Orientation in the area In order not to get lost or go astray, a fighter must always know where he is. To do this, he must be able to navigate the terrain, i.e. find directions to the cardinal directions (north, south, east and west) and determine his

Movement in mountainous areas The actions of landing groups in the mountains differ significantly from actions on flat terrain. When moving in the mountains, on the path of the paratroopers there will be stormy rivers, rocks, impassable gorges, ridges, mountain passes, ice and snow

Studying the area using a map A topographic map is one of the main sources of obtaining information about the area. Using the map, you can relatively quickly study and evaluate the nature, tactical and protective properties of the terrain in the area of ​​upcoming actions, regardless of

4.3. Measuring angles and distances on the ground The concept of thousandths When measuring angles, determining distances and target designation, military reconnaissance officers usually use the reference system adopted in artillery. Its essence lies in the fact that when dividing a circle by 6000

Determining distances on the ground Very often, a scout needs to determine the distances to various objects on the ground, as well as estimate their sizes. Distances are determined most accurately and quickly using special devices (rangefinders) and

Determining distances on the ground Very often, a scout needs to determine the distances to various objects on the ground, as well as estimate their sizes. Distances are determined most accurately and quickly using special devices (rangefinders) and

Orientation on the terrain In order not to get lost or go astray, a fighter must always know where he is, for this he must be able to navigate the terrain, i.e. find directions to the cardinal directions (north, south, east and west) and determine your

Moving over rough terrain Dislocations, sprains. A tight bandage is applied and the joint is immobilized.

British patriotism without distance Just shortly before our business trip, Argentine Foreign Minister Guido Di Tella addressed all residents of this archipelago. He urged them to stop recognizing British rule and return to the fold

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Introduction 2

1. The concept of a thousandth and how to measure it 3

2. Eye method 5

3. Method of measuring by angular dimensions 7

4. Linear measurement method 10

5.Measuring method in steps 11

6. Method of measuring time and speed 12

7. Method of measurement based on the ratio of the speed of light and sound 13

8. Method of measuring by ear 13

Conclusion 18

Bibliography 19

Application 20

Introduction

The organization and conduct of combat operations are inextricably linked with terrain orientation. It is necessary when assigning combat missions to units and firepower, maintaining the direction of action, target designation, plotting the results of enemy and terrain reconnaissance on a working map, and controlling units during the battle. Loss of orientation in combat can lead to failure to complete the combat mission and unjustified losses of personnel and equipment. Therefore, the ability to quickly and accurately navigate the terrain in any conditions is one of the most important elements of field training for officers.

The use of modern fire weapons in combat requires precise measurements and calculations to link firing and launch positions, and determine distances to targets. For this purpose, the troops use various types of measurements using different instruments. Topographic maps are widely used for field measurements.

However, in modern combat, when success depends on quick decision-making, when it takes a short time to make a decision, it is necessary that every soldier, and even more so an officer, must be able to quickly and with high accuracy make measurements and calculations on the ground, especially in determining distances to goals.

This is especially important for commanders of motorized rifle units. During combat, commanders of motorized rifle units are required to control units and fire on the ground; determining distances and angles during reconnaissance of targets plays a very important role in quickly destroying the enemy.

Determining distances on the ground is necessary for the commander to control the unit in battle. Determining distances has a particularly large impact on firing from various types of weapons.

1. The concept of a thousandth and how to measure it

Thousandth is a unit of measurement of angles adopted in artillery and equal to one six-thousandth of a revolution. The name comes from the approximate equality of such a unit of measurement of angles to the milliradian, that is, a thousandth of a radian (component 1/(1000 × 2 π) ≈ 1/6283 of a revolution). A synonym for this unit of angle measurement is the minor division of the protractor.

The concept of a thousandth is accepted in all countries of the world, and is used to introduce horizontal corrections for the firing of small arms and artillery systems, as well as to determine distances and distances. Thousands are written and read as follows:

thousandth 0-01, read as zero, zero one

thousandths 0-05, read as zero, zero five

thousandths 0-10, read as zero, ten

thousandths 1-50, read as one, fifty

thousandths 15-00, read as fifteen, zero zero

When using optical instruments with divisions in thousandths, you need to take into account that there is a Russian thousandth, which divides the circle into 6000 parts, and there is a German thousandth, which divides the circle into 6400 parts.

