In the field activities, such as geological investigation, mountaineering, hiking, exploration, tourism, etc., in order to prevent getting lost and correctly determine the location and direction, it is necessary to master the positioning and lateral methods. In nature, some animals have the instinct of discerning direction, such as pigeons. Some members of human beings also have this ability, but most people do not have or only have this potential. Therefore, the determination of direction in the wild mainly depends on experience and tools.
There are many methods to determine direction and position in the field. Here are several common methods.
Use compass
Place the compass or compass horizontally to center the bubble. When the magnetic needle is still, the black end marked "n" refers to the north. In addition to measuring the true north outward, the compass or compass can also measure the specific orientation of a certain target. The method is to open the compass to align the collimator with the target, or to align the scale 0 on the dial with the target, so that the target, scale 0 and magnetic center point are in the same straight line. After the compass is horizontal and stationary, the scale at the N-end refers to the orientation from the measuring point to the target, such as the magnetic needle N-end points to 36 °. Then the target is 36 ° NBE of the measurement position.
Although it is simple and quick to use compass or compass to identify the direction, we need to pay attention to: 1. Try to keep the level; 2. Don't get too close to the magnetic material; 3. Don't mistake the s end of the magnetic needle for the north to create a 180 ° direction error; 4. Master the magnetic declination of the active area for correction.
Use the sun
In a clear day, we can easily know the East and the West according to sunrise and sunset, and we can also judge the square, but it can only be roughly estimated. There are several methods for more accurate measurement: 1. Watch direction finding "half of the hour is to the sun, and 12 is to the north". Generally from 9 a.m. to 4 p.m., we can quickly identify the direction, and use half of the time to refer to the square To the opposite sun, 12 degrees is the north. For example, at 14:40 p.m., half of it is 7:20. Turn the clock to the sun, then 12 points to the north, or put the watch flat, and the clock points to the sun, and the reverse extension direction of the bisector between the clock and 12 degrees is the north; or put the watch, and stand a small stick vertically in the center of the watch, and turn the watch to make the shadow of the small stick and When the clock coincides, the bisector between the clock and 12 degrees is the north.
It must be noted that: (1) when judging the direction, the watch should be placed horizontally; (2) it should not be used before or after noon in the area between 20 ° 30 'south latitude and north latitude, that is to say, the longitude of the standard time shall prevail, 15 ° East plus 1 hour, 15 ° West minus 1 hour. 2. The direction finding of the sun shadow is sunny. A stick is erected on the ground. The shadow of the stick moves with the change of the sun's position. These shadows are the shortest at noon. The line at the end of the stick is a straight line. The vertical line of the straight line is north-south direction. Draw a series of concentric circles on a 50 × 50cm drawing paper. The radius of the concentric circles increases by 1cm. Nail them on the plate and fix them horizontally. Insert a 12-15cm long fine steel needle or needle into the center of the circle vertically. When the position of the sun changes, the end points of the shadow always intersect with the concentric circle, mark these points, and then connect the two points on the same circle in a straight line, and connect the midpoint of these lines with the center of the circle. This line is the north-south direction line, and the direction of the top of the arc is the north.
Night stars
At night, you can judge the direction according to Polaris and Southern Cross.
1. Polaris: Polaris is located in the north sky, and its exposed altitude angle is equivalent to the local latitude, so Polaris can be found soon. It is usually determined by the Big Dipper (Ursa Major) or the w (Andromeda). The Big Dipper is seven brighter stars in the shape of a spoon. Connecting the two β's on the tip of the spoon to α and extending about 5 times is Polaris. When you can't see the Big Dipper, you can look for Polaris according to the w star, the constellation of Andromeda. The constellation of Andromeda consists of five brighter stars, which are shaped like the "W" letter. The opening direction of the letter is about twice the width of the opening, and Polaris is at the distance.
2. Southern Cross Star: in the area south of 23 ° 30 'north latitude, the Southern Cross Star is sometimes seen at night. It is composed of four bright stars, which is similar to the character "ten". In the lower right part of the star, the four and a half times of the connecting length of the two stars from γ to α (no star) is in the south direction.
Features of features and plants
Sometimes some features and plant growth characteristics in the wild are good direction signs. Increasing this knowledge can help you quickly identify the direction.
1. Features:
A. houses: generally, the doors open to the south, especially in the north of China;
B. Temple: it is usually open to the south, especially the main building in the temple complex;
C. protruding features: bryophytes that are wet at the base of the north side and may grow low.
2. Plant growth characteristics:
A. on the general shady slope, i.e. the northern hillside, low ferns and lianas are more developed than those on the sunny side.
B. the sunny side of a single plant has more luxuriant branches and leaves, while the shady trunk to the North may grow bryophytes.
C. in the north of China, there are clear rings on the cross section of tree trunks, which are sparse on the south side and close on the north side.

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