SU1485014A1 - Device for determining refraction variations - Google Patents

Description

The invention relates to means for determining atmospheric refraction and its

2

components in the surface layer of air. The aim of the invention is to improve the accuracy of measurements and expansion of functionality due to the additional, determining changes in horizontal refraction. The device consists of a telescopic system of 3, 4, 5, 8, 9, 10, 20, 21, a node for shifting the sighting beam with a micrometric screw 12 and a sighting target. The node of displacement of the sighting beam is made with the possibility of installation in a horizontal vertical plane. The element of the telescopic system 10 is made in the form of a rectangular prism with a roof on the hypotenuse edge. 7 il.

figure 1

1485014

The invention relates to the determination of atmospheric refraction when sighted by a geodetic instrument and can be used to measure the components of refraction in the surface layer of air.

The purpose of the invention is to expand the functionality of the device in order to measure in the process of surveying geodetic surveys not only vertical, but also the horizontal components of atmospheric refraction, as well as improving the accuracy of determinations.

FIG. 1 shows a schematic diagram of the device, a projection on a vertical plane; in fig. 2 is a view A of FIG. I, with the vertical position of the refracting face of the plate; in fig. 3 - the same, with the horizontal position of the refractive edge; in fig. 4 - palette with groups of paired strokes; in fig. 5 is a diagram of the action of the liquid compensator; in fig. 6 - the course of the rays in a rectangular prism with a roof on the hypotenuse edge; in fig. 7 is a diagram of the action of an optical wedge reinforced in front of a plane-parallel micrometer plate.

The device consists of lifting screws 1, stand 2, focusing lens 3, mesh 4 threads, eyepiece 5, installation level 6, body 7, ampoules 8 and 9 with compensator fluid, rectangular prism with roof 10, magnifier 11, 12 micrometer drum with scale , thrust 13, the holder 14, the frame 15, the plane-parallel plate 16, the optical wedge'17, the bearing 18, the latch 19, the lens 20 and the mirror 21. The palette contains horizontally 22 and vertically 23 oriented strokes.

The telescopic system of the broken-type device includes an eyepiece 5, a grid of 4 filaments, a focusing lens 3, a mirror 21, a lens 20, a liquid compensator 8, 9 and an output rectangular prism 10 with a roof on the hypotenuse face. The yoke 14 is made rotatable relative to the housing 7, the rotation is carried out on the bearing 18 around the optical axis of the telescopic system BP, the latch 19 locks the position of the yoke 14. The plate 16, the optical wedge 17 in the frame 15. The thrust 13, the drum 12 and the magnifier 11 constitute a micrometer that turns together with the clip 14 relative to the housing 7 around the axis BP. The inclination of the frame 15 relative to the holder 14 is carried out around the axis of the core rotation of the drum 12. The plane-parallel plate 16 and the wedge 17 are installed within half of the light hole of the lens. The palette allows you to count both horizontal and vertical components of the refraction.

The process of measuring the components of refraction consists in sighting on a pallet installed in a fixed position away from the device and rotating the drum 12 micrometers. Accordingly, the bezel 13 inclines the rim 15 of the plane-parallel plate 16 and the wedge 17 around the axis C £>. The plate 16 and the wedge 17 displace the image within half of the light hole of the objective 20, the doubling and mutual movement of images of wedge-shaped and straight lines of the pallet are observed in the eyepiece of the telescopic system. The moment of coincidence of the straight line with the wedge-shaped bisectrix is recorded by reading on a 12-micrometer drum scale. This count corresponds to the magnitude of the component of refraction. Measurement of the vertical component of refraction is performed by combining the strokes a and b of the group 22 of the pallet, the latch 19 is in the lower position (Fig. 2). Measurement of the horizontal component of refraction is made by combining the strokes with and ά of the group 23 of the pallet, to which the position of the latches 19 corresponds (Fig. 3).

When the device is tilted at a small angle ε, the liquid in ampoules 8 and 9 (Fig. 5) forms two liquid wedges with a refractive angle ε, the refractive index of the liquid is chosen to be 1.5000. He. ·, N. Cue wedge deflects the beam to its base at an angle

ω = θ (η — 1), (1)

where θ is the refracting angle of the wedge;

n is the refractive index of the material

from which the wedge is made.

Two liquid wedges in accordance with the expression (I) deflect the beam, directed normally to the plane of the bottom of the ampoules, by an angle (Fig. 5)

ω = 2ε (1 · 500-1) = ε.

Select the spatial coordinate system ΟΧΥΖ (Fig. 6) so that the axis ΟΖ coincides with the optical axis of the system, and the axis ΟΥ is in the main plane of the output prism 10. Then the normal vector of the liquid surface in ampoules 8 and 9 of the compensator (vector of the zenith direction) is in a vertical plane passing through the axis ΟΖ. Following the intersection of this vertical plane with the plane ΧΟΥ there is a line component with the axis OX angle φ.

The components of the unit vector of the surface normal of the liquid N along the three coordinate axes are as follows:

N —είπε · СО8 ^ \

—Είπε- 5ίηφ; (2)

Ν ^ —βοε.

Since the unit vector of the beam coming out of the compensator is complanar to vector Ν, its equation is

A = A _x 1 - \ - Ay / -} - A ₂ k, (3)

five

1485014

/

where Л _х = 5ш-со5 <р;

Ay = 81pg- $ 1plr; (four)

Ah = so8e ,.

When a ray of light falls on the edge of the roof 5 of the output prism 10 at point B, total internal reflection occurs. The equation of a unit vector of a roof edge, having a 45 ° angle of inclination to the OS axis, has the form

(5) ¹⁰

Then the equation of the unit vector of the ray after reflection at a point can be found from the expression

______ 15

A = -A '+ 2P (PA'). (6)

Substituting (3) and (5) into (6), after transformations, we obtain

(7) 20

The proof of the horizontal position of the reflected beam vector is its perpendicularity to the unit normal vector to the liquid surface Ν. Under this condition, the scalar 25 product of vectors should vanish, i.e.

(/ U-L *) = O. (eight)

The condition of horizontality of the component Lh of the vector of the reflected beam L ", which ensures the strict orientation of the horizontal component of refraction, has the form

Lx = ^ _x (9)

Substitution (2) and (4) in the formula (8) receive

(Ν Α *) - 8Ϊ.η ² ΐ, · ω8 ² y. (ten)

Since the magnitude of the angle e is approximately 10''to, for any values of the angle φ, condition (8) is satisfied with an error of no more than 0.6 · 10 ^_6 . Condition (9) becomes identity. Since the components of L? and A _x are equal in size and have opposite signs, the image of the palette in the telescope is stabilized both vertically and horizontally, which ensures high accuracy of measurement of the components of the refraction increments.

Claims (1)

Claim A device for determining changes in refraction, containing successively located telescopic system, a node for shifting the sighting beam with a micrometer and a sighting target, characterized in that, in order to improve accuracy and enhance functionality due to the additional determination of changes in horizontal refraction, it is equipped with an optical wedge located after the node of the bias of the sighting beam, made with the possibility of translation into the horizontal plane, the optical wedge is rigidly connected with the node of the bias of the sight beam, and the telescopic system is made with a liquid compensator, the output of which has an inserted roof-shaped rectangular prism. view A 1485014 'FIG. 7