Based on the equality of 1 revolution to 2π radians or 360 degrees, there are the following relationships between all these units of measurement:

· 1 thousandth ≈ 0.00016(6) revolution

· 1 thousandth ≈ 0.001047 radian

· 1 thousandth = 0.06 degrees = 3.6 arc minutes = 3 arc minutes. minutes 36 arc. seconds

· 1 thousandth = 0.06(6) degrees

· 1 revolution = 6000 thousandths

· 1 radian ≈ 954.92 thousandths

· 1 arcsecond = 0.004629(629) thousandths

1 arc minute = 0.277(7) thousandths

· 1 degree = 16.66(6) thousandths

· 1 degree = 15 thousandths

The great convenience of such a non-standard unit of measuring angles is its good adaptability to calculating the linear and angular dimensions of objects on the ground without any means of mechanized calculation. Let the object be of length W observed from a distance L at a small angle α (that is, the condition is satisfied L >> W, very common in artillery practice). Then, when expressing the angle α in radian measure, the following holds:

and, replacing the radian measure with thousandths, we end up with:

For most practical calculations, an approximate version is used, but in some cases the resulting error of 4.5% is unacceptable and then the coefficient of 0.955 is not discarded. The simplified equation is called the thousandths formula. From this formula follows a rule for better remembering the ratio: “a pole 1 meter high, 1 kilometer away from the observer, is visible at an angle of 1 thousandth.”

The thousandths formula is applicable for angles that are not too large, when the sine of the angle is approximately equal to the angle itself in radian measure. The conditional limit of applicability is an angle of 300 thousandths (18 degrees).

2. Eye method

The eye method is the main method and the simplest for determining distances, available to every commander. The essence of the method is to compare the determined distance with a known one or imprinted in memory.

This method does not provide high accuracy in determining distances, but with some training you can achieve an accuracy of up to 10 m. To develop your eye, you need to constantly practice determining distances on the ground.

The distance is determined by eye by comparison with a segment known on the ground. The accuracy of visual distance determination is influenced by illumination, the size of the object, its contrast with the surrounding background, the transparency of the atmosphere and other factors. Distances appear smaller than in reality when observing through bodies of water, ravines and valleys, and when observing large and isolated objects.

Conversely, distances appear greater than in reality when observed at dusk, against the light, in fog, in cloudy and rainy weather. All these features should be taken into account when determining distances by eye.

The accuracy of visual determination of distances also depends on the training of the observer. An experienced observer can determine distances up to 1000 m by eye with an error of 10-15%. When determining a distance of more than 1000 m, errors can reach 30%, and if the observer is insufficiently experienced, 50%.

One of the ways to measure distances on the ground is to use distances on the ground known by their length (power lines - the distance between supports, the distance between communication lines, etc.).

To roughly estimate distances on the ground, you can use the following data (Table 1):

Table 1

Distances of visibility (discernibility) of some objects with the naked eye

For each person, this table can be clarified by himself. To develop your eye, you need to practice determining distances by eye as often as possible, with the obligatory check of them in steps, on a map or in another way.

Training should begin with short distances (10, 50, 100 m). Having mastered these distances well, you can move on to larger distances (200, 400, 800, 1000 m). Then you can easily determine distances and large ones.

larger objects always seem closer than small ones located at the same distance;

the fewer intermediate objects there are between the eye and the observed object, the closer this object seems;

when observed from bottom to top, from the base of the mountain to the top, objects appear closer, and when observed from top to bottom, objects appear further away.

Eye estimation of distances can be controlled when several people measure the same distance independently of each other. Taking the average of all these determinations gives the most accurate measurement.

. Method of measuring by angular dimensions

To apply this method, you need to know the linear size of the observed object (its height, length or width) and the angle (in thousandths) at which this object is visible. The angular dimensions of objects are measured using binoculars, observation and aiming devices, and improvised means. The distance to objects in meters is determined by the formula:

where B is the height (width) of the object in meters, Y is the angular value of the object in thousandths.

For example, the height of a railway booth is 4 meters, a soldier sees it at an angle of 25 thousandths (the thickness of a little finger). Then the distance to the booth will be:

Or a serviceman sees a Leopard-2 tank at a right angle from the side. The length of this tank is 7 meters 66 centimeters. Let's assume that the viewing angle is 40 thousandths (the thickness of the thumb). Therefore, the distance to the tank is 191.5 meters.

To determine the angular value using available means, you need to know that a segment of 1 mm, distant from the eye by 50 cm, 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 accuracy of determining distances by angular values ​​is 5-10% of the length of the measured distance.

To determine the angular value, you need to know that a segment of 1 mm, distant from the eye by 50 cm, corresponds to an angle of two thousandths (written: 0-02). From here it is easy to determine the angular value for any segments (Fig. 1).

