How to measure azimuth using a compass. How to determine azimuth using a protractor from a topographic map? Drawing a detected object on a map

How to determine azimuth?

Azimuth is an indicator that is used in geography, geodesy, cartography and other sciences. It indicates the angle at a certain point on the ground between the direction to the north and any object (or object on the map). You can find even more information about this indicator in our article -.

How to determine azimuth: methods

You can determine the azimuth using both a compass (if there is no map of the area) and using a regular protractor (if the angle is measured for an object on the map). The azimuth angle can be from 0 to 360 degrees. The countdown is made in a clockwise direction, with the reference point (0°) being the northernmost point on the map (terrain).

In this case, it is easiest to determine the azimuth of both northern and southern, eastern and western objects: it is always 0°, 180°, 90° and 270°, respectively. It should be noted that there is no 360° azimuth, since its value coincides with the 0° azimuth, so it is customary to consider the north direction as an angle with a value of 0°. You can read more about determining the cardinal directions in our article -.

Determining azimuth using a protractor

In addition to the protractor itself, a ruler, pencil and map are also useful for this. To measure an angle, you need to place a ruler so that the point (object, object), the azimuth of which is determined, intersects with the nearest meridian. You can draw a light line with a pencil. The angle measured between this line and the meridian (direction north) will be the desired azimuth.

Determine azimuth using a compass

How to determine azimuth using a compass if you don’t have a map at hand or if you don’t have a protractor with a graduated scale indicating degrees? In this way, the true azimuth is usually measured, which may differ from the magnetic one. For example, if the azimuth of an object is determined to be 40 degrees, then it may not be worth moving taking this change into account.

This is where a map comes in handy: on it you need to find the magnetic correction closest to the desired object. She may be different meanings(for example “+2” or “-3”). When determining an azimuth of 40 degrees, the magnetic correction must be taken into account and moved in the direction with the value of this correction taken into account.

At school they told me how to determine azimuth using a compass. I remember this, but never in my life have I been able to put it into practice. I even have a compass at home, everything is waiting in the wings.

Determination of azimuth by compass

Why do you need to look for azimuth? To quickly find your way around. To do this you will need a map and compass. In ancient times, people were able to determine it by the stars, the Sun and improvised objects. Now everything has changed, although these methods can still help in our time.

Let's say I'm now in a mountainous area. I have a compass in one hand and a local map in the other. Here's what I do next.

1. I determine my location and the correct course I will take. To begin with, I will choose a reference point for myself. This could be a large tree or other object. I take a compass and a map.
2. The compass has a special mechanism that keeps the needle on the brake. It is magnetized and always points north. First, I make sure that there is nothing nearby made or constructed of metal. There is a possibility that the arrow will point in the wrong direction. Now you can release the arrow from the brake.
3. I place the device on the map so that the compass needle coincides with the mark on the map that points north.
4. Now I determine the azimuth. The azimuth will be the angle between the north arrow and the landmark.
5. This is how I determine the azimuth, which will help me find the right path on the ground.

DIY compass

Not everyone has a compass at hand. Therefore, you can do it yourself. Of course, a professional device will show more accurate results, and it is also equipped with additional features, but it is not always possible to use this.

How to make a compass at home.

1. Take a small piece of polystyrene foam or any material that does not sink in water and a needle.
2. Hold one side of the needle near the magnet for a few minutes.
3. Demagnetize the other side using fire.
4. Pierce the foam with a needle.
5. Pour water into a non-metallic container and place an improvised magnetic needle in it.

Hi all! Continuing the topic of terrain orientation, as promised, I propose an article about azimuth and how to determine it. On any hike or journey, when using a map, if poor visibility or the terrain does not allow you to visually compare the map and the terrain, determining the azimuth and moving along it will greatly facilitate the task of orientation. So, what is azimuth?

