RU2699907C1 - Plumb line deviation detection system - Google Patents

Abstract

FIELD: instrument engineering.

SUBSTANCE: invention relates to geodetic instrument-making, in particular to systems for determining the shape of the earth, and is intended for determining deviations of the plumb line on a movable base. An absolute gravimeter is installed on the body of the antiaircraft telescope, the readings of which have been certified at the vertical position of the optical axis.

EFFECT: technical effect consists in improvement of accuracy of measurement of deviations of plumb line and reduction of requirements to gyrostabilizer, up to its exclusion from astrogeodesic complex at operation on movable base.

1 cl, 1 dwg

Description

The invention relates to the field of geodetic instrument engineering, in particular, to systems for determining the shape of the Earth and is intended to improve accuracy in determining deviations of a vertical line on a moving base.

Various devices are known for determining the VOL.

Laser meters [1]. Their disadvantage is the measurement of the deviation of the vertical line from its average area of the field work area.

Gravimeters [2]. Their disadvantage is similar, with the help of gravimeters, the deviations of the vertical line from its average over the area of the water area are measured.

Systems with a digital anti-aircraft telescope are free from this drawback [3]. They are mounted on a fixed base. A device for determining the local vertical (level, autocollimator with a liquid mirror, theodolite, etc.) is installed next to them or inside their case. As a result, at one point and at the same time determine the zenith distance of the stars in astronomical and geodetic coordinate systems. Their disadvantage is the low accuracy when working on a swinging base.

To eliminate this drawback, a ship's astrogeodesic complex (AGC) [4] was created, in which an anti-aircraft telescope with a camera and two orthogonal horizontal accelerometers rigidly mounted relative to it are placed on a platform stabilized in the horizon [5]. After double integration of the readings of the accelerometers, the increment of the installation site of the anti-aircraft telescope is determined, this increment is compared with the increment obtained from the satellite navigation system, and the FOL is calculated. The disadvantages of the complex are similar to the shortcomings [1, 2]; the AGK does not have a device for determining the astronomical vertical at the point of work. The error of the accelerometers in such a system is the main error in determining the VOL. In addition, the gyrostabilizer has significant dimensions and weight.

The objective of the invention is to improve the accuracy and mobility of the system for determining the FRA on a moving base.

This is achieved by the fact that, in contrast to the known technical solution, an absolute gravimeter is installed on the anti-aircraft telescope [6].

The technical result consists in increasing the accuracy of the VOL by an order of magnitude and reducing the requirements for the gyrostabilizer, up to its exclusion from the astrogeodesic complex when working on a moving base.

The system device is shown in the diagram. It depicts the following elements:

1 - anti-aircraft telescope,

2 - CCD matrix for measuring the angle between the direction of the star and the optical axis of the pipe,

3 - star

4 - absolute gravimeter,

5 - swing base

6 - calculator,

7 - star catalog

8 is a summing device,

9-satellite navigation system (SNA),

λ is the geodetic zenith distance of the star,

Q - steep line deviation (FOL),

q is the deviation of the direction of the star from the optical axis,

α is the deviation of the optical axis from the vertical.

The anti-aircraft telescope 1 contains a CCD matrix 2, designed to determine the angle between the optical axis of the pipe and the direction to the star 3. The telescope has an absolute gravimeter 4, designed to determine the direction of the local astronomical vertical. The telescope stands on a swinging base 5. Calculator 6 contains a star catalog 7 and an adder 8. A signal from the satellite navigation system 9 is received by the calculator. The value of the VOL in the form of the output signal of the calculator is supplied to the consumer.

When adjusting at the stand, a telescope 1 with a CCD matrix 2 is installed so that its optical axis is vertical, regardless of the position of the star 3. An absolute gravimeter 4 is installed on the telescope, and the gravimeter readings are certified, thereby fixing its position relative to the optical axis. When operating on a swinging base 5, the telescope 1 is pointed at the star. A signal for the deviation of the direction of the star from the optical axis of the telescope is formed on the CCD matrix. In this case, the gravimeter generates a signal for tilting the optical axis relative to the astronomical vertical. The signals from the CCD of the matrix and gravimeter are sent to calculator 6. In the calculator, the coordinates of the stars in the telescope’s field of vision are determined from the star catalog 7 and fed to its adder 8, where the deviation of the vertical line is determined by the difference of astronomical and geodetic zenith distances. Information about their place is received from the satellite navigation system (SNA) 9.

