Determination of the standing point. Determining your standing point and target designation on the ground How to determine your standing point on the map

Section 5. Location orientation

§ 1.5.1. Essence and methods of orientation

Terrain orientation includes determining one’s location relative to the sides of the horizon and prominent terrain objects (landmarks), maintaining a given or chosen direction of movement and understanding the location of landmarks, boundaries, friendly troops, enemy troops, engineering structures and other objects on the ground.

Methods of orientation. Depending on the nature of the task being performed, orientation can be carried out on the spot from individual points (for example, from observation points during reconnaissance) or on the move (on the march, on the offensive, etc.). In both cases, the main method is to navigate using a topographic map using a compass.

Reliable route keeping in difficult conditions and poor visibility is most successfully carried out using a topographic map using data provided by navigation equipment (coordinator and course plotter). A generally available way to maintain the direction of movement at night, as well as in areas with rare landmarks, is to move along azimuths prepared in advance from the map. In some cases, orientation (determining the direction of movement) can be done without a map (using a compass, landmarks, celestial bodies, signs of local objects).

When orienting on the ground during reconnaissance, topographical and then tactical orientation is performed first.

Topographical orientation includes determining the sides of the horizon, the point of one’s standing, and the position of surrounding terrain objects. When doing topographical orientation, they first show the direction to the north of any object and their location relative to the nearest and clearly visible landmark. Then the necessary landmarks and other terrain objects are named, directions to them and approximate distances are indicated. Directions to landmarks indicate relative to your position (straight, right, left) or along the sides of the horizon. The order of indicating landmarks is from right to left, starting from the right flank. Example of a report on topographical orientation: “ The direction to the north is the mound. We are located on the northern outskirts of Timonovka; on the right, 5 km - Semenovka; straight ahead, 4 km - “Dark” grove; further, 10 km - the settlement of Ivanovka; to the left, 2 km - height 125.6».

Tactical orientation consists of determining and showing on the ground the location and nature of the actions of enemy troops and friendly units by a certain time.

§ 1.5.2. Navigation without a map

Orientation without a map consists of determining the sides of the horizon (directions north, east, south, west) and your location on the ground relative to landmarks and takes place in a limited area.

Landmarks are clearly visible local objects and relief details, relative to which they determine their location, direction of movement and indicate the position of targets and other objects.

Landmarks are chosen as evenly as possible along the front and in depth. The selected landmarks are numbered from right to left along the lines and away from you towards the enemy. In addition to the number, each landmark is usually given a conventional name corresponding to its external characteristics, for example, “ Dry wood», « House with a red roof" and so on.

Sides of the horizon and methods for determining them

It must be remembered that if you stand facing north, then the east will be on your right hand, the west will be on your left, respectively, the south will be behind your back . To determine the sides of the horizon, the following methods can be recommended:

• by compass;
• by the Sun and analogue clock;
• by the Sun and digital clock;
• using improvised means;
• for local facilities;
• according to the North Star;
• on the Moon.

Let us consider in more detail the indicated methods for determining the sides of the horizon, as well as the recommended sequence of their development during training sessions.

Determining the sides of the horizon using a compass . A magnetic compass is a device that allows you to determine the sides of the horizon, as well as measure angles in degrees on the ground. The principle of operation of a compass is that a magnetized needle on a hinge rotates along the lines of force of the Earth's magnetic field and is constantly held by them in one direction. The most common are various versions of the Adrianov compass and the artillery compass.

Rice. 5.1 Compass Adrianov

1 - cover with stands for sighting; 2 - limb; 3 - count indicator; 4 – magnetic needle; 5 - brake

Compass Adrianov(Fig. 5.1) allows you to measure angles in degrees and inclinometer divisions. A dial with two scales is used to measure angles. Degrees are marked in 15° intervals (division value is 3°) clockwise, protractor divisions are marked in 5-00 intervals (division value is 0-50). The dial reading is read using a pointer mounted on the inner wall of the compass cover opposite the front sight. The northern end of the magnetic needle, the reference and division indicator on the dial, corresponding to 0°, 90°, 180° and 270°, are covered with a glow-in-the-dark composition. There is a mechanism that slows down the movement of the arrow.

Rice. 5.2 Artillery compass

1 – compass body; 2 – rotating dial body; 3 - limb; 4 – compass cover with a mirror “a”, a cutout for sighting “b” and a latch “c”; 5 – magnetic needle; 6 – protrusion of the brake lever arrows

Artillery compass(Fig. 5.2) thanks to some improvements, it is more convenient to use than Adrianov’s compass. Its body is rectangular, which allows you to accurately position the compass along the map lines and draw directions. The compass cover with a mirror surface allows you to observe the position of the magnetic needle and at the same time sight the object. The magnetic needle more steadily records the direction of the magnetic meridian; Its braking is carried out by closing the lid. The scale division value is 1-00, their signatures are given after 5-00 clockwise.

Determining the sides of the horizon using the Sun and an analog clock . This fairly convenient and accurate method of determining the sides of the horizon is used if the Sun is visible, or it is determined through the clouds.

