Determination of distances and hearing of sounds on the ground and target designation
All benefits for traveling: tourists, hunters - always a great place is given to methods of determining distances to any objects without the help of special tools. Of course, skill is not out of place. I think, however, that when preparing to cross the river, you will lose a little if you determine its width of 75 meters, although in fact it is equal to 120 meters. Well, you’ll have to row a few minutes longer - which will change. It is much more important to be able to determine not the width of the crossing, but find a place that is good for her, find out the depth and nature of the ford (see below). For a hunter, it is important to know the exact distance, for example, to a moose lying in the snow, in order to correctly take out the front sight and get the beast with one shot. This is achieved not only by great practice, but also with the help of special techniques and devices, which in turn help this practice itself.
It is often necessary to determine the distance to various objects on the ground, as well as assess their size. The most accurate and fast distances are determined by means of special instruments (range finders) and rangefinder scales of binoculars, stereo tubes, and sights. But due to the lack of devices, distances are often determined with the help of available tools and by eye.
Among the simplest methods for determining the distance (distance) to objects on the ground are the following:
- by eye;
- according to the linear dimensions of the objects;
- visibility (distinguishability) of objects;
- on the angular size of known items;
- by sound, etc.
Eye to eye
Osemer - this is the easiest and fastest way. The main thing in it is the training of visual memory and the ability to mentally set aside well-represented permanent measure on the ground (50, 100, 200, 500 meters). Having fixed these standards in memory, it is easy to compare with them and estimate the distances on the ground. Click here for an example of using the eye method for determining distances in pictures .
When measuring the distance by successive mental postponement of a well-studied constant measure, it must be remembered that the terrain and local objects appear reduced in accordance with their distance, that is, when removed twice and the object will appear twice as small.
Therefore, when measuring distances, the mentally deferred segments (terrain measures) will decrease according to the distance.
It should take into account the following:
- the closer the distance, the clearer and sharper the visible object seems to us;
- the closer the subject, the more it seems;
- larger objects appear closer than smaller objects at the same distance;
- a brighter object appears closer than a dark colored object;
- brightly lit objects appear closer to dimly lit, located at the same distance;
- during fog, rain, at twilight, cloudy days, when the air is saturated with dust, the observed objects appear farther than on clear and sunny days;
- the sharper the difference in the color of the object and the background on which it is visible, the more reduced the distances seem to be; so, for example, in winter, a snow field seems to bring darker objects on it;
- objects on flat terrain appear closer than on hilly, distances that are determined through extensive bodies of water seem particularly reduced;
- folds of the terrain (river valleys, depressions, ravines), invisible or not fully visible by the observer, hide the distance;
- when lying down, objects appear closer than when standing;
- when viewed from the bottom up - from the bottom of the mountain to the top, objects appear closer, and when viewed from top to bottom - further;
- when the sun is behind us, the distance is hidden, shining in the eyes - it seems larger than it really is;
- the smaller objects in the area under consideration (when viewed through water, a flat meadow, steppe, arable land), the distances appear to be smaller.
The accuracy of the eye is dependent on the person's training.
For a distance of 1000 m, the usual error ranges from 10-20%.
By linear dimensions
Determination of distances by the linear dimensions of the object (subject)
Determination of distances by linear dimensions of objects is as follows (Fig. 9). Using a ruler located at a distance of 50 cm from the eye, the height (width) of the observed object is measured in millimeters. Then the actual height (width) of the object in centimeters is divided by the measured by the ruler in millimeters, the result is multiplied by a constant number 5 and get the desired height of the object in meters .
For example, the distance between telegraph poles of 50 m (Fig. 8) is closed on a ruler with a 10 mm segment. Therefore, the distance to the telegraph line is equal to:
The accuracy of determining distances by angular and linear values is 5-10% of the length of the measured distance. To determine the distances from the angular and linear dimensions of objects, it is recommended to remember the values (width, height, length) of some of them, given in the table below.
|Medium tank||2-2.5||6-7||3-3 5|
|Armored personnel carrier||2||5-6||2-2,4|
|Motorcycle with a sidecar||one||2||1.2|
|Four-wheel passenger car||four||20||3|
|Four-axle railway tank||3||9||2.8|
|Wooden post line||5-7||-||-|
|Man of medium height||1.7||-||-|
To determine the distance in this way, you need:
- keep a ruler in front of you at arm's length (50-60 cm from the eye) and measure, in millimeters, the width or height of the object to which you want to determine the distance;
- The real height (width) of the object, expressed in centimeters, divided by the apparent height (width) in millimeters, and the result multiplied by 6 (a fixed number), we get the distance.
