By production of geodetic and survey works and also at explaining the ground sometimes it is necessary to determine height of the points inaccessible for direct measurement. Tops of trees, the high rock or a support of the power line can be these points. Simple make-shifts are applied to the solution of such task as special devices (for example, levels), and.
It is required to you
- - level;
- - stick or pole;
- - isosceles triangle;
- - pocket mirror.
Instruction
1. Use a level for determination of height of a remote point. It represents the geodetic tool for measurement of excess of points on a surface. There are several types of levels, but the greatest distribution was received by optical-mechanical devices. For a start study the instruction for use of the device.
2. Install the device on a support. Expose the Vizirny line of the telescope of a level horizontally by means of the built-in level. Arrange a leveling lath vertically. Guide a pipe at a lath by means of a viewfinder and an otfokusiruyta the image of a lath the corresponding adjusting screw. Make counting of height of an object on a lath, using horizontal thread of a grid as reference index.
3. In the absence of the necessary equipment use for determination of height make-shifts – a rod, a stick or a pole of the known length. On sunny day determine object height (for example, a high tree), being guided by such rule: subject height in as much times more the subject sizes with the known height how much the shadow of the measured object is more than a shadow from a stick.
4. Put a stick strictly vertically. Measure length of its shadow. Measure length of a shadow of a subject which height you want to learn. Make and solve a proportion, having cleared the bar of the measured subject as a required unknown element.
5. For application of the following method you need a student isosceles triangle. Approaching the object of measurement, establish a triangle at an eye that one its leg was directed steeply, and the hypotenuse coincided with the line of vising on a point which height you want to learn. Put distance to an object and height from the Earth's surface to your eyes; you receive height at which the required point is located.
6. It is possible to measure tree height otherwise. If near the measured object there is a usual pool, get up so that it was located between you and a subject. Now by means of a pocket mirror find reflection of top of a tree in water. Height of the top point will be in as much times more your growth how much the distance from you is up to one pool more, than distance from a pool to the observer. For measurements use the known length of the step (at the person of average height it is equal 0.7-0.8 meters).