SU1362927A1 - Method of determining frequency angle of vertical refraction - Google Patents

Abstract

The invention relates to trigonometric leveling and allows for a wider range of application and simpler method. Two theodolites, installed at different heights from the surface, simultaneously measured zenith distances from the ends of the vertical basis. At the height of the lower theodolite, air temperature and pressure are determined to determine normal refraction. Triangulation or distance metrics determine the distance to the observed target. The obtained values of the difference of refractions, equivalent heights and the angle of normal refraction are used to calculate the partial refraction angles. 1 il. i SL 00 SP) yu

Description

1362927 2

The invention relates to geodesy, the retick zenith distance will be

are equal, and the angle p is zero. When using different vertical bases, it is necessary to introduce corrections for their difference. Placing observations on an equal vertical basis, to determine refraction, does not require measuring the distances S, and Sg, to the target. The system of equations for vertical refractions for different heights of a single point appears as follows:

ten

mainly for trigonometric zooming, and can be used to determine the angle of vertical refraction in triangulation cases, in determining the heights of inaccessible targets, passing elevations through water obstacles, determining heights in seismically dangerous areas, determining the refractive index and structural characteristics of the atmosphere, for optical radiation.

The aim of the invention is to expand the field of application and simplify the method.

The drawing shows a scheme for implementing the method.

The essence of the method is as follows.

When observing the zenith distance at one point from two heights (see drawing), it is possible to determine the difference of vertical refractions at a point. For this purpose, it is necessary to measure the distances Sj and S to the observable target and the vertical basis b (the transition between the heights of the instruments), after which the angle is determined which is 30

the theoretical value of the zenith distance Z ° and Z °. The angle is determined by the limestone trigonometry formulas.

 g. Sln z

where S, and S, are the measured distances to

or

Z, and Z, and z;

b is the vertical basis. The difference in vertical refractions is determined by the following formula:

45

5 uS-1 4-8,

2., 1 -q t

where q is h, ii

91

targets, respectively, from the upper and lower observation points; measured zenith distances at appropriate altitudes; theoretical values Thus, the partial angle of the vertical distances for 50 times the tical refraction can be semi-appropriate heights; without gradient temperature measurements on the track. In favorable conditions, i.e. during periods of calm images and increasing

U & SZ, -SZ. (Z, -Zj,).

(2)

When observed on the same vertical basis at another point, the theoretical zenith distance will be

are equal, and the angle p is zero. When using different vertical bases, it is necessary to introduce corrections for their difference. Placing observations on an equal vertical basis, to determine refraction, does not require measuring the distances S, and Sg, to the target. The system of equations for vertical refractions for different heights of a single point appears as follows:

SZ, S, -i-334.35J

 G., & „+ 334-35

D5 - „

Sj

3 g

T R,

The solution of this system makes it possible to determine the partial angle of refraction:

". :: 7G7G

 n

or

g. + S.

91- h ,,

S ,.

s

(four)

those

(one)

With a large distance

35 tends to unity therefore under the assumption that S, S we write

6 „lg 2.1

192

0

E1. h:

or

five

S.-D5

2. 1

5 uS-1 4-8,

2., 1 -q t

(five)

where q is h, ii

91

Thus, the partial angle of the vertical refraction can be obtained without performing gradient measurements of the temperatures on the track. In favorable conditions, i.e. during periods of calm images and increasing

55, the measurement accuracy of the refraction difference is up to 1, the accuracy of the method is 3-5.

Measurements can be made from a geodetic signal and from a tripod.

located on the same vertical as possible. Special buildings and sometimes steep terrain can also be used for observations.

The method is carried out as follows.

Install two high-precision theodolite type G 1, T 0.5, OT-02, etc., at different heights from the underlying surface. One set on the table signalp (top), the other. on a tripod above the center of the mark (below), and simultaneous measurements of the zenith distance are taken. 7 (l to increase the accuracy of the measurement method should be made by 6-10 methods. Measurement of meteorological air parameters at the height of the lower instrument, temperature T and pressure P to measure the normal refraction using the formula (1), determine the distance to the observed target using triangulation or ranging methods and measure the vertical basis. Calculate equivalent heights using a map or path profile. Vertical refraction differences are calculated from the averaged values of the measured zenith distances at different heights over Formula (2). Knowing the difference of refractions, equivalent heights and the angle of normal refraction, calculate the partial angles of refraction using the formula (5). When observing an equal vertical basis at another point, to determine the particular angle of refraction, knowledge of linear distances to Item optional.

Claims (1)

Invention Formula The method for determining the partial angle of vertical refraction, which consists in measuring the distance to the target, meteorological parameters at a point, observation, synchronous measurement of zenith distance, and a computational institute of equivalent heights, characterized in that in order to expand the area of application and simplify the method, measure zenithal distances are produced from the ends of the vertical basis located at the observation point, after which the partial angle of refraction is calculated. INSIDE Order 6354/26 Random polygons pr-tie, Uzhgorod, st. Project, 4 Circulation 677 Subscription