SU757847A1 - Method of simultaneous determining of geographical coordinates and true meridian direction - Google Patents

Description

The invention relates to geodetic astronomy and can be used for topographic surveys, engineering surveys of linear objects and navigation. ³

Known methods for determining the geographical coordinates and directions of the true meridian from the measured zenith distances of two stars [1]. . To determine the latitude and longitude ^{υ in} this way, it is necessary to observe three stars at the moments of their equal heights and for these moments their coordinates must be known, and the meridian direction must be found 15 separately.

There is also a method of jointly determining the latitude, adjusting the clock and azimuth from separate observations of 20 two stars using a theodolite, which consists in measuring zenith distances at the moment of passage of the selected two stars through one common vert, cal and calculating the desired values [2]. ³

The disadvantage of this method is large. duration, since the period of time between the passage of stars through a common vertical can be large.

The purpose of the invention is to increase the efficiency of the method.

This goal is achieved by the fact that in the known method for jointly determining the geographical coordinates and direction of the true meridian, including observing the luminaries using a nozzle on a pipe of a geodetic instrument, for example, a theodolite, a nozzle made of two mirrors rigidly mounted on a movable base with a turntable under angles to the optical axis of the pipe of the geodetic instrument, respectively equal to half the polar distances of two pre-selected stars for observations, with by a multiple rotation of the reflecting planes of the mirrors at an angle equal to the difference in the hour angles of the stars, the geodetic instrument pipe is pointed at an arbitrarily selected terrain point, then by rotating the instrument on the horizontal and vertical planes and the moving part of the nozzle around the axis of the turntable, the rays from both observed stars are combined in the focal plane of the pipe on the optical axis, fix the time at the time of alignment and take counts in the circles of the theodolite and nozzles, which are used to judge the geographical coordinates and direction of meridian.

In FIG. 1 shows a longitudinal section through a nozzle with a pipe; FIG. 2, too, top view; in FIG. 3 is the same side view.

The fixed part of the nozzle 1 is attached to the objective ring 2 of the theodolite pipe. It consists of a mounting device (not shown in the drawing), a reference index or scale 3, a limb microscope 4 and a cylindrical level 5, which is designed to install the index on a vertical plane passing through the optical axis of the pipe and to orient the fixed part of the nozzle on the pipe. The movable part consists of a board 6, a turntable 7, and two flat mirrors 8 and 9. Mirrors along line 10 divide the entrance pupil of the lens into two parts. The axis of rotation of the board, circle and mirrors coincides with the optical axis of the pipe. The reflecting planes of the mirrors are tilted to the theodolite lens. Mirrors in the plane of the drawing (FIG. 2) are rotated at an angle equal to the difference of the sentries and the angles of the observed stars. The angles between the reflecting surfaces of the mirrors and the board are equal, respectively, to an angle of 90 ° minus half the polar distance of the observed star.

The geographic coordinates — latitude Φ, longitude 7 \ and the direction of the true meridian are found from the positions of the selected two stars in their diurnal revolution around the axis of the world. To make observation possible at any time on a stellar day, non-stop stars are chosen, for example, for northern latitudes from 40 ° and higher (5 “Cassiopeia” and the bucket “Ursa Major”).

Before work, the nozzle is mounted on a theodolite. For this theodolite; set at a distance of 15-20 m 'from a plumb line' with a length of 5-7 m _to Achieve the vertical thread of the theodolite pipe grid to be directed along a plumb line, then attach the nozzle to the lens and rotate it until index 3 or zero of the dial scale the microscope will not descend when plumbing the pipe. Next, the zero of the nozzle turntable is combined with index 3, the theodolite is rotated 180 ° and, observing through a mirror coupled with the zero of the turntable, it is ascertained that the plumb line is aligned with the vertical thread of the theodolite pipe grid.