Fig.1. Determining 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 is to memorize the standard values ​​of thousandths:

table 2

Angular values ​​(in thousandths of distance)

4. Linear measurement method

Determining distances based on the linear dimensions of objects is as follows. Using a ruler located at a distance of 50 cm from the eye, measure the height (width) of the observed object in millimeters. Then the actual height (width) of the object in centimeters is divided by that measured by a ruler in millimeters, the result is multiplied by a constant number 5 and the desired height of the object in meters is obtained.

For example, a telegraph pole 6 m high (see figure) covers a 10 mm segment on the ruler.

Fig.2. Determining distances based on the linear dimensions of an object

Therefore, the distance to it is:

The accuracy of determining distances using linear values ​​is 5-10% of the length of the measured distance.

To determine distances based on the angular and linear dimensions of objects, it is recommended to remember the values ​​(width, height, length) of some of them, or to have this data at hand (on a tablet, in a notebook). The dimensions of the most frequently encountered objects are given in the Appendix.

5.Measuring method in steps

measurement distance visibility size

This method of determining distances in a combat situation has limited use

This method is usually used when moving in azimuth, drawing up terrain diagrams, drawing individual objects and landmarks on a map (scheme), and in other cases. Steps are usually counted in pairs. When measuring a long distance, it is more convenient to count steps in threes, alternately under the left and right foot. After every hundred pairs or triplets of steps, a mark is made in some way and the countdown begins again. When converting the measured distance in steps into meters, the number of pairs or triplets of steps is multiplied by the length of one pair or triple of steps. For example, there are 254 pairs of steps taken between turning points on the route. The length of one pair of steps is 1.6 m.

Then D = 254X1.6 = 406.4 m.

Typically, the step of a person of average height is 0.7-0.8 m. The length of your step can be determined quite accurately using the formula

D=(P/4)+0.37,

where D is the length of one step in meters

P is a person’s height in meters.

For example, if a person is 1.72 m tall, then his step length is

D=(1.72/4)+0.37=0.8 m.

More precisely, the step length is determined by measuring some flat linear section of terrain, for example a road, with a length of 200-300 m, which is measured in advance with a measuring tape (tape measure, range finder, etc.). When measuring distances approximately, the length of a pair of steps is taken to be 1.5 m.

The average error in measuring distances in steps, depending on driving conditions, is about 2-5% of the distance traveled.

Steps can be counted using a pedometer (Fig. 3).

It has the appearance and dimensions of a pocket watch. A heavy hammer is placed inside the device, which lowers when shaken and returns to its original position under the influence of a spring. In this case, the spring jumps over the teeth of the wheel, the rotation of which is transmitted to the arrows. On the large scale of the dial, the hand shows the number of units and tens steps, on the right - small hundreds, and on the left - small thousands. The pedometer is hung vertically from clothing. When walking, due to vibration, its mechanism comes into action and counts each step.

Fig.3 Pedometer

6. Method of measuring time and speed

This method is used to approximate the distance traveled, for which the average speed is multiplied by the time of movement. The average walking speed is about 5, and when skiing 8-10 km/h. For example, if a reconnaissance patrol skied for 3 hours, then it covered about 30 km.

7. Method of measurement based on the ratio of the speed of light and sound

This method allows you to quickly determine the distance to firing guns, mortars, tanks and other fire weapons.

Sound travels in the air at a speed of 330 m/s, i.e. approximately 1 km per 3 s, and light travels almost instantly (300,000 km/h). Thus, the distance in kilometers to the location of the flash of a shot (explosion) is equal to the number of seconds that passed from the moment of the flash to the moment when the sound of the shot (explosion) was heard, divided by 3. For example, the observer heard the sound of an explosion 11 s after the flash. Distance to the flash point D = 11/3 = 3.7 km.

8. Method of measuring by ear

At night and in fog, when observation is limited or impossible at all (and in very rough terrain and in the forest, both at night and during the day), hearing comes to the aid of vision.

Almost all sounds that indicate danger are made by humans. Therefore, if a soldier hears even the faintest suspicious noise, he should freeze in place and listen. It is possible that an enemy is hiding not far from him. If the enemy starts moving first, thereby giving away his location, then he will be the first to die. If a scout does this, the same fate will befall him.

