RU2535230C1 - High-accuracy geometrical levelling method - Google Patents

Abstract

FIELD: instrumentation.

SUBSTANCE: method consists in use of a “digital levelling unit + two bar-code rods” measuring system. A digital levelling unit has “invers” function. Lengths between toe ends on each rod are known from calibration of rods under normal conditions. Measurements involve counts as to rear and front rods. Rods are turned over and measurements are repeated. By counting from upper toe ends and having switched on “INVERS” function on the levelling unit, lengths of each rod are calculated as sums of counts obtained from two positions of the rod, and they are compared to the lengths obtained at calibration. Differences of lengths obtained at calibration and under actual conditions are corrections for temperature deviation, with a consideration of which excess values obtained at two positions of the rods are calculated. Equality to zero of calculated excess values serves as control of measurement accuracy.

EFFECT: improving accuracy of geometrical levelling.

Description

The invention relates to the field of geodesy, in particular to geometric leveling of classes I and II.

A known method of geometric leveling using dash-Invar rails, which assumes when working at the station, counts down two pairs of rails, on each of which there are two, offset relative to each other, scales and calculation of differences in excess counts between points with control of displacement along the scales of rails and differences their zeros (distances to the heel of the rack) [Instructions for leveling the I, II, III and IV classes of the SCINP (GNTA) - 03-010-02. - M.: TsNIIGAiK, 2003. - 134 p.].

A disadvantage of the known methods of geometric leveling and the leveling rails used in this case is the impossibility of taking into account the systematic temperature influence on the measurement error, since only air temperature is determined during measurements, changes in the size of the scale and the rack body, which reduce the accuracy of measurements, are not taken into account. A disadvantage of the known methods of geometric leveling using digital levels is the lack of field controls, that is, geometric conditions that allow you to control the appearance of gross errors.

The closest in technical essence are the method of high-precision geometric leveling and leveling rail for its implementation, containing two heels of rails [A.S. USSR No. 983459, MKL. G01C 15/06.1982, the "Method of high-precision geometric leveling and leveling rod for its implementation" (prototype)].

A disadvantage of the known methods of geometric leveling and the leveling rails used in this case is the impossibility of taking into account the systematic temperature influence on the measurement error, since only air temperature is determined during measurements, changes in the size of the scale and the rack body, which reduce the accuracy of measurements, are not taken into account.

The aim of the invention is to improve the accuracy of measurements with high-precision geometric leveling.

This goal is achieved by the fact that in the measuring system "digital level + two bar-code rails", having on each rail two heels located at opposite ends of the rail, when calibrating the level rails together with a digital level having the function "invers", determine the sizes between the heels of the rods (the lengths of the rods), when leveling, each rail is set alternately with the heels on its own benchmark, when calculating, the lengths of the rods in the field are determined and compared with the lengths obtained when calibrating them. The obtained length differences are taken into account in the form of corrections for the temperature deviation when calculating the excess at the station, while the zero excess obtained at two positions of the rails is used to control the accuracy of measurements at the station.

The method is implemented as follows:

- they verify a standard digital level with the function "INVERS";

- calibrate each barcode rack with two heels, determining the calibrated distance between the heels, while the second heel, strengthened at the top of the rack, like a standard heel, is connected with an invar scale, while the length of the rack Lk (calibrated), i.e. the distance from the standard (lower) heel, with the assigned zero reading, and the additional heel located in the upper part of the barcode rack, to which the maximum reading is assigned, must be precisely determined during the calibration process.

The level according to the standard method is set in the middle of the section between two pairs of reference points, horizontally, and bar codes are installed on the reference points of the section and take readings:

- “ a ” on the rear rail;

- "b" on the front rail,

calculate the excess value by the formula h = a -b.

Turn both barcode rails 180 ° and set them to the same reference points.

They include the “INVERS” function, which allows counting from the standard heel, but not from bottom to top from the benchmark, but rather from top to bottom from the top point of the staff, and take samples for each pair of barcode staffs:

- " a *" on the rear rails;

- "b *" on the front rails.

The result is a countdown on the rear and front rails:

Lzad = a + a *.;

L _lane = b + b *.

Thus, in the field, the lengths of the rails Lmeas are determined. (measured) at the actual integral temperature of the invar.

In this case, the difference ΔLt = Lmeas-Lk - is nothing more than a change in the length of each rail under the influence of temperature.

The corrections to the temperature readings will be equal to:

- Δ a = (Δ Lt ass. / Lk) × a ;

- Δ b = (Δ Lt ass. / Lk) × b;

- Δ a * = (Δ Lt ass. / Lk) × a *;

- Δ b * = (Δ Lt ass. / Lk) × b *.

The excess value h * = a * -b * is, nothing but the value of the excess h = a -b, but with the opposite sign, while, therefore, h * + h should tend to 0, which is an additional condition for measuring accuracy control.

Claims (1)

The method of high-precision geometric leveling, which consists in determining the excesses in the readings for two pairs of rails from the reference points, characterized in that each barcode rail having two heels is calibrated, determining the calibrated distance between the heels, while the second heel, fortified in the upper part of the rail, as well as a standard heel, it is connected with an invar scale, and the lengths between the heels on each rail are determined under normal conditions, when leveling, use the digital digital leveling system with the INV function ERS "+ two pairs of barcode rails", during measurements take samples on the back and front pairs of rails from the reference points, then the rails are turned over and the measurements are repeated, and the samples are taken from the upper heels of the rails, turning on the INVERS function in the level, the lengths of each rail are calculated as the sums of the readings obtained from the two positions of the rails, and compare them with the lengths obtained during calibration, the differences in lengths obtained during calibration and in real conditions are corrections for the temperature deviation, taking into account which, the excesses obtained at two positions racks, equal to zero is computed elevation control accuracy.