Analog watches are held in a horizontal plane and rotated until the hour hand aligns with the direction of the Sun, the position of the minute hand is not taken into account. The angle between the hour hand and the number “1” on the watch dial is divided in half. A line dividing this angle in half will indicate the direction to the south (Fig. 5.3). It is important to remember that before one o'clock in the afternoon the angle not traversed by the clock hand is divided in half, and after one o'clock in the afternoon - the angle which it has already passed.

Determining the sides of the horizon using the Sun and a digital clock . This method of determining the sides of the horizon is used when the light of the Sun is sufficient for objects to cast a shadow.

On a horizontal surface (on the ground) a circle with a diameter of 25-30 cm is drawn with a point in the center. Then, on the outer side of the circle from the side of the Sun, a small load (for example, a bunch of keys) is suspended on a rope or cord so that the shadow of the rope passes through the center of the drawn circle. Next, through the point of intersection of the shadow from the rope with the sunny side of the circle and the center of the circle, a radius is drawn, indicating the hour hand of an imaginary clock. Using a digital clock, the actual time is specified, according to which divisions of an imaginary dial are drawn in the circle.

Further, as on an analog watch, the angle between one o'clock in the afternoon and the drawn hour hand is divided in half (before one o'clock in the afternoon the angle not passed by the hour hand is divided in half, and after one o'clock in the afternoon - the angle which it has already passed). The resulting direction is south (Fig. 5.4).

Rice. 5.4 Determining the sides of the horizon using the Sun and a digital clock

Determining the sides of the horizon using available tools . The situation becomes more complicated when on a cloudy day it is impossible to determine exactly where the Sun is. However, even in this case, there are ways to fairly accurately determine the sides of the horizon.

Rice. 5.5 Determining the sides of the horizon using a float and a needle

A flat round float with a diameter of 15-20 mm and a thickness of 5-6 mm is made from bark or a piece of wood. A shallow diametrical cut is made on the float, into which it is necessary to carefully place the needle and lower the float onto the existing water surface (any puddle; water poured into a plastic or wooden container; a small depression in the ground, lined with a plastic bag and filled with water from a flask, etc. ). Under the influence of earthly magnetism, the needle will certainly turn and, swinging between east and west, will be positioned with its tip to the north and its ear to the south, that is, along the magnetic force lines of the Earth (Fig. 5.5).

If there is no needle, then a thin steel nail or steel wire can replace it. But in this case, it is important to remember that the needle turns with its tip to the north due to the peculiarities of the manufacturing technology - the so-called “broaching”. With a piece of wire or a nail, the direction of pulling is unknown; therefore, it is unclear which end points to the north and which to the south. Therefore, for alignment, it is necessary to perform the same operations once near a noticeable landmark (anthill, growth rings, etc.) as with a needle, then mark the end of the wire or nail that will turn to the north. Interesting fact: even an automatic cleaning rod on a float of the appropriate size can play the role of a compass needle - the cleaning rod will always turn to the north with a thread (true only for AKs manufactured before 1984).

Determining the sides of the horizon using local objects . The sides of the horizon can be determined by local objects, but it must be remembered that the error in this case may be 15-20°.

• One of the most reliable indicators of the sides of the horizon are forest anthills - they are usually located at the roots of a tree with a thick crown that protects them from rain and always on the southern side of this tree. In addition, the southern side of the anthill is always flatter compared to the northern.
• The next, albeit not as reliable indicator as an anthill, is moss on stones and trees. Moss, avoiding direct sunlight, grows on the shady northern sides of stones and trees. Using this method, you need to be careful: since there is no direct sunlight in a dense forest, moss grows around the entire surface of the tree - at its roots and above. The same goes for stones. Accordingly, this method “works” well only on isolated trees or stones. Or, as a last resort, in open forests.
• The sides of the horizon can be determined by the annual rings of trees. To do this, you can find a free-standing stump or cut a small, free-standing tree with a diameter of 70-80 mm. Having carefully cleaned the cut, we will see that the core, that is, the center of the concentric annual rings, is shifted relative to the geometric center of the stump, and it is necessarily shifted to the north. By drawing a straight line through the geometric center of the stump and the center of the concentric annual rings, we get the direction to the north.
• The bark of most trees is coarser on the north side, thinner, more elastic (birch is lighter) on the south.
• In pine, the secondary (brown, cracked) bark on the north side rises higher along the trunk.
• On the north side, trees, stones, wooden, tiled and slate roofs are covered earlier and more abundantly with lichens and fungi.
• On coniferous trees, resin accumulates more abundantly on the south side.
• In spring, the grass cover is more developed on the northern outskirts of the meadows, warmed by the sun's rays, and in the hot period of summer - on the southern, darkened ones.
• Berries and fruits acquire the color of maturity earlier (turn red, turn yellow) on the south side.
• In summer, the soil near large stones, buildings, trees and bushes is drier on the south side, which can be determined by touch.
• Snow melts faster on the southern sides of snowdrifts, resulting in the formation of notches in the snow - spikes directed to the south.
• In the mountains, oak often grows on the southern slopes.
• Clearings in forests are usually oriented in the north-south or west-east direction.
• The altars of Orthodox churches, chapels and Lutheran kirks face east, and the main entrances are located on the west side.
• The altars of Catholic churches (cathedrals) face west.
• The raised end of the lower crossbar of the church cross faces north.
• Kumirni (pagan chapels with idols) face south.
• On Christian graves, the gravestone or cross stands at the feet, that is, on the east side, since the grave itself is oriented from east to west.