On a quiet summer night, even an ordinary human voice in an open space can be heard far away, sometimes half a kilometer. On a frosty autumn or winter night, all kinds of sounds and noises can be heard very far away. This applies to speech, steps, and the clinking of dishes or weapons. In foggy weather, sounds can also be 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, sounds travel a very long distance. But the rain greatly muffles the sounds. The wind blowing towards the soldier brings sounds closer and away from him. It also carries sound away, creating a distorted picture of the location of its source. Mountains, forests, buildings, ravines, gorges and deep hollows change the direction of sound, creating an echo. They also generate echoes and water spaces, facilitating its spread over long distances.

The sound changes when its source moves on soft, wet or hard soil, along the street, along a country or field road, on pavement or soil covered with leaves. It must be taken into account that dry soil transmits sounds better than air. At night, sounds are transmitted especially well through the ground. That’s why they often listen by putting their ears to the ground or tree trunks.

A trained ear is a good helper in determining distances at night. The successful use of this method largely depends on the choice of listening location. It is chosen in such a way that the wind does not get directly into the ears. Around a radius of several meters, the causes of noise are eliminated, for example, dry grass, bush branches, etc. On a windless night with normal hearing, various sources of noise can be heard at the ranges indicated in the table. 3.

Table 3

Average range of audibility of various sounds during the day on flat terrain, km (summer)

There are certain ways to help you listen at night, namely:

· lying down: put your ear to the ground;

· standing: lean one end of the stick against your ear, rest the other end on the ground;

· stand slightly leaning forward, shifting the center of gravity of the body to one leg, with a half-open mouth - the teeth are a conductor of sound.

A trained soldier, when sneaking up, if only his life is dear to him, lies on his stomach and listens while lying down, trying to determine the direction of the sounds. This is easier to do by turning one ear in the direction from which the suspicious noise is coming. To improve audibility, it is recommended to apply bent palms, a bowler hat, or a piece of pipe to the auricle.

To better listen to sounds, a soldier can put his ear to a dry board placed 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 metal flask), filled with water up to the neck, which is buried in the ground until the water level in it. A tube (plastic) is tightly inserted into the cork, onto which a rubber tube is placed. The other end of the rubber tube, equipped with a tip, is inserted into the ear. To check the sensitivity of the device, hit the ground with your finger at a distance of 4 m from it (the sound of the impact is clearly audible through the rubber tube).

When learning to recognize sounds, it is necessary to reproduce the following for educational purposes:

· Extraction of trenches.

· Dropping sandbags.

· Walking on the boardwalk.

· Hammering the metal pin.

· Sound when operating the shutter of a machine gun (when opening and closing it).

· Putting a sentry on duty.

· The sentry lights a match and lights a cigarette.

· Normal conversation and whispering.

· Blowing nose and coughing.

· The sound of breaking branches and bushes.

· Friction of a weapon barrel against a steel helmet.

· Walking on a metal surface.

· Cutting barbed wire.

· Concrete mixing.

· Shooting from a pistol, machine gun, machine gun with single shots and bursts.

· Engine noise of a tank, infantry fighting vehicle, armored personnel carrier, vehicle on the spot.

· Noise when driving on dirt roads and highways.

· Dogs barking and yelping.

· The noise of a helicopter flying at different altitudes.

Conclusion

Commanders of motorized rifle units must be able to determine distances in various ways: by eye, using the rangefinder scale of sights and observation devices and by the measured angular magnitude of objects on the ground, by the speedometer of the car, by measuring in steps, by the average speed of movement.

The basis of any method of determining distances is the ability to select landmarks on the ground and use them as markers indicating the desired directions, points and boundaries.

The selection and determination of landmarks is an important event in the work of a commander when working on the ground.

Bibliography

1. Baranov A.R., Maslak Yu.G., Yagodintsev V.I. Military topography in the service and combat activities of operational units - M.: Academic Project, 2005.

2. Military topography. // Under general ed. V. N. Filatova: textbook for higher military educational institutions. - Military Publishing House, 2008.

Military topography.// Edited by A. V. Markelenko. - M.: Phoenix Publishing House, 2008.

Measuring and orienting on terrain without a map. Movement along azimuths. Lecture. Ural State University named after. A. M. GORKY. - Ekaterinburg, 2003.

Presnyakov P.R., Andriyasov A.T. Military topography. - M.: Phoenix Publishing House, 2008.

Application

Linear dimensions of some objects

Moving along the route, tourists take the necessary measurements on the ground. For example, they measure the distance traveled between the reference points of the day's crossing, the length of natural obstacles (the width of the river at the crossing point, the length of the slope), etc. Below we present information about common methods of measuring these parameters in tourism.