For example, if a pillar with a height of 4 m (400 cm) is closed along a ruler of 8 mm, then the distance to it will be 400 x 6 = 2400; 2400: 8 = 300 m (actual distance).
To determine distances in this way, it is required to know well the linear dimensions of various objects, or to have this data at hand (on a tablet, in a notebook). The dimensions of the most frequently encountered objects must be remembered by man, since they are also required for the method of measurement by the angular value, which is basic for us.
By visibility (distinguishability) of objects
To the naked eye, one can approximately determine the distance to the targets (objects) by the degree of their visibility. For example, if someone saw a pipe on the roof of a house, it means that there is no more than 3 km to the house, and not exactly 3 km. A soldier with normal visual acuity can see and distinguish certain objects from the following distance limits shown in the table below:
|Objects and signs||
Distances from which they
|Separate small house, izba||5 km|
|Chimney on the roof||3 km|
|Aircraft on the ground tank in place||1 2 km|
|Trunks of trees, kilometer poles and poles of the communication line||1.0 km|
|Movement of the legs and arms of a person running or walking||700 m|
|Machine gun, mortar, anti-tank gun, stakes wire obstacles||500 m|
|Light machine gun, rifle, color and parts of clothes on a person, oval of his face||250 - 300 m|
|Roof tiles, tree leaves, wire on stakes||200 m|
|Buttons and buckles, details of the weapons of the soldier||100 m|
|Human facial features, hands, details of small arms||100 m|
It should be borne in mind that the table shows the limiting distances from which certain objects begin to be visible. For example, if a soldier saw a pipe on the roof of a house, then this means that there is no more than 3 km to the house, and not exactly 3 km. It is not recommended to use this table as reference. Each soldier must individually clarify these data.
When eyeing the distances, it is desirable to use landmarks, the distances to which are already accurately known.
By angular value
Determination of distances from the angular size of the object (subject)
Determination of distances from the angular size of objects based on the relationship between angular and linear quantities. The angular sizes of objects are measured in the thousandth with the help of binoculars, observation and aiming devices, rulers, etc. To use this method, you need to know the linear value of the observed object (its height, length or width) and that angle (in thousandths) under which this object is visible.
For example, the height of the railway booth is 4 meters, the person sees it at an angle of 25 thousandths (the thickness of the little finger).
Then the distance to the booth will be 4 x 1000 = 4000 divided by 25, that is 160 meters.
To determine the angular value, you need to know that a segment of 1 mm, 50 cm from the eye, corresponds to an angle of two thousandths (written: 0-02).
From here it is easy to determine the angular value for any segments. For example, for a segment of 0.5 cm, the angular value will be 10 thousandths (0-10), for a segment of 1 cm - 20 thousandths (0-20), etc.
The easiest way to memorize standard values are thousandths:
|Item Name||Size in thousandths|
|Index finger thickness||33|
|Middle finger thickness||35|
|Cartridge width Dults sleeve (7.62 mm)||12|
|Sleeve 7.62 mm wide||18|
The distance to objects in meters is determined by the formula: where B is the height (width) of the object in meters; Y - the angular value of the object in thousandths.
- The angular size of the landmark observed in binoculars (a telegraph pole with a support), whose height is 6 m, is equal to the small division of the binocular grid (0-05). Therefore, the distance to the landmark will be equal to:
- angle in thousandths, measured by a ruler located at a distance of 50 cm from the eye, (1 mm is 0-02) between two telegraph poles 0-32 (telegraph poles are 50 m apart). Therefore, the distance to the landmark will be equal to:
- tree height in thousandths, measured with a ruler 0-21 (true tree height 6 m). Therefore, the distance to the landmark will be equal to:
Determination of distance on the ground
To learn how to calculate distances, you first need to find out the length of your step, your height and the thickness of the finger you are sighting. In addition, it is necessary to get an idea of how far the horizon line lies from the observer. In other words, you need to know at what distance a hunter can survey the surrounding terrain. For this purpose, you should use the formula: Horizon distance = 113 √ h km , where h is the observer height in km.