Determining the sides of the horizon by the North Star . Let us recall the remarkable property of the Polar Star - it is practically motionless during the daily rotation of the starry sky and, accordingly, is very convenient for orientation - the direction towards it practically coincides with the direction to the north (the deviation from the north point does not exceed 3°).

To find this star in the sky, you must first find the constellation Ursa Major, which consists of seven fairly noticeable stars located so that if you connect them with an imaginary line, a bucket will be drawn.

If you mentally continue the line of the front wall of the bucket, approximately 5 distances equal to the length of this wall, then it will rest against the North Star (Fig. 5.6).

If you are in the mountains or in the forest, you may not see the bucket if it is currently located under the North Star. In this case, another noticeable constellation will help - the Constellation Cassiopeia. This constellation is formed by six fairly bright stars and represents the Russian letter “Z” when located to the right of the North Star, and the irregular letter “M” when located above the North Star.

Rice. 5.6 Finding the North Star in the sky

To find the North Star, you need to mentally draw a median from the top of the large triangle of the constellation (i.e., a straight line connecting the top of the triangle with the middle of the opposite side) to its base, which, when continued, will rest against the North Star (Fig. 5.6).

Determining the sides of the horizon by the Moon . The sides of the horizon are determined on a cloudy night, when it is not possible to find the North Star. To do this, you need to know the location of the Moon in various phases (Table 5.1)

The table shows that it is most convenient to determine the sides of the horizon during the full moon. In this phase, the Moon is at any time in the direction opposite to the Sun.

Table 5.1

§ 1.5.3. Movement in azimuths

Movement along azimuths is a method of maintaining the intended path (route) from one point (landmark) to another along known azimuths and distances. Movement along azimuths is used at night, as well as in the forest, desert, tundra and in other conditions that make it difficult to navigate on the map.

Determining the direction on the ground at a given azimuth using Adrianov's compass . By rotating the compass cover, the pointer is set to a reading corresponding to the value of the specified azimuth. Then, having freed the magnetic needle, turn the compass so that the zero stroke of the dial aligns with the northern end of the needle. At the same time, they stand facing the desired direction and, raising the compass to approximately shoulder level, sight along the slot-front sight line and notice some landmark on the ground in this direction. This direction will correspond to the specified azimuth.

Determining the direction on the ground at a given azimuth using an AK artillery compass . The compass cover is set at an angle of 45° and by rotating the dial, the given reading is aligned with the pointer at the slot in the cover. The compass is raised to eye level and, observing in the lid mirror, is turned until the zero stroke of the dial aligns with the northern end of the arrow. In this position of the compass, one sights through the slot and notices any landmark. The direction to the landmark will correspond to the specified azimuth.

Measuring magnetic azimuth with Adrianov's compass . Having freed the magnetic needle, turn the compass to draw a zero stroke under the northern end of the needle. Without changing the position of the compass, by rotating the ring, direct the sighting device with the front sight towards the object to which you want to measure the azimuth. Aiming the front sight at an object is achieved by repeatedly moving the gaze from the sighting device to the object and back; For this purpose, you should not raise the compass to eye level, since this may cause the needle to move away from the zero stroke of the dial and the accuracy of azimuth measurement will sharply decrease. Having aligned the sighting line of the front sight slot with the direction towards the object, take a count from the front sight pointer. This will be the azimuth of the direction to the object. The average error in measuring azimuth with Adrianov's compass is 2-3°.

Measuring magnetic azimuth with an AK artillery compass . Having placed the compass cover at approximately an angle of 45?, sight the object. Then, without changing the position of the compass, by rotating the dial, observing in the mirror, bring the zero stroke of the dial to the northern end of the magnetic needle and take a reading from the pointer. The average error in measuring azimuth with an AK artillery compass is approximately 0-25.

Preparing data for azimuth movement . The route is marked on the map with clear landmarks at turns and the directional angle and length of each straight section of the route are measured. Directional angles are converted into magnetic azimuths, and distances are converted into pairs of steps if the movement is on foot, or into speedometer readings when marching in cars. Data for movement along azimuths is drawn up on the map, and if there is no map on the way, then draw up a route diagram (Fig. 5.7) or a table (Table 5.2).

Rice. 5.7 Route diagram for movement in azimuths

Landmark number and name	Magnetic azimuth, degrees	Distance
		in meters	in a couple of steps
1 – separate yard	-	-	-
2 – the place where the road enters the forest	15	1557	1038
3 – intersection of clearings	330	645	430
4 – hole near the clearing	356	1020	680
5 – forester’s house	94	705	470

Table 5.2

Order of movement by azimuths . At the initial (first) landmark, using a compass, the direction of movement to the second landmark is determined by azimuth. They notice some distant landmark (auxiliary) in this direction and begin to move. Having reached the intended landmark, they again mark the direction of movement using the compass to the next intermediate landmark and so continue moving until they reach the second landmark.

In the same order, but in a different azimuth, they continue moving from the second landmark to the third, etc. On the way, taking into account the distances covered, they look for landmarks at the turns of the route and thereby control the correctness of the movement.