Azimuth is the angle between the direction of the geographic meridian and the direction to any distant object from the observation point (denoted as Am). Azimuth is measured in degrees and can range from 0° to 360°, usually measured clockwise. Azimuths can be forward and backward. Direct azimuth, measured from 0° clockwise, shows the direction from the observer to the object. Reverse azimuth shows the direction from the object to the observer. To obtain a reverse azimuth, you need to add 180° to the forward azimuth if the forward azimuth is less than 180°, or subtract this value if it is more than 180°. Example: direct azimuth to a lonely tree is 330°, then the reverse azimuth will be: 330°-180°=150°. For quick definition landmarks, you need to remember the directions of the main and intermediate sides of the horizon in degrees, clockwise: North - 0° (or 360°, if counterclockwise), East - 90°, Northeast - 45°, Southeast - 135°, South - 180°, South-West - 225°, West - 270°, North-West - 315°.

When determining the cardinal directions (horizon), it is necessary to take into account that the geographical and magnetic poles of the earth do not coincide; they are located at some distance from each other. Therefore, the compass needle does not point exactly to the North, but slightly to the side, to the North magnetic pole. The same thing happens with South Pole, in the southern hemisphere of the earth. To avoid confusion in calculations, you need to know that any map is oriented to the geographic pole, and the compass needle points to the magnetic pole. The difference between them is several degrees, this angle is called Magnetic declination. Magnetic declination may be Eastern; the compass needle deviates east of the true (geographical) meridian and is designated “+”. Or Western, the arrow deflects to the west and the designation “-”. This difference must be taken into account when transferring the azimuth obtained on the map (true azimuth) to the azimuth along which you will walk using a compass (magnetic azimuth). When converting true azimuth to magnetic, with an eastern declination, the true azimuth must be reduced by the amount of declination, and with a western declination, increased. The magnitude of magnetic declination is not the same in different terrain, for example: for the Moscow region it is +7, +8° (eastern declination), but in general on the territory of Russia it varies within significant limits. There is a site where you can determine the magnetic declination for any point on earth.

To determine the azimuth on the ground using a compass, stand facing a landmark, the direction to which must be determined by rotating the compass, aligning the northern end of the compass needle with the zero division on the dial (compass dial). Next, leaving the compass body motionless and making sure that the needle does not move away from the zero division, we rotate the sighting device until the rear sight is aimed at the object whose azimuth needs to be determined. We mark near which number on the dial the triangle pointer stopped, combine the object, front sight and rear sight into one line, the resulting angle between the compass needle and the orientation object will be the desired azimuth.

Next, we will consider methods of moving on the map, using a pre-planned route, along azimuths. The number of landmarks and the choice of route are determined depending on the nature of the terrain, tasks and conditions of the upcoming movement. The main thing is to choose a route that would provide quick access to the designated landmark (object). Therefore, it is advisable to choose a route without unnecessary turns, with sections that are most convenient for movement, taking into account avoidance of obstacles encountered on the ground. And so, we select landmarks and connect them with straight lines (example in the figure); if they do not intersect the grid lines on the map, they need to be continued until they intersect, this is done to facilitate the determination of azimuth angles. After this, on the map, for each section of the route, we determine the directional angle and, by introducing a direction correction, we convert it to magnetic azimuth, which we write down on the map opposite the corresponding section. We measure this angle clockwise, using a protractor or compass. This is done this way: we lay the map with the route drawn on a flat surface, orient it as accurately as possible according to the compass, taking into account the direction correction. Then, without changing the orientation of the map, we apply a compass to the first line of the route, so that the North - South direction coincides with the drawn direction, while North should be directed in the direction of movement. After the compass needle has calmed down, we take a reading along the compass dial, under its northern end, subtract the resulting number from 360° and obtain the magnetic azimuth of the desired direction. For example (in the figure), in the first section the magnetic azimuth is: 360°-340°=20°, the azimuth of the second section: 360°-30°=330°, in the same way, sequentially, we determine the azimuths of all other sections of the route. Next, we measure the length of each section; on the ground this can be done using the method of a couple of steps ( average length 2 pairs of steps = 1.5 meters), example: if the distance of the site is 1200 m, then in pairs of steps it will be: 1200: 1.5 = 800 pairs of steps. It is also advisable to record the time of passage of each section on the clock. All data is also recorded on the map, against its plots.

When moving along