this method is the inability to measure ultra-small angular velocities due to the small perimeter of the closed resonator (about 30-40 cm).

The GEOsensor project: rotations - a new observable for seismology // Observation of the Earth System from Space. - Springer Berlin Heidelberg, 2006. - C. 427-443; Великосельцев A.A., Лукьянов Д.П., Виноградов В.И., Шрайбер К.У. Современное состояние и перспективы развития сверхбольших оптических гироскопов для применения в геодезии и сейсмологии. Квантовая электроника. 2014. Т. 44. №12. С. 1151-1156], заключающийся в размещении на поверхности Земли замкнутого резонатора с периметром 16 метров, состоящего из четырех отражателей, возбудителя двух встречнобегущих электромагнитных волн с одинаковыми частотами (ƒ₁ и ƒ₂ соответственно) и приемника, детектирующего одинаковое время прохождения встречных волн по резонатору при отсутствии угловой скорости и разность времени прохождения встречных волн при наличии угловой скорости.The closest in technical essence to this invention is a method of measuring ultra-low angular velocities, based on different travel times of counterpropagating electromagnetic waves through a closed resonator in the presence of angular velocity [Schreiber U., Igel N., Cochard A., Velikoseltsev A., Flaws A. Schuberth B., Drewitz W.,

The GEOsensor project: rotations - a new observable for seismology // Observation of the Earth System from Space. - Springer Berlin Heidelberg, 2006 .-- C. 427-443; Velikoseltsev AA, Lukyanov D.P., Vinogradov V.I., Schreiber K.U. Current status and development prospects of super-large optical gyroscopes for use in geodesy and seismology. Quantum Electronics. 2014.V. 44. No. 12. S. 1151-1156], which consists in placing on the surface of the Earth a closed resonator with a perimeter of 16 meters, consisting of four reflectors, the pathogen of two oncoming electromagnetic waves with the same frequencies (ƒ ₁ and ƒ _2, respectively) and a receiver detecting the same propagation time of the oncoming waves along the resonator in the absence of angular velocity and the difference in the propagation time of counterpropagating waves in the presence of angular velocity.

The value of the phase shift in this method depends on the size of the resonator and is proportional to the speed of rotation. Therefore, provided that the path length of the electromagnetic wave inside the resonator is known exactly, the measurement of the phase shift gives the exact value of the speed of rotation of the sensor. This phase shift is recalculated into the frequency difference of two counterpropagating electromagnetic waves in those cases when the waves propagate through the active medium of a closed resonator [G.E. Stedman. Ring-laser tests of fundamental physics and geophysics. Rep. Prog. Phys. 60, 615. 1997]. It can be written that the frequency difference of two waves

where n is the normal to the plane of propagation of electromagnetic waves; Ω is the angular velocity of rotation; K is a scale factor determined by the area S and the perimeter L of the resonator and the optical wavelength λ.

Since the observed beat frequency of two electromagnetic waves is proportional to the speed of rotation, the coefficient S determines the resolution of the measured quantity.

The ability to build resonators with a large perimeter becomes more complex and almost impossible. This is due to the fundamental limitation of the possible size of the perimeter of the closed resonator, caused on the one hand by the convergence of the longitudinal types of oscillations of the oncoming waves, and on the other by the precision manufacturing precision of the individual elements of the closed resonator.

Thus, the disadvantage of this method is the lack of accuracy of measurements of ultra-low angular velocities due to the small perimeter of the resonator.

The problem solved by the invention is to increase the accuracy of measurements of ultra-low angular velocities by increasing the perimeter of the closed resonator.

To solve the problem in the proposed method, as well as in the known one, the measurement of ultra-low angular velocities is carried out by excitation of two counter-traveling electromagnetic waves, reflection, detection of their parameters and calculation of the magnitude of the effective angular velocity proportional to the change in these parameters. But unlike the well-known pathogen, reflectors and a detector are installed on at least three geostationary satellites and excite electromagnetic waves. This becomes possible due to the propagation of electromagnetic waves in free space, while they practically do not experience interference from external disturbances.

Achievable technical result - improving the accuracy of measurements of ultra-low angular velocities.

The set of features formulated in paragraph 2 characterizes a method for measuring ultra-low angular velocities, in which the phase difference of electromagnetic waves is detected and the angular velocity is calculated by the formula

,

,

where S is the area of the contour, λ, s is the wavelength and propagation velocity of counterpropagating electromagnetic waves, respectively, Ω is the detected angular velocity.

The set of features formulated in paragraph 3 characterizes a method for measuring ultra-low angular velocities, in which the difference in the travel times of two electromagnetic waves of the perimeter of the resonator is detected and calculated by the formula

where L ₁ and L ₂ is the distance that two electromagnetic waves traveling in the resonator travel in the resonator, c is the wavelength and propagation velocity of the opposing electromagnetic waves, respectively, Ω is the detected angular velocity.

The application of the methods of claim 2 and 3 gives close accuracy and the choice of one of them will be determined by the equipment installed on the satellites.

The proposed method is illustrated by drawings, where:

in FIG. 1 - shows a General diagram of a device that implements the proposed method for measuring ultra-small angular velocity.