To make it easier to maintain the direction, you should use the celestial bodies and various signs: the straightness of a walking column or your own track when skiing, the direction of ripples in the sand and sastrugi in the snow (sastruga is a long and narrow snow bank swept by the wind), wind direction, etc. Based on the celestial bodies, you can confidently maintain the direction of movement, clarifying it with a compass approximately every 15 minutes.

The accuracy of reaching a landmark depends on the accuracy of determining the direction of movement and measuring the distance. Deviation from the route due to the error in determining the direction using a compass usually does not exceed 5% of the distance traveled. If the direction of movement is clarified by the compass often enough, then the deviation from the route will be about 3% of the distance traveled.

Avoiding Obstacles . If there are obstacles on the route, then detour routes are marked on the map and the necessary data is prepared for this - azimuths and distances. Obstacles not taken into account when preparing data for movement are avoided in one of the following ways.

First way is used when the obstacle is visible to the end. In the direction of movement, mark a landmark on the opposite side of the obstacle. Then they go around the obstacle, find the noticed landmark and continue moving from it in the same direction; The width of the obstacle is estimated by eye and added to the distance traveled to the obstacle.

Second way. An obstacle, the opposite side of which is not visible, is walked around in directions forming a rectangle or parallelogram, the azimuths and lengths of the sides of which are determined on the ground. An example of such a bypass is shown in Fig. 5.8. From point A walk along the obstacle in the selected direction (in the example - in azimuth 280°). Having passed to the end of the obstacle (to the point IN) and having measured the resulting distance (200 pairs of steps), they continue moving along the given azimuth (in the example - along the 45° azimuth) to the point WITH. From point WITH enter the main route in the opposite direction azimuth AB(in the example - in azimuth 100°, since the reverse azimuth is equal to the forward azimuth ±180°), measuring 200 pairs of steps in this direction (distance CD , equal AB). Here is the line length Sun added to the distance traveled from point No. 2 to point A, and continue moving to point No. 3.

§ 1.5.4. Orientation on the map

Orientation at a location includes orienting a map, identifying landmarks, determining a standing point, and comparing the map with the terrain.

Orienting a map is giving it, by rotating it in a horizontal plane, a position in which the north side of the frame faces north, and the lines and directions on the map are parallel to the corresponding lines and directions on the ground. The map is oriented by a compass, terrain line or direction to a landmark.

Orienting the map using a compass . The technique is used mainly in terrain that is difficult to navigate (in a forest, desert, etc.). Under these conditions, the compass is used to determine the direction to the north, and then the map is turned with the top side of the frame in this direction. The compass map can be oriented more accurately taking into account magnetic declination. In this case, a compass with an open magnetic needle is installed on one of the vertical lines of the map coordinate grid so that the line passing through the 0 and 180° strokes of the scale (or the corresponding edge of the AK compass) coincides with the map line. The map is then rotated so that the north end of the magnetic needle deviates from the 0° line by the amount of direction correction indicated in the lower left corner of the given map sheet. An example of map orientation using a compass is shown in Fig. 5.9.

Rice. 5.9 Orienting the map using a compass

Orienting the map along the terrain line . The map is rotated so that the line of the symbol of a local object, for example a road, coincides with the direction of the local object itself, and the images of all objects located to the right and left of it are located on the same sides as on the ground (Fig. 5.10).

Rice. 5.10 Orienting the map along the terrain line

Orienting the map by towards a landmark . The technique is used when the standing point is known and the landmark marked on the map is visible from it. The map is rotated so that the direction “standing point - landmark” coincides with the corresponding direction on the ground. For more accurate orientation of the map, apply a ruler to these points and use it to sight the landmark.

Landmark identification - the most critical stage of orientation on the map, since the standing point can only be determined by landmarks, common to the map and the area.

Identification of landmarks begins with the largest, most prominent objects in the area, and those that are relatively rare in a given area. When searching for objects observed on the map on the map, their relative position and position relative to the sides of the horizon are taken into account. The correct identification of landmarks is checked using the surrounding elements of the terrain.

In cases where it is not possible to identify landmarks that are common to the map and the area, you should move so that other landmarks become visible and try to identify these landmarks on the map.

Determining the standing point on the map is done by eye using the nearest landmarks, measuring distances, measured distances and directions, and resection. When choosing a method, the nature of the terrain, visibility conditions, time availability, as well as the accuracy with which it is desirable to determine the standing point are taken into account.

Determining the standing point on the map by eye It is recommended to determine the standing point using the nearest landmarks on moderately rough terrain, when the point is located near a terrain feature shown on the map. To do this, they orient the map, identify two or three nearest landmarks on it and determine the distances to them by eye. Based on certain distances to landmarks, taking into account directions, a standing point is marked on the map. The accuracy of determining a standing point on a map using this method depends mainly on the distances to landmarks: what are these The longer the distance, the less reliably the standing point is determined. When located from landmarks at a distance of up to 500 m, the standing point, with sufficient experience, is determined with an average error of the order of 20% of the average distance to landmarks.