Standing on a plain, a person with a height of 1.6 m sees the surrounding area by 131 √ 0.0016 = 4.52 km. Sitting in a boat and towering above the water only for 1 m, a person can observe the surrounding area only for 113 √ 0.001 = 3.58 km. Of course, in reality, the horizon distance increases, since the earth's atmosphere, bending the path of light rays (refraction), as if moves the horizon by about 6% compared with the figures obtained from the formula. Because of this, a person 1.6 m tall sees the surrounding area at 4.8 km. The horizon visibility range also increases when atmospheric pressure rises, in cold weather, as well as in the morning and evening.
But from what height and at what distance the horizon is seen:
For eye estimation of distance, you can use the following table:
Features vision on the route of various items. Depend on many factors, and primarily on the distance to objects.
The farther the object is located, the lower it looks and narrower than in reality.
Therefore, large objects seem closer than small ones. Lying objects (for example, a fallen tree) appear longer than those of the same size:
When orienting and estimating the distance along the route, one should remember that the steepness of the bare slopes usually seems to be greater than forested; the distance to the far forest, river, mountain is shorter than the real one; flat road - less long than the same road on the road.
Especially “extended” kilometers, traveled under a heavy backpack, in bad weather or in conditions of poor visibility:
The distance on the water, in the gorge, in the snow seems shorter than the actual. The width of the river from a sloping bank appears to be larger than when observed from a steep bank.
When viewed from the top up, from the foot of the mountain to its top, the slope seems less steep, and the objects on the mountain are closer than when viewed from the top down, from the mountain. At night, all sources of light and brightly lit objects appear much closer to their actual position.
During the daytime, light or brightly colored objects appear closer than dark or little contrast objects to the natural background:
Table of the distance of the beginning of the visibility of objects:
Determination of distance using the AK-47/74 front sight:
Naturally, these data are rounded, but it is an order of magnitude more accurate than determining the distance to the eye: Average height - 1.75 m., Running -1.5 m., Shoulders -0.5m, in winter clothes shoulders -0.6 m.
Items and distance to them
- Locations 10-12 km
- Large buildings 8 km
- Separate small houses 5 km
- Windows in houses (without binding) 4 km
- Roof pipes 3 km
- Individual trees 2 km
- People (in the form of points) 1.5-2 km
- Human leg and arm movements 700 m
- Covers window frames 500 m
- Human head 400 m
- Color and parts of clothing 250-300 m
- Leaves on trees 200 m
- Facial features, hands 100 m
- Eyes (as dots) 60-70 m
- Bell towers and large towers 15000—20000 m
- Windmills 10,000m
- Villages and big houses 8000 m
- House windows 4000 m
- Roof pipes 3000 m
- Individual trees 2000 m
- People like point 2000 m
- Distinguish a rider from a pedestrian 1000 m
- Trunks of trees 900 m
- Distinguish foot from equestrian 700 m
- Horse leg movement 600 m
- Binding on the windows 500 m
- Hand movement 400 m
- Colors and pieces of clothing 250 m
- Human face 200 m
- Tiles and boards on the roof 200 m
- Buttons and metal jewelry clothing 150 m
- Facial expression 100 m
- Eyes (seem like separate points) 70 m
- Eyes and mouth (clearly distinguished) 35 m
- Eye protein 20 m
- Burning fire 6-8 km
- Light flashlight 1.5-2 km
- Burning match 1-1,5 km
- Fire cigarettes 400-500 m
Of course, when eyeing distances, it is necessary to take into account the fact that people's vision is different. Therefore, when using the table, it is necessary to check the given data in practice and make the necessary correction for yourself.
In addition, you should always remember:
- Brightly lit objects appear closer. For example, a bonfire or fire always seems closer than the true distance.