How can you determine the required distances on the ground? In tourist practice, the simplest methods of determining distances on the ground are used: by eye, by measuring in steps, by linear values ​​of observed objects, by time and speed of movement. Eye assessment is the fastest way to determine distances, often used in hiking conditions, but requiring a lot of preliminary training. To develop your eye, you need to practice estimating distances by eye as often as possible in different terrain conditions at different times of the year and day, with the obligatory check of them in steps or on a map. First of all, you need to learn to mentally imagine and confidently distinguish several distances that are most convenient as standards on any terrain. You need to start with distances of 10, 50, 100m and, only having firmly mastered them, move on to segments from 200 to 1000m. Having fixed certain reference segments in visual memory, you can then mentally compare distances of interest with them (Aleshin, Serebryannikov, 1985). When training your eye, you should keep in mind that the assessment of distances is influenced by a number of factors, such as illumination, the nature of the terrain, the contrast of the objects in question with the surrounding background and their sizes. For example, objects appear closer than they actually are if they are brightly lit against a dark background or, conversely, if dark objects are observed against a light background. Larger objects also seem closer compared to small objects located at the same distance, as well as any objects when observed from bottom to top, for example, from the foot of a mountain to the top. And vice versa, objects “move away” from the observer: at dusk, when observed against the light and at sunset; in fog, cloudy and rainy weather; when observing from top to bottom, from top to bottom, and in a number of other cases. The accuracy of eye measurements depends on the training of tourists, the distance, and observation conditions. Typically, an experienced observer for distances of 1-1.5 km does not make errors of more than 10-15%. When estimating large distances, the error increases to 30% and even 50%. Some idea of ​​the visual assessment of distances is given by Table 1, which shows the maximum visibility distances of objects in the daytime for a person with normal vision (Aleshin, Serebryannikov, 1985).

Table 1.

Limit distances for the visibility of certain objects for a person with normal vision.

Measuring distances in steps is a simple and fairly accurate way to determine distances. It is used when measuring relatively short sections of a path: moving from one landmark to another, count the number of paired steps. The length of a double step can be determined by the empirical formula: L=2(H/4+37) where L is the length of a double step, H is a person’s height (cm), and 4 and 37 are constant numbers. But the measurement will be more accurate if you know the number of your paired steps corresponding to 100m on the ground. Determining your number of pairs of steps in 100m is not difficult. It is known that a person of average height takes 62-66 paired steps when moving 100m along a path. It should be noted, however, that step length changes when moving in different conditions (on the road, grass, moss, thickets, up or down a slope). Therefore, it is necessary to make adjustments to the given specific conditions in the known value of pairs of steps in 100m of an ordinary road. The accuracy of step measurements depends on the training of the tourist and the nature of the terrain. When mastering certain skills on flat terrain, measurement errors do not exceed 2-4% of the distance traveled (Aleshin, Serebryannikov, 1985).

Determining distances by time and speed of movement is used on a hike as an auxiliary method for general orientation on the ground. This method is convenient when measuring long sections of a path (for example, the length of individual transitions along linear landmarks of the area). The time of movement can be determined quite accurately using a wristwatch. The situation is more complicated with determining the average speed of a group in traveling conditions. Moreover, difficulties arise both with determining the absolute value of the speed and with maintaining its constancy. On a flat road, the average speed of a person (at a fast pace) is 5-6 km per hour. Of course, the speed of the group, taking into account the load being carried, is lower on foot. At the end of the “working” day, as fatigue accumulates, the speed of movement also drops. In each specific case, it is necessary to try to determine the speed of movement of the group along known sections of the path. Speed ​​measurements are carried out several times in the first days of the hike and then you can use the resulting average speed value, adjusted for the physical condition of the group, the nature of a specific section of the route, etc.

The method of determining distances from the known linear dimensions of an observed object is used if direct measurement of the distance to a given object in steps is impossible for some reason. The essence of this method is presented in Fig. 3. The observer holds a ruler (for example, the ruler of the backing of a sports compass) in front of him perpendicular to the line of sight at a distance of 50 cm from the eyes and determines from it the value of the segment (in this case it is 2 cm) covering the observed object (a tree of height 20m). From the rule of similarity of triangles it follows that the required distance to the tree is 2000cm x 50cm / 2cm = 50000cm (500m).