Having established a theodolite with a nozzle above the standing point, the pipe is pointed at an arbitrarily selected azimuthal point of terrain K. By rotating the tool in the horizontal and vertical planes and the moving part of the nozzle around the axis of the turntable, the rays from both observed stars and the focal plane of the pipe are aligned on the optical axis.

With this position of the combined image of the stars, the target axis of the theodolite will be directed to the pole of the world of the past, selected time.

It is known that the pole of the world is continuous, but moves along the longitude of the ecliptic at a speed of P = 54 ’6 3 during the tropical year, and the angle between the planes of the ecliptic and the equator is equal to £.

Having chosen the past point in time, for example, the beginning of the 1930 tropical year and orienting the device, as mentioned above, they achieve that the target axis of the theodolite is directed to the point of space (Ρ _ηο ) _ί ι · which at the beginning of the 1930 tropical year was the pole of the world.

At this moment, Moscow time νπ _Μ η is recorded ^and the following four angles are measured: - zenith distance of the point (P _then ) 1; A _and s are the horizontal angle between the directions to an arbitrarily chosen azimuthal point of the terrain K and the point (P _by ) f; - the angle in the plane perpendicular to the optical axis between the directions to the zenith point Ζ and one of the observed stars, for example, the hourly angle of the same star at stellar midnight relative to the selected point in time.

The first angle is measured with the vertical circle of the theodolite, the second with the horizontal circle of the theodolite, the third with the turning circle of the nozzle, and the fourth · used as a constant value.

The desired values are calculated by the following formulas:

βΐ η = εοδΖ ^ οοδ ^ ΡΤεΑηε) + δΐπΖ ^ · 5'ιπ (ΡΤ5ϊηε) χ ^хс ° 5 ("'Ло);

where A ^ is the land in the horizontal plane between the direction to an arbitrarily selected point of terrain K and the direction of the true meridian;

T is the period equal to the difference between the observation time and the selected time instant • ^where

B is the hourly angle of the point (P _in ) 1;,

- stellar time of the prime meridian.

The hourly angle of 1 point '· (P _Po is determined by ΐ' depending on the beginning of the stellar day to the time of observation.

Stellar day is divided into four equal parts. If the measurement is carried out in, then ΐ = ΐ - 90 °} in the first quarter, the second -1 ~ 270 ί = 270 - 1 '}

V + 1 'where ΐ; in the third in the fourth - ί = 270 + is determined from the relation.-Α _ν ).

Star time of a zero meridian of 6 _g is determined from the ratio

b) _{k |}

Ap ^ ^{+ P} with ^zt5b * ^{5b +} md where

- stellar time of the beginning of the day of the closest date to the time of observation, for which 15 this time is known;

P _s - the number of whole days expiring from 01б§- to the beginning of the day of the date of the emb people; twenty

З ^т 56 ⁵ , 56 - time for which the sidereal day is shorter than the average sunny day;

To -. a transition coefficient of 25 from average solar to stellar time, equal to 1.002738.

The proposed method allows to find the geographical coordinates and βθ direction of the true meridian faster and easier / than by known methods due to the simultaneous observation of celestial bodies.

Claims (1)

The claims A method for jointly determining the geographic coordinates and direction of the true meridian, including observing luminaries using a notch on the pipe of a geodetic instrument, for example, a different heme, which, in order to increase the efficiency of the method, use a nozzle made of two mirrors rigidly mounted on a movable base with a turntable at an angle to the optical axis of the pipe of the geodetic instrument, respectively equal to half the polar distances of two stars preselected for observation, with imnym steer reflecting planes at an angle equal to the difference in time 'angles stars suggest' geodesic instrument tube on an arbitrarily selected ground point, and then the tool rotating in the horizontal and vertical. the planes and the moving part of the nozzle around the turntable combine the rays from both observed stars in the focal plane of the tube on the optical axis, record the time at the moment of alignment and take counts in the circles of the theodolite and nozzle, which are used to judge the geographical coordinates and direction of the true meridian.