Determining a standing point on a map by measuring the distance . The method is used mainly when driving on a road or along a linear contour, mainly in closed areas or under poor visibility conditions. The essence of the method: measure the distance (for example, in steps) from a landmark located near the road or some other linear landmark to a designated standing point; then this distance is plotted on the map along the road (linear landmark) in the appropriate direction. The accuracy of determining the standing point using this method depends mainly on the magnitude of the error in measuring the distance on the ground.

Determining a standing point on a map by direction and distance . The method is used when only one landmark is identified. In this case, the map is oriented according to the compass, taking into account the magnetic declination. Then apply a ruler to a landmark on the map, aim it at the same landmark on the ground and draw a line (Fig. 5.11- A). You can also sight using a pencil mounted vertically (Fig. 5.11- b).

Rice. 5.11 Sighting techniques:

a – along a ruler;
b – by pencil

To do this, the oriented card should be in a horizontal position at approximately chin level. The pencil is placed vertically on the image of a landmark on the map, they are sighted through it at the landmark and, without changing the position of the eye and the map, they slowly move the pencil towards themselves. On the drawn line of sight from the landmark image, a distance is set aside, which is previously measured by steps, binoculars, rangefinder, or estimated by eye. Under the same conditions, the standing point can be determined using another technique (Fig. 5.12).

Rice. 5.12 Determining the standing point by direction and distance

At the standing point, measure the magnetic azimuth to the landmark with a compass. Then this azimuth is converted to the reverse (add or subtract 180°), and the last - to the directional angle along which a direction is drawn from a landmark on the map and the measured distance is plotted along this direction. The resulting point will be the desired standing point.

Example . The magnetic azimuth to the landmark (geodetic point) is 30°, the distance is 1500 m, the correction to the magnetic azimuth when moving to the directional angle is +12°. Determine the standing point. Solution. The return azimuth is 210° (30° + 180°), the directional angle is 222° (210° + 12°); the necessary constructions are shown in Fig. 5.12.

The average error in determining the standing point by distance and direction is about 5% of the distance from the standing point to the landmark when measuring distance in steps and azimuth with a compass.

Determining the standing point on the map by resection in one direction . This method is used when you are on a road (or other linear object), from which only one landmark is visible, located to the side of it. The map is oriented as accurately as possible and sighted on a landmark. The intersection point of the hairline and the road will be the desired standing point. The standing point under the same conditions can be determined by the following method: measure the magnetic azimuth to the landmark, convert it to the opposite one, and convert the latter into a directional angle. Based on the value of the directional angle, the direction from the landmark to the intersection with the road is drawn.

The average error in determining the standing point using this method, when carefully performing the techniques, is about 10% of the range at the notching angle from 30 to 60° and from 120 to 150° and about 5% at the notching angle from 60° to 120°.

Determination of the standing point on the map by resection in three (two) directions . This method is used mainly in open areas, poor in landmarks, when three (at most two) landmarks are identified. If possible, you should use landmarks located closer to the standing point so that the directions from the landmarks at the standing point intersect at angles within 30-150°.

Rice. 5.13 Determining the standing point by resection

The map is carefully oriented using a compass, a ruler is applied to the symbol of one of the landmarks on the map and directed to the same landmark on the ground, then a line is drawn towards yourself (Fig. 5.13). Without confusing the orientation of the map, the directions to the second and third landmarks are drawn in the same way. The intersection of three directions usually forms a triangle, the center of which will be the standing point. In two directions, the standing point is determined less accurately, and most importantly, without control.

Under the same conditions, when working with the map is difficult (it is raining, etc.), the standing point can be determined by magnetic azimuths measured from the standing point to landmarks. Magnetic azimuths are converted into reverse ones, and the latter into directional angles, and directions on the map from the corresponding landmarks are drawn using them.

The average error in determining the standing point by resection using three landmarks is about 15% of the average distance to the landmarks.

Comparison of the map with the terrain - the final stage of topographic orientation. At this stage, the terrain is studied, its changes that have occurred since the creation of the map are identified, and the location of the objects shown on the map is clarified.

To find an object visible on the map on the map, mentally or using a ruler, draw a line from the standing point to the terrain object and, in the direction of this line, find the symbol of the object being sought or make sure that the object is not shown on the map. To more accurately determine the direction to an object, measure the magnetic azimuth to it using a compass, calculate the directional angle of this direction, and use its value to draw the direction on the map.

To solve the inverse problem, i.e. to identify an object on the ground, indicated on the map, mentally or using a ruler, sight along the line connecting the standing point and the symbol of the object, and in this direction, taking into account the distance to the desired object, search for it on the ground.

Map navigation on the move . Depending on the nature of the terrain, when orienting on the move, they usually use a map at a scale of 1:100000 or 1:200000. The main task of orienteering in motion is to maintain a given route or one outlined on the map. Orientation while moving is carried out continuously in order to constantly know your location on the map, which is determined visually by comparing the map with the terrain. To do this, prepare a map in advance, and follow a certain order along the way.

§ 1.5.5. Creating a raster map

To create a raster map we will use the SASPlanet program.

Initially, you need to find the area of ​​interest by scrolling the map. Do not pay attention to the highlighted rectangle - this is a trace of the previous search (it will disappear when starting a new search).

