you need
• - a topographical map,
• - protractor,
• - line,
• - pencil,
• - calculator,
• - compass.
Guide
1
directional angle called angle formed by the direction of the northern central meridian (the initial direction) and the line of direction to the landmark.Directional angle is counted clockwise and is measured in the range of 0-360 degrees.
2
There are several ways of finding direction angle: with a protractor, a magnetic bearing (using a compass or a compass), a geodesic method, gyroscopic, astronomy, using hordouglomera and contour maps or aerial points.Consider some of these ways.
3
With transportiraProvedite straight line through the starting point and a reference point to the nearest vertical line on the map grid coordinates (x-axis).It is important that the distance from the starting point to the point of intersection of the line drawn with the horizontal axis is not less than the radius of the protractor.
4
Align the protractor with the x-axis: the center of the protractor to be at the point of intersection of the vertical coordinate axis and the line of the chosen direction, and the zero line of the protractor - looking north.
5
Measure angle between the vertical line grid and held the line areas: the countdown from the x-axis (north direction) - clockwise.
6
With formulas, you can go from one corner to another backsight, say, magnetic or geographic azimuth to the azimuth angle.
7
azimuth calculation using magnetic azimutaVychislite geographic azimuth.It is equal to the sum of magnetic azimuth and declination of the magnetic needle (details can be found on the map - scheme of interposition of the meridians at the bottom of the card).This amendment can be marked with "+" or "-".
8
Subtract the values ​​obtained from the geographic azimuth value of the Gaussian convergence of meridians (the value specified in the scheme of interposition of the meridians).The resulting number is the azimuth angle direction.
9
calculate the azimuth of the selected light (after extensive observations).Then calculate or determine directly from the nozzle on the compass azimuth oriented direction.When calculated by the formula directional angle .This method of determining the value of the azimuth is called astronomical.It is the most accurate.