- Objects painted in bright colors — white, yellow, and red — seem closer.
- In the mist, the distances seem larger, and after rain, when there is no dust, closer. At twilight, all objects appear farther.
- When the sun is ahead of the observer, the estimated distances are shorter, and when the sun behind is more true.
- Large objects seem closer than small ones.
- Objects located on level ground seem closer than the same objects located on hilly terrain or behind any barriers. That is why the opposite bank of a river or lake always seems closer than it actually is.
- When viewed from the bottom up, objects appear closer than when viewed from top to bottom. For this reason, the person who is at the foot of the mountain, the mountain always seems steeper.
- The darker the background on which the subject is located, the further it seems. Because of this, a house against the sky always seems closer than the same house against a dark background of forest or mountain.
The accuracy of eye-determining distance depends on the skill, as well as the size of the measured distances. In determining the distance over 1 km error can reach 50%. At small distances for experienced observers, the error does not exceed 10%.
Determining distance by measuring angles
This method requires more training. The starting position for measuring distances in this way is the following rule: each object, seen at an angle of 1 °, is removed by a distance of 57 times its diameter. The object, visible at an angle of 2 °, is removed by 28 diameters; at an angle of 5 ° - 11 widths; at an angle of 7 ° - 8 diameters, t, d. If you know the angle at which the object is visible, you can approximately determine the distance to it. The easiest way to measure is with the index finger. You need to stretch your hand and raise your index finger (the distance from your finger to the eyes is taken 60 cm). An object that is covered with the nail of the index finger (the nail is 1 cm wide) is usually visible at an angle of 1 ° and is 57 times longer than its diameter. If the nail covers only half of the object, then its angular value is 2 °, and the distance to it is equal to 28 of its width. For measurements, you can use the nail joint of the thumb. Its length is usually 3.5 cm. An object that is covered by this joint with an outstretched arm is visible at approximately 3 ° angle and removed at a distance 18 times longer than its diameter.
Determining the height of objects
There are several simple ways to determine the height of objects. Hunters should be familiar with some of them.
By the shadows. On a sunny day, it is not difficult to measure the height of an object, suppose a tree, by its shadow. It is only necessary to be guided by the following rule: the height of the tree being measured is so many times greater than the height of the object you know (for example, a stick or a gun), how many times the shadow of a tree is greater than the shadow of a stick. If, in our measurement, the shadow of a gun or stick is twice the length of a gun or stick, then the height of the tree will be half the length of its shadow. In the same case, when the shadow of a gun or stick will be equal to their length, the height of the tree is also equal to its shadow.
By the pole This method can be used when there is no sun and no shadow from objects is visible. To measure you need to take a pole equal in length to your height. This pole must be installed at such a distance from the tree so that when lying down one can see the top of the tree in one straight line with the top point of the pole. Then the height of the tree will be equal to the line drawn from your head to the base of the tree.
Over a puddle. This method can be successfully applied after rain, when there are many puddles on the ground. The measurement is carried out in such a way: a puddle is found not far from the object being measured and become near it so that it is placed between you and the object. After this, a point is found from which the object's tip reflected in the water is visible. The measured object, for example a tree, will be so many times taller than you, how much is the distance from it to the puddle more than the distance from the puddle to you. Instead of a puddle, you can use a horizontal mirror.
Determination of the width of water bodies
The first way. It is necessary to approach as close as possible to the water and notice on the opposite shore two any objects located at the very edge of the water. Then you need to take a blade of grass (wand, string) and, holding it horizontally by the ends with both arms extended, close one eye. Looking over the blade of grass, it is necessary to close the gap between the observed landmarks. After that, note the point where you are, fold the blade of grass in half and move away from the reservoir at a right angle to another point, from which the distance between the landmarks will be closed with a shortened blade of grass. The distance from this point to the river, where you measured for the first time, will be equal to the width of the reservoir.