Having selected the area of ​​interest at the desired scale, you need to click on “select rectangle”.

Rice. 5.14 Search for a site

Move the mouse pointer to the map field (upper left corner) and left-click once (this sets one of the corners of the rectangle); move the mouse pointer diagonally down the screen without pressing a key; Having outlined the desired rectangle, click the left mouse button; The Selected Area Operations dialog box appears.

Rice. 5.20 Specifying a card name

Click the “Start” button, wait for the end of saving the map piece, exit the SASPlanet program.

Rice. 5.21 Starting the saving process

Rice. 5.22 Saving process

Measuring angles and directions using a topographic map. True azimuth A, magnetic azimuth A M and directional angle b of a given line can be measured on a map using a protractor. For the convenience of measuring these quantities on domestic topographic maps, under the bottom frame of the sheet to the left of the linear scale, a graph is placed showing the relative positions of the geographical, magnetic meridians and vertical grid lines, and also indicates, with an accuracy of up to a minute, the average declination of the magnetic needle, the Gaussian convergence of the meridians and the annual change magnetic declination.

Directional angle b is the angle between the northern direction of the vertical line of the kilometer grid and the direction towards the object; it is measured clockwise (on the map - with a protractor).

Determination of directional angles and magnetic azimuths from the map. Measure or construct directional angles on a map using a protractor. To measure the directional angle of any direction, you need to draw this direction on the map with a sharpened pencil (Fig. 5). Next, you need to figure out which quarter this direction is located in and what the approximate value of the angle will be. Then the protractor is placed on the map so that the middle of its ruler, marked with a stroke, coincides with the point of intersection of this direction and one of the vertical lines of the coordinate grid, and the edge of the protractor ruler aligns with this line. After this, the angle corresponding to the rumba or directional angle is measured on the protractor scale. For line AB (see Fig. 5) the directional angle is 43°00"; since the eastern declination is 6° 15", and the western approach is 2°21", then the correction to the directional angle when transitioning to magnetic azimuth

A M = b-(g+d) = 43°00" - (6°15" + 2°21") = 34°24".

Rice. 1.

For the IR line, the directional angle is 228°00", and the magnetic azimuth

A M = b-(g+d) = 228°00" - (6°15" + 2°21") = 219°24".

In Figure 1, the directions AB, ..., DE are straight. For them, directional angles b are measured, and magnetic azimuths A M are calculated similarly to the direction AB. Directions E, IR are reverse, so the directional angle is measured as for the IR direction.

To construct a directional angle on a map, a straight line is drawn through a given point, parallel to the vertical line of the coordinate grid. Then a protractor is applied to this line so that its middle coincides with this point, and this angle is plotted on the protractor scale. Determination of the standing point. The easiest way to determine the standing point is when it is located near any local object shown on the map. Let's say we are on the highway at a railroad crossing. Find on the map an image of the railway and highway. The intersection of the axes of the road and railway symbols will indicate the standing point. It is somewhat more difficult to determine the standing point in a place where there are no local objects nearby. In such cases, various serif methods are used. The most common way is as follows. Two noticeable objects (landmarks) are found on the ground and identified on the map. Then the map is oriented with the help of a compass as accurately as possible and the direction is drawn on it from the objects themselves through their symbols. The point of intersection of these directions will be the standing point (Fig. 2).

Rice. 2.

Rice. 3. Sighting with a pencil: a-- a pencil is placed on the map; 6- the pencil is positioned vertically

The direction on the map from the landmark to the standing point can be marked by sighting. In the field, sighting is usually done using a pencil placed on the map. They do it like this. Orient the map and apply a pencil to the symbol of the landmark (Fig. 3, a). Gradually turn the pencil around the symbol and sight it at the landmark. When the landmark is on the line of sight, and the edge of the pencil touches it conditionally.

Rice. 4. Identification of a distant local object on the map: a - terrain; b-- map of the th sign, draw a line from the landmark towards yourself.

In addition, sighting can be done using a pencil located vertically (Fig. 3, b). The card is oriented and raised to shoulder height. The pencil is placed vertically on the conventional landmark and the object is sighted through it. Then, without changing the position of the eye and the card, they slowly move the pencil towards themselves - it will draw the direction from the object to the standing point.

Main part

Study question No. 1. Orientation on the map. Determination of azimuths to local objects.

Orientation on the map.

The map is the main means of orientation. A topographic map has been and remains a reliable guide to unfamiliar terrain. Using a map, you can quickly and accurately determine your location, indicate detected targets, and confidently follow a given or intended route.

Orientation on the map includes orientation of the map, comparing it with the terrain and determining your location (standing point).

Map orientation.

Orienting a map means positioning it horizontally so that the north (top) side of the map frame faces north. With this position of the map, the location of local objects and landforms on the ground will correspond to the location of symbols on the map.

Orientation of the map can be done according to a linear landmark or direction to a landmark, when your location (standing point) is known in advance on the map. If the standing point is unknown, the map is oriented along the sides of the horizon.

By linear reference the map can be oriented roughly or precisely.

In this case, their location on the map is also determined approximately, by eye.