The FOL is measured as the difference between the zenith distances of a star in the geodetic λ _G and astronomical λ _A coordinate systems Q = λ _Г -λ _A

λ _{G is} determined by the star catalog based on information about its location received from the satellite navigation system.

λ _A = q + α is defined as the sum of the angle of deviation q of the energy center of the star from the optical axis of the anti-aircraft telescope and the deviation α of the same axis from the astronomical vertical.

The general expression of OOL is written as

Q = λ-q + α

. Энергетический центр звезд определяется на уровне Δ_q=0,01ʺ [5].The coordinates of location S using the SNA are determined with an accuracy in the linear measure Δ _S = 3 m [5], therefore, the geodetic coordinates of the stars are known with an error in the arc measure

. The energy center of stars is determined at the level Δ _q = 0.01ʺ [5].

The position of the astronomical vertical is determined using an absolute gravimeter. The gravimeter, thanks to the use of several laser beams, allows not only measuring gravity, but also the angle of inclination of the rays relative to the vertical [6]. The error Δα in determining the angle α depends on the accuracy of measuring the non-parallelism of the rays, which is determined by the error Δβ when measuring the wedge β of the dividing prism [7].

It is not difficult to produce a prism with an angle between the faces β = 3 ° and technological accuracy Δ _tech = 0.1 arc.s. [7]. During certification, the angle of divergence of rays during a one-time test can be measured [8] with a relative error of δ _β = 1.4 * 10 ^-5 and with an absolute error of Δ _ISM1 = 0.15 arc.s. With an increase in the number of tests, for example, to 100, the error with simple averaging can be reduced by an order of magnitude, and with window averaging [9] by two or three orders of magnitude, that is, to a value of Δ _meas100 = 0.01 arc.s. If the measured angle does not exceed α <6 °, and the divergence angle β = 3 °, then the error in the measurement of the angle will not exceed Δα <3Δβ = 0.03 arc.s. Therefore, within the limits of the average ship pitch θ <6 °, the anti-aircraft telescope system with an absolute gravimeter can work without a gyrostabilizer.

The technical effect consists in increasing the accuracy of measuring the VOL on a moving base and reducing the requirements for the gyrostabilizer, up to its exclusion from the anti-aircraft periscope system.

Information sources

1. Medovnikov A.S., Nigamatyanov R.M. A method for determining the deviation of a plumb line. A.S. 4801384/10 12.03.90

2. Dobrotvorsky A.N., Denesyuk E.A., Katenin V.A., Ivanov B.E. - Gravimetric method for determining the deviation of a vertical line in the ocean on a moving object. Patent No. 2348009 2007-07-02.

3. Muzarbekov M.M., Kopaev A.V., Fateev V.F. Metrological characteristics of the astrogeodesic measurement of plumb line deviations based on a digital anti-aircraft telescope. Surveying and cartography. No. 4 2016. p. 10 - 17. FSUE VNII FTRI.

4. V.A. Vasiliev, Zinenko V.N., Kogan L.B., Savik V.F., Peshekhonov V.G., Troitsky V.V., Yanushkevich V.E. Ship's astrogeodesic complex for determining steep line deviation. - “Shipbuilding industry”, series “Navigation and gyroscopy”, 1991, issue 2, p. 51-56.

5. A.N. Dziuba, L.P. Staroseltsev The concept of constructing a gyroscopic stabilization system for an anti-aircraft telescope with analytical correction of astronomical observations based on fiber-optic gyroscopes. 7th Russian multiconference on management issues. SSC RF Concern Central Research Institute Electropribor OJSC St. Petersburg 2014.

6.A.B. Popov Device for determining the vertical position. RF patent No. 2245331 dated 12/10/2013.

7. P.I. Maleev, A.B. Popov. On the issue of creating an absolute gravimeter for marine moving objects. P. 40. Navigation and hydrography, 2018, No. 51, GNIIGI St. Petersburg.

8. Sinelnikov M.I. Filippov O.K. A method for determining the angle of a glass wedge. Patent RU No. 2206870 dated 06.24.2002 Applicant and patent holder Federal State Unitary Enterprise Research Institute for Complex Testing of Optoelectronic Devices and Systems

9. http://www.dsplib.ru Window smoothing

Claims (1)

A system for determining deviations of a plumb line on a moving base, comprising an anti-aircraft telescope and a device for determining the astronomical vertical, characterized in that an absolute gravimeter is installed on the body of the anti-aircraft telescope to determine the astronomical vertical, the readings of which are certified in the vertical position of the optical axis.

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