Fig.3

The width of a river (or other obstacle) on the ground can be measured by the so-called. geometrically (steps followed by converting the resulting value into meters (Fedotov, Vostokov, 2003)). To do this (Fig. 4), first select a noticeable landmark on the edge of the opposite bank of the river. Then they stand opposite the selected landmark and at right angles to the direction of the landmark, counting a certain number of steps along the shore, for example 50. They place a pole at this place and continue to walk in the same direction, counting the same number of steps. Next, they change the direction of movement and walk at right angles from the shore until they find themselves on the same straight line with the pole and the selected landmark (on target). The number of steps from the shore to our stop at the target is the desired width of the river in steps. Converting it into meters is not difficult, knowing the number of your pairs of steps in 100m. The average step length is 0.7-0.8m.

In what ways can you determine the directions of movement on the ground (cardinal directions)? Obviously, the most common way to determine the required direction of movement of tourists on a hike is to use a special tool - a compass. The compass indicates directions to all cardinal directions; Using a compass you can measure the required directions of movement. The procedure for measuring azimuths on the map was presented above. In this section, we outline the procedure for determining the azimuth to a selected landmark (this technique is called “sighting” or “determining bearing”). The sighting technique is used, in particular, when determining the standing point using the resection method.

Rice. 4 Scheme for measuring the width of a river using a geometric method. The distance “VG” is equal to the width of the river (the distance from point A on one bank to a selected, observed landmark on the other bank) (according to Vyatkin L.A. et al., 2001).

To measure the required azimuth, the long edge of the compass base (the direction indicator on the base) is directed to the target terrain landmark. At the same time, hold the compass horizontally at eye level and look at the landmark along the edge of the substrate. Next, by rotating the scale of the compass bulb, make sure that the red compass needle points to the value of “zero degrees” of the azimuth scale, corresponding to the direction to the north (in this case, the arrow is located inside the special marks of the north indicator marked on the bottom of the bulb). Finally, read off the value of the desired azimuth on the scale opposite the azimuth line.

If a tourist does not have a compass at his disposal, then the cardinal directions can be determined, for example, by the celestial bodies (see also the lecture “Fundamentals of terrain orientation techniques”). On a sunny day

The cardinal directions can be approximately determined by the shadow of an object. A stick is stuck on a flat surface of the ground (Fig. 5) so that it casts a distinct shadow. The tip of the shadow is marked on the ground (for example, with a stone). Next, wait at least 15 minutes for the shadow to move a few centimeters away from its original position and place a second mark on the tip of the displaced shadow. Attention! The longer the waiting time, the more accurate the final measurement result. A line drawn through two marks indicates the east-west direction, with the first mark always being west.

The cardinal directions can also be determined by the Sun and mechanical watches. By placing the clock horizontally and pointing the hour hand to the Sun, we obtain the direction of the north-south line as a bisector between the hour hand and the direction to the number 12 (Fig. 6). Naturally, before noon it is necessary to divide in half the arc that the clock hand has until 12 o’clock to go through, and after noon - the arc that the hand has already passed after 12 o’clock (Aleshin, Serebryannikov, 1985). This determination method is again indicated for local (solar) time and it will “work” if any clocks in the group are set to this time. In the usual case, an adjustment should be made for maternity and summer time. When determining directions using a watch, the higher the Sun, the greater the measurement error.

You can reliably determine the cardinal directions without a compass in the forest using clearings and quarter posts. Clearings usually divide the forest into squares with a side of 2 km (quarters). Quarters are numbered in a given forestry in the direction from west to east (increasing numbers from left to right), reach the border of the neighboring forestry and continue numbering in accordance with the transfer rules.

Rice. 6

Thus, the block numbers indicated on the quarter post standing at the intersection of the clearings change by one unit from west to east, and a sharp jump in numbering by more than two units indicates a more southern quarter (Fig. 7).

What technique do tourists use to navigate accurately in a given direction using a compass? Exact movement in azimuth is carried out as follows (Fig. 8).

· Set the desired azimuth reading on the compass scale, taking into account the magnetic declination of the area (you are already familiar with these operations).

· Then, holding the compass in front of you, turn your whole body, right or left, so that the red compass needle is positioned between the marks of the north indicator drawn on the bottom of the flask (then the scale value 0?, corresponding to North, will coincide with the direction to the North of the area).

· As a result, the long edge of the backing (the direction indicator on the backing) of the sports compass will show the desired direction of movement.

Rice. 8.