For precise orientation cards use a ruler or pencil. By attaching a ruler to a conventional sign of a linear landmark, for example a road, its direction is aligned with the direction of this landmark on the ground. Then they check whether all local objects and landforms located on the ground to the right and left of the road have the same location on the map. If this condition is met, the map is oriented correctly.

The map is oriented towards a landmark in the same way as towards a linear landmark. The only difference is that instead of a linear landmark, they use the direction from the standing point to some distant local object (a separate tree, bridge, repeater, i.e., a point landmark), reliably identified on the ground and on the map.

When roughly orienting a map using this method, it is turned in a horizontal position so that the direction mentally drawn on the map from the standing point to the symbol of a local object approximately coincides with this direction on the ground.

Precise orientation of the map in the direction of a distant local object (landmark) is performed using a sight ruler or pencil.

Accurate map orientation towards a landmark Accurate orientation of the map using the compass: a – the compass is installed on a vertical grid line; b – the compass is installed on the side (western) frame of the map

The ruler is applied on the map with its side edge to the standing point (a separate stone) and the symbol of the object in the direction of which the map is oriented (a railway bridge). Then turn the map horizontally so that the object on the ground is on the line of sight. In this position the map will be oriented accurately. The map is oriented using a compass when one’s location on it is not determined or landmarks are not visible from the standing point. When roughly orienting a map, first determine the direction to the north using a compass, then turn the map so that the top side of the frame faces north. When accurately orienting a map using a compass, first the compass reference pointer is set against a scale division equal to the direction correction if the compass is installed on a vertical line of the kilometer grid, or the magnetic declination value if the compass is installed on the western or eastern side of the map frame. If the direction correction (magnetic declination) is positive (eastern), the reference pointer is set to the right of the zero scale division, and if negative (western) - to the left.

Then the compass is installed on the map so that the zero diameter of its limb coincides with one of the vertical lines of the coordinate grid or with one of the sides of the map frame (west or east), and the northern end of the magnetic needle is directed to the north side of the map frame. Without changing the position of the compass, the map is turned horizontally until the northern end of the magnetic needle is set opposite the reading that was previously set on the scale.

If the direction correction (or magnetic declination) is less than 3°, i.e. equal to the compass scale division, it is not taken into account when orienting the map.

Determining your standing point on the map.

The standing point can be determined on the map in various ways: by the nearest landmarks by eye, by measuring the distance traveled and by notching.

If the standing point on the ground is located next to any local object or its characteristic bend (turn) shown on the map, then the location of the symbol (turning point) of this object will coincide with the desired standing point.

Determining your location by measuring distance. This method is most often used when moving along a linear landmark or along it (along a road, clearing, etc.), as well as when moving in azimuth. At the starting point, they record the speedometer reading and start moving. When determining your location, you should plot on the map the distance traveled from the starting point to the stopping point. If the movement is made on foot or on skis, the distance traveled is measured in steps or determined by the time of movement.

In the direction of the landmark and the distance to it the standing point can be determined if only one landmark is identified on the ground and on the map. In this case, on an oriented map, a ruler is applied to the symbol of an identified landmark, it is sighted at a landmark on the ground, a straight line is drawn along the edge of the ruler and the distance from the landmark is marked on it. The point obtained on the line of sight will be the desired standing point.

Determining your location along the target. A target is a straight line passing through the standing point and two other characteristic points of the terrain (landmarks).

Determining the standing point by alignment and linear landmark Determination of the standing point by alignment and lateral landmark Determining the standing point by a notch using a lateral landmark Determining the standing point by a notching using three landmarks (back notching)

If the observer is on the target line, its location on the map can be determined in one of the following ways: - by target and linear landmark. For example, if we are on a linear landmark (road) and in alignment with two local objects, it is enough to draw a straight line on the map through the symbols of local objects (landmarks), in alignment with which the point on the ground is located, until it intersects with the road. The point of intersection of the target line with the road will be the desired standing point; - along the target and lateral landmark. For example, the direction of the street in a populated area is the target. To determine the standing point, orient the map along the target line, and then, applying a ruler to a side landmark (a separate tree), sight it and draw a straight line until it intersects with the target line. At the intersection of the target line with the line of sight to the landmark there will be a standing point; - by measured distance. To do this, draw a target line on the map. Then determine the distance to the nearest landmark located on the target line, and plot this distance on a drawn straight line (from the landmark towards you). The point obtained on the straight line will be the standing point. By notching, the standing point is determined under the condition of a good overview of the area and the presence of local objects and landforms on it that can serve as reliable landmarks. According to a lateral landmark, a notch is made, as a rule, when moving along a road or along some linear landmark. For example, while on the road, they orient the map, identify on it the image of an object (landmark) that is clearly visible on the ground, apply the sight line to the symbol of the landmark and sight it. Then, without changing the position of the ruler, draw a straight line on the map until it intersects with the conventional road sign. The intersection of the drawn line with the conventional road sign will be the desired standing point. In this way, they most accurately determine their location on the map if the direction to a lateral landmark intersects with the direction of movement at a right angle.

This case is called perpendicular notching.

Taking two or three landmarks is most often done when your location is not marked on the map.

The map is oriented using a compass and two or three landmarks shown on the map are identified on the ground. Then, as in the previous case, they sight one by one at the selected landmarks and draw directions from the landmarks towards themselves along the ruler. All these directions must intersect at one point, which will be the standing point. This type of serif is often called a back serif.

