In the field activities, such as geological investigation, mountaineering, hiking, exploration, tourism, etc., in order to prevent from getting lost, correctly determine the location and direction, must master the positioning and lateral method.In nature, some animals have the instinct of direction discrimination, such as pigeons, and some members of human beings also have this ability, but most people do not have or only have this latent ability, so the determination of direction in the field mainly relies on experience and tools.
There are many ways to determine the direction and position in the field.
Use a compass
Place the compass or compass needle horizontally so that the bubble is centered. When the needle is stationary, the black end marked “N” indicates north.Besides measure due north direction, compass or ones can also detect a target’s exact position, method is to open a compass will diopter aim, or aim the dial 0 on the calibration target, target, zero calibration and magnetic point in a straight line, compass levels still, n-terminal refers to scale is the survey points to the target location, such as needle to 36 ° N end.Then the target is 36° north by east of the measuring position.
Using a compass or compass to determine direction is simple and fast, but it requires attention: 1. Try to keep level; 2.2, do not get too close to the magnetic material;3. Do not mistake the S end of the magnetic needle for the north to make a direction error of 180°;4. Master the magnetic deviation Angle of the active area for correction.
Using the sun
On a clear day, east and west can be easily known and judged according to the rising and setting of the sun. However, only a rough estimate can be made.1, watches direction finding “hours binary to the sun, 12 refers to the north”, typically between 9 to 4:00 in the morning can quickly identify the direction, in half the time the direction of referring to the sun, is time 12 degrees north, such as 40 time in the afternoon, the half is transformed, put on to the sun, then 12 refers to the north, or is to put the table laid, hour hand points at the sun, the hour hand and 12 time degrees bisector of reverse extend direction is the north;Or set the watch, a small stick vertically standing in the middle of the watch to rotate the watch, so that the shadow of the small stick and the hour hand coincide, the bisector between the hour hand and 12 degrees is north.
Attention must be paid to :(1) to determine the direction, the watch should be flat;(2) it is not suitable to use around noon in the area between 20°30 ‘north latitude and south latitude. That is to say, the standard longitude line shall prevail. Every 15° east plus 1 hour, and every 15° west minus 1 hour.2. The direction of the shadow is clear, and a stick is erected on the ground. The shadow of the stick moves with the change of the position of the sun.Draw a series of concentric circles on a drawing paper of 50×50cm. The radius of concentric circles increases by 1cm. Nail them to a flat plate and fix them horizontally.When the position of the sun changes, the end points of the shadow will always intersect with the concentric circle. Plot these points, and then connect the two straight points on the same circle with the center of the circle.
The stars at night
At night, the north star and the southern cross can be used to determine direction.
1. Polaris: Polaris is located in the due north sky, and its exposed height Angle is equivalent to the local latitude. Therefore, Polaris can be quickly found.Usually based on the big dipper (Ursa major) or W (queen of the celestial constellations).The big dipper is seven bright stars shaped like a spoon, and extending the first two betas to alpha by about five times is the north star.When you can’t see the big dipper, you can look for the north star according to the W star, that is, the constellation after the fairy.The constellation Cepheus is made up of five bright stars, shaped like the “W” letter, and the opening direction of the letter is about twice the width of the opening is the north star.
2. Southern cross: south of latitude 23°30 ‘, southern cross can sometimes be seen at night, consisting of four brighter stars, shaped like the word “ten”, in the lower right, from gamma to alpha two stars four and a half times the length of the line (without stars) is due south.
Features of landscape and plants
Sometimes a few features and plant growth in the field are good indicators of direction, and adding this knowledge can help you quickly identify directions.
A. Houses: generally open to the south, especially in the north of China;
B. Temples: usually open to the south as well, especially the main building in the temple cluster;
C. prominent: brophytes that are moist at base and may grow low on the north side.
2. Plant growth characteristics:
A. generally on shaded slopes, i.e. on the northern slopes, low ferns and vines are more developed than on sunny slopes.
B. Individual plants have more foliage on the sunny side, and moss may grow on the trunk in the shade on the north.
C. tree rings can be seen clearly on the transect of the trunk of many trees in the north of China, with sparse rings on the south side and compact rings on the north side.