The tourist marks out some object (tree, bush, etc.) strictly in the direction indicated by the compass. This object will be the first intermediate landmark. It is only necessary that the landmark be sufficiently noticeable and not lost from sight when approaching it. Having reached the first intermediate landmark, in the same order, use the compass to determine the second intermediate landmark and move until they reach it. Having reached the second intermediate landmark, they find a third landmark, etc. In the absence of visible landmarks in the direction of movement (during prolonged movement in conditions of limited visibility), tourists simply move in the direction indicated by the side edge of the compass base, holding the red arrow between the marks of the North indicator at the bottom of the compass bulb.

Very often, a scout needs to determine the distances to various objects on the ground, as well as estimate their sizes. Distances are most accurately and quickly determined using special instruments (rangefinders) and rangefinder scales of binoculars, stereo scopes, and sights. But due to the lack of instruments, distances are often determined using improvised means and by eye.

Among the simplest ways to determine the range (distances) to

objects on the ground include the following:

Eye-catching;

By linear dimensions of objects;

By visibility (discernibility) of objects;

By the angular size of known objects;

By sound.

By eye - this is the easiest and fastest way. The main thing in it is the training of visual memory and the ability to mentally lay down a well-imagined constant measure on the ground (50, 100, 200, 500 meters). Having fixed these standards in memory, it is easy to compare with them and

estimate distances on the ground.

When measuring a distance by successively mentally putting aside a well-studied constant measure, one must remember that the terrain and local objects seem reduced in accordance with their distance, that is, when removed twice, the object will seem smaller.

two times less. Therefore, when measuring distances, the mentally plotted segments (measures of terrain) will decrease according to the distance.

The following must be taken into account:

The closer the distance, the clearer and sharper the visible object seems to us;

The closer an object is, the larger it appears;

Larger objects appear closer than small objects located at the same distance;

A brighter colored object appears closer than a dark colored object;

Brightly lit objects appear closer to dimly lit ones at the same distance;

During fog, rain, twilight, cloudy days, when the air is saturated with dust, observed objects seem further away than on clear and sunny days;

The sharper the difference in color between the object and the background against which it is visible, the more reduced the distances appear; for example, in winter a snow field seems to bring the darker objects on it closer;

Objects on flat terrain seem closer than on hilly terrain, distances defined across vast expanses of water seem especially shortened;

Folds of the terrain (river valleys, depressions, ravines), invisible or not fully visible to the observer, conceal the distance;

When observing while lying down, objects appear closer than when observing while standing;

When observed from the bottom up - from the base of the mountain to the top, objects appear closer, and when observed from top to bottom - further away;

When the sun is behind the scout, the distance disappears; shines into the eyes - it seems larger than in reality;

The fewer objects there are in the area under consideration (when observed through a body of water, a flat meadow, steppe, arable land), the shorter the distances seem.

The accuracy of the eye gauge depends on the intelligence of the scout. For a distance of 1000 m, the usual error ranges from 10-20%.

By linear dimensions. To determine the distance using this method, you need to:

Hold a ruler in front of you at arm's length (50-60 cm from the eye) and use it to measure in millimeters the apparent width or height of the object to which you want to determine the distance;

Divide the actual height (width) of an object, expressed in centimeters, by the apparent height (width) in millimeters, and multiply the result by 6 (a constant number), to obtain the distance.

For example, if a pole 4 m (400 cm) high is closed along an 8 mm ruler, then the distance to it will be 400 x 6 = 2400; 2400:8 = 300 m (actual distance).

To determine distances in this way, you need to know well the linear dimensions of various objects, or have this data at hand (on a tablet, in a notebook). The reconnaissance officer must remember the dimensions of the most frequently encountered objects, since they are also required for the method of measuring by angular value, which is for reconnaissance

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By visibility (discernibility) of objects. With the naked eye, you can approximately determine the distance to targets (objects) by the degree of their visibility. A scout with normal visual acuity can see and distinguish some objects from the following maximum distances,

indicated in the table. It must be borne in mind that the table indicates the maximum distances from which certain objects begin to be visible.

For example, if a scout saw a pipe on the roof of a house, then this

means that the house is no more than 3 km away, and not exactly 3 km. It is not recommended to use this table as a reference. Each intelligence officer must individually clarify this data for himself. When determining distances by eye, it is advisable to use landmarks whose distances are already precisely known.

By angular value. To apply this method, you need to know the linear size of the observed object (its height, length or width) and the angle (in thousandths) at which this object is visible. For example, the height of a railway booth is 4 meters, the scout sees it at an angle of 25 thousandths (the thickness of a little finger). Then

Measuring distance is one of the most basic tasks in geodesy. There are different distances, as well as a large number of devices created to carry out this work. So, let's look at this issue in more detail.