Construct the measured angles on transparent paper with a randomly drawn point taken as the standing point; these angles can also be constructed by direct sighting using a ruler at selected landmarks on the ground;

The standing point can be determined on the map in various ways: by the nearest landmarks by eye, by measuring the distance traveled, by notching. The method for determining the standing point is selected taking into account the available time, environmental conditions and the required accuracy.

Finding your location according to the nearest landmarks by eye. This is the most common method. On an oriented map, one or two local objects visible on the ground are identified, then they visually determine their location relative to these objects in the directions and distances to them and mark the point of their standing (Fig. 66).

If the standing point on the ground is located next to any local object or its characteristic bend (turn) shown on the map, then the location of the symbol (turning point) of this object will coincide with the desired standing point.

Measuring the distance. This method is most often used when moving along a linear landmark or along it (along a road, clearing, etc.), as well as when moving in azimuth. At the starting point, they record the speedometer reading and start moving. When determining your location, you should plot on the map the distance traveled from the starting point to the stopping point. If the movement is made on foot or on skis, the distance traveled is measured in steps or determined by the time of movement.

In the direction of the landmark and the distance to it the standing point can be determined if only one landmark is identified on the ground and on the map. In this case, on an oriented map, a ruler is applied to the symbol of an identified landmark, it is sighted at a landmark on the ground, a straight line is drawn along the edge of the ruler and the distance from the landmark is marked on it. The point obtained on the line of sight will be the desired standing point.

On target. A target is a straight line passing through the standing point and two other characteristic points of the terrain (landmarks).

If the vehicle is on the target line, its location on the map can be determined in one of the following ways:

Along the alignment and linear reference (Fig. 67). If we are on a linear landmark (road) and in alignment with two local objects, it is enough to draw a straight line on the map through the symbols of local objects (landmarks), in alignment with which there is a standing point on the ground, until it intersects with the road. The point of intersection of the target line with the road will be the desired standing point;

Along the target and lateral landmark. In the figure shown. In the 68 example, the target is the direction of the street of the settlement. To determine the standing point, orient the map along the target line, and then, applying a ruler to a side landmark (a separate tree), sight it and draw a straight line until it intersects with the target line. At the intersection of the target line with the line of sight to the landmark there will be a standing point;

By measured distance. A target line is drawn on the map. Then determine the distance to the nearest landmark located on the target line, and plot this distance on a drawn straight line (from the landmark towards you). The point obtained on the straight line will be the standing point.

Serif The standing point is determined subject to a good overview of the area and the presence of local objects and landforms on it that can serve as reliable landmarks.

According to the lateral landmark (Fig. 69), a notch is made, as a rule, when moving along the road or along some linear landmark. While on the road, they orientate the map, identify on it the image of an object (landmark) that is clearly visible on the ground, apply the sight line to the symbol of the landmark and sight it. Then, without changing the position of the ruler, draw a straight line on the map until it intersects with the conventional road sign. The intersection of the drawn line with the conventional road sign will be the desired standing point.

In this way, they most accurately determine their location on the map if the direction to a lateral landmark intersects with the direction of movement at a right angle. This case is called perpendicular notching.

Using two or three landmarks (Fig. 70), a survey is most often carried out when your location is not indicated on the map. The map is oriented using a compass and two or three landmarks shown on the map are identified on the ground. Then, as in the previous case, they sight one by one at the selected landmarks and draw directions from the landmarks towards themselves along the ruler. All these directions must intersect at one point, which will be the standing point. This type of serif is often called a back serif.

Notching using measured (constructed) angles (Fig. 71) (Bolotov’s method) is performed in the following sequence:

Using a tower inclinometer or another method, such as a compass, measure the horizontal angles between three landmarks selected around the standing point and clearly depicted on the map;

Construct the measured angles on transparent paper with a randomly drawn point taken as the standing point; these angles can also be constructed by direct sighting using a ruler at selected landmarks on the ground;

Place the paper on the map so that each direction drawn on it passes through the symbol of the landmark to which it was drawn when sighting or plotted according to the measured angles;

Having combined all the directions with the corresponding symbols of landmarks, they pin the point marked on a sheet of paper at which the directions were drawn onto the map. This point will be the standing point.

At reverse directional angles (Fig. 72), notching is most often performed in situations where it is impossible to openly work with the map on the ground. In this case, return azimuths are measured with a compass from the standing point to two or three point landmarks visible on the ground and identified on the map. The values ​​of back azimuths are counted on the compass scale against the pointer located at the rear sight. The measured azimuths are converted to directional angles (see Section 5.3). Then, having constructed these angles with the corresponding landmarks on the map, they draw the directions until they intersect with each other. The point of intersection of the directions will be the standing point.

When determining the standing point using any method of notching, you should choose directions so that they intersect at an angle of no less than 30 and no more than 150°. In all possible cases, check the position of the resulting standing point by sighting on an additional local object (landmark). If a triangle is formed at the intersection of three directions, the standing point is placed in its center. If the triangle is large, when its side is more than 2 mm, the notch must be repeated, having first checked the accuracy of the map orientation.