Consider a device that implements the proposed method (Fig. 1). It consists of three or more satellites located in the geostationary orbit of the Earth with a radius of R = 42164 km. An open closed resonator is placed on them, consisting of three or more reflectors, a bi-directional pathogen of two oncoming electromagnetic waves with the same frequencies (ƒ ₁ and ƒ _2, respectively) and a receiver (phase detector) detecting the same phase shift of the oncoming waves in a closed circuit in the absence of angular velocities and phase difference ϕ ₁ and ϕ _{2 of} counterpropagating waves in the presence of angular velocity in the form

,

,

where S is the area of the contour, λ, s is the wavelength and propagation velocity of counter-electromagnetic waves, respectively.

- расстояние между спутниками А₁ и В, которое равно расстоянию между спутниками В и С₁ (т.е. резонатор - равносторонний треугольник), а

- расстояние между спутником А₁ и точкой O₁ пересечения линии, соединяющей спутники A₁ и С₁, с высотой замкнутого резонатора h₁, имеющего треугольную форму. Периметр резонатора А₁ВС₁ будет определяться по формулеConsider the two simplest versions of a closed resonator A ₁ BC ₁ and A ₂ BC ₂ (Fig. 1) formed by three satellites (in Fig. 1 they are designated A ₁ , B, C ₁ and A ₂ , B, C _2, respectively) and having the shape of an equilateral triangle (in the general case, the shape of a closed resonator can be different). If denoted by

- the distance between the satellites A ₁ and B, which is equal to the distance between the satellites B and C ₁ (i.e., the resonator is an equilateral triangle), and

- the distance between satellite A ₁ and the point O _{1 of the} intersection of the line connecting the satellites A ₁ and C ₁ with the height of the closed resonator h ₁ having a triangular shape. The perimeter of the resonator A ₁ BC ₁ will be determined by the formula

,

,

and its area

.

.

The value of the height of the first closed resonator h ₁ can be found from the expression for a rectangular triangle O ₁ OS ₁ (Fig. 1)

,

,

where R is the radius of the geostationary orbit relative to the center of the Earth.

. Получим классическое квадратное уравнениеWhere from

. We obtain the classical quadratic equation

.

.

Solving it, we find the value of h ₁

D = (- 2 * 42146) ² -4 * 1500 ² = 7105141264-9000000 = 7096141264 (km)

,

.

,

.

,

.

,

.

Since h ₁₁ = 84318.5 km is larger than the diameter of the geostationary orbit (which cannot be), then h ₁ = 26.5 km.

(км²).Then the area of the resonator And ₁ BC ₁

(km ² ).

, которое определяется из следующего выраженияTo determine the perimeter, you need to find the value

which is determined from the following expression

.

.

км.Where from

km

Then the perimeter of the resonator A ₁ BC ₁ L ₁ = 2⋅1500.23 + 2⋅1500 = 6000.46 (km), and its scale factor will be

.

.

.For the prototype S _p = 16 m ² , L _p = 16 m and, therefore,

.

Thus, in the proposed method, in comparison with the prototype, the scale factor, and therefore the sensitivity, will increase by 6.6 times. And this is not the limit. We now consider a cavity in the form of a triangle A ₂ BC ₂ .

The scale factor for the method according to p. 2 will be

.

.

, а для высокоточного (высокоточного) -

. При этом точность измерений также зависит от выбранной дины волны: чем она больше, тем меньше точность.For comparison, as shown in [D.P. Lukyanov, V.Ya. Raspopov, Yu.V. Filatov. Applied Theory of Gyroscopes. St. Petersburg: State Research Center of the Russian Federation Concern Central Research Institute Elektropribor, 2015. - 316 pp.] K _1ϕ for a fiber-optic gyro with an average sensitivity (and hence average accuracy) is

, and for high-precision (high-precision) -

. Moreover, the measurement accuracy also depends on the selected wavelength: the larger it is, the less accuracy.

, а увеличение чувствительности в 26.7 раза.Similarly, you can determine the height of the second triangular resonator A ₂ BC ₂ h ₁₂ = 107 km, as well as its area S ₂ = 321000 (km ² ) and the perimeter L ₂ = 12003.82 km. Therefore, the scale factor for the resonator And ₂ BC ₂ will be

, and an increase in sensitivity by 26.7 times.

Thus, the description of the proposed method indicates that using the proposed method, a technical result is achieved - an increase in the accuracy of measuring ultra-small angular velocities.

Claims (7)

1. A method of measuring ultra-small angular velocities by exciting oncoming electromagnetic waves, reflection, detecting their parameters and calculating the effective angular velocity proportional to the change in these parameters, characterized in that the pathogen, reflectors and detector are installed on at least three geostationary satellites and excite electromagnetic waves. 2. The method according to p. 1, characterized in that the phase difference of the electromagnetic waves is detected and the angular velocity is calculated by the formula

where S is the area of the contour, λ, s is the wavelength and propagation velocity of counterpropagating electromagnetic waves, respectively, Ω is the detected angular velocity. 3. The method according to p. 1, characterized in that they detect the difference in travel times by two electromagnetic waves of the perimeter of the resonator and calculated by the formula

where L ₁ and L ₂ is the distance that two electromagnetic waves traveling in the resonator travel in the resonator, c is the wavelength and propagation velocity of the opposing electromagnetic waves, respectively, Ω is the detected angular velocity.

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