The second way. You need to go to the water, detect any clearly visible object A, located at the very edge of the water, and mark the point of your standing with a stone or a peg B. Then you need to walk along the coast along a line perpendicular to the direction between A and B, exactly 30 steps, stick stick B, count 30 more steps and make a new note G. After that, turning your back to the bank, you need to go from note D to point D until the stick is in line with the object behind river A. Distance DG and will be equal to the width of the reservoir
The third way. It is necessary to push a cap or cap over the head, go up to the shore and look at it so that the visor covers the shore. After that, without changing the inclination of the head, it is necessary to turn around and see a place on the shore, which is covered with a visor. The number of steps to this point on your shore will indicate the width of the reservoir. ”
The table shows the range of onset of hearing of sounds in open areas in quiet conditions and with normal humidity.
At night and in the fog, when observation is limited or impossible at all (and on very rough terrain and in the forest, both at night and during the day), hearing comes to the aid of the sight.
We must learn to determine the nature of sounds (that is, what they mean), the distance to the sources of sounds and the direction from which they originate.
If different sounds are heard, the person must be able to distinguish them from one another. The development of this ability is achieved by a long workout (in the same way, a professional musician distinguishes the voices of the instruments in the orchestra).
Almost all sounds that mean danger are made by man.
Therefore, if a person hears even the faintest suspicious noise, he should stand still and listen.
It is possible that the enemy is not far from him.
If the enemy begins to move first, thereby giving out his location, he will be the first to die.
In the same way, an inexperienced or impatient hunter betrays his presence to the beast that he hunts.
A skilled hunter, by his own perseverance, surpasses animals.
On a quiet summer night, even an ordinary human voice can be heard in the open, far away, sometimes for half a kilometer.
In a frosty autumn or winter night, all kinds of sounds and noises are heard very far.
This applies to speech, and footsteps, and the clinking of dishes or weapons.
In foggy weather, sounds are also heard far away, but their direction is difficult to determine.
On the surface of calm water and in the forest, when there is no wind, the sounds are carried over a very long distance.
But the rain is very deafening sounds.
The wind blowing towards the person brings the sounds closer, and o removes them from it.
He also puts the sound aside, creating a distorted view of the location of its source.
Mountains, forests, buildings, ravines, ravines and deep ravines change the direction of the sound, creating an echo.
Echoes and water spaces are generated, contributing to its spread over long distances.
The sound changes when its source moves along soft, wet or hard soil, down the street, along a country or field road, along pavement or leaf-covered soil.
It must be borne in mind that dry earth conveys sounds better than air.
Therefore, listen, putting his ear to the ground or to the trunks of trees.
At night, sounds are well transmitted through the earth.
There are certain ways to help listen at night, namely:
- lying: put ear to the ground;
- standing: one end of the stick to lean against the ear, the other end to rest against the ground;
- leaning over: standing, slightly leaning forward, shifting the center of gravity of the body to one leg, with the mouth half-open, the teeth are a conductor of sound.
When creeping, a trained person, if only life is dear to him, lies on his stomach and listens while lying, trying to determine the direction of the sounds.
It is easier to do this by turning one ear in the direction from which a suspicious noise is coming.
In order to improve hearing, it is recommended to attach bent palms, a kettle, a pipe section to the auricle.
In order to better listen to the sounds, a person can put his ear to a dry board on the ground, which acts as a sound collector, or to a dry log dug into the ground.
If necessary, you can make a homemade water stethoscope.
To do this, use a glass bottle (or a metal flask), filled with water to the neck, which is buried in the ground to the level of water in it. In a cork tightly insert the tube (plastic), which put a rubber tube. The other end of the rubber tube, provided with a tip, is inserted into the ear.
To check the sensitivity of the device, hit the ground at a distance of 4 m from it (the sound from the impact is clearly audible through the rubber tube).
Sources of sound (Medium range of onset of hearing):
- The noise of a walking train 5-10 km
- Shooting with a hunting rifle 2–4 km
- Harsh noise of the tractor engine, tractor, hoots of a car 2–3 km
- Dog bark, horse neighing 1-2 km
- The movement of cars on the highway 1 - 2 km
- Loud cry (unintelligible) 1–1.5 km
- The movement of cars on a dirt road 0.5-1 km
- Fall, crackling of felled wood 800 m
- Ax knocking, saw screeching, kettle tinkling 300–500 m
- Talking people (unintelligible) 200 m
- Quiet speech, cough 50-100 m