Direct method for measuring distances

If you need to determine the distance to an object in a straight line and the area is accessible for research, use such a simple device for measuring distance as a steel tape measure.

Its length is from ten to twenty meters. A cord or wire can also be used, with white markings after two and red after ten meters. If it is necessary to measure curved objects, the old and well-known two-meter wooden compass (fathom) or, as it is also called, “Kovalyok”, is used. Sometimes it becomes necessary to make preliminary measurements of approximate accuracy. They do this by measuring the distance in steps (at the rate of two steps equal to the height of the person measuring minus 10 or 20 cm).

Measuring distances on the ground remotely

If the measurement object is in the line of sight, but in the presence of an insurmountable obstacle that makes direct access to the object impossible (for example, lakes, rivers, swamps, gorges, etc.), distance measurement is used remotely by the visual method, or rather by methods, since there is There are several varieties of them:

1. High precision measurements.
2. Low precision or approximate measurements.

The first includes measurements using special instruments, such as optical rangefinders, electromagnetic or radio rangefinders, light or laser rangefinders, ultrasonic rangefinders. The second type of measurement includes a method called geometric eye measurement. This includes determining distances based on the angular size of objects, constructing equal right-angled triangles, and the method of direct notching in many other geometric ways. Let's look at some of the methods for high-precision and approximate measurements.

Optical distance meter

Such distance measurements with millimeter accuracy are rarely needed in normal practice. After all, neither tourists nor military intelligence officers will carry large and heavy objects with them. They are mainly used when carrying out professional geodetic and construction work. A distance measuring device such as an optical range finder is often used. It can be either with a constant or variable parallax angle and can be an attachment to a regular theodolite.

Measurements are made using vertical and horizontal measuring rods that have a special installation level. of such a rangefinder is quite high, and the error can reach 1:2000. The measurement range is small and ranges only from 20 to 200-300 meters.

Electromagnetic and laser rangefinders

An electromagnetic distance meter belongs to the so-called pulse-type devices; the accuracy of their measurement is considered average and can have an error of 1.2 to 2 meters. But these devices have a great advantage over their optical counterparts, since they are optimally suited for determining the distance between moving objects. Their units of distance measurement can be calculated in both meters and kilometers, so they are often used when carrying out aerial photography.

As for the laser rangefinder, it is designed to measure not very large distances, has high accuracy and is very compact. This especially applies to modern portable devices. These devices measure the distance to objects at a distance of 20-30 meters and up to 200 meters, with an error of no more than 2-2.5 mm over the entire length.

Ultrasonic range finder

This is one of the simplest and most convenient devices. It is lightweight and easy to operate and refers to devices that can measure the area and angular coordinates of a single specified point on the ground. However, in addition to the obvious advantages, it also has disadvantages. Firstly, due to the short measuring range, the distance units of this device can only be calculated in centimeters and meters - from 0.3 to 20 meters. Also, the accuracy of the measurement may change slightly, since the speed of sound directly depends on the density of the medium, and, as is known, it cannot be constant. However, this device is great for quick, small measurements that do not require high precision.

Geometric eye methods for measuring distances

Above we discussed professional methods of measuring distances. What to do when you don’t have a special distance meter at hand? This is where geometry comes to the rescue. For example, if you need to measure the width of a water barrier, you can build two equilateral right triangles on its shore, as shown in the diagram.

In this case, the width of the river AF will be equal to DE-BF. Angles can be adjusted using a compass, a square piece of paper, or even using identical crossed branches. There shouldn't be any problems here.

You can also measure the distance to the target through an obstacle by also using the geometric straight-line method, constructing a right triangle with the vertex on the target and dividing it into two scalene triangles. There is a way to determine the width of an obstacle using a simple blade of grass or thread, or a method using an extended thumb...

It is worth considering this method in more detail, since it is the simplest. On the opposite side of the obstacle, a noticeable object is selected (you must know its approximate height), one eye is closed and the raised thumb of an outstretched hand is pointed at the selected object. Then, without removing your finger, close the open eye and open the closed one. The finger turns out to be shifted to the side in relation to the selected object. Based on the estimated height of the object, it is approximately how many meters the finger has visually moved. This distance is multiplied by ten to obtain the approximate width of the obstacle. In this case, the person himself acts as a stereophotogrammetric distance meter.

There are many geometric ways to measure distance. It would take a lot of time to talk about each one in detail. But they are all approximate and are only suitable for conditions where accurate measurement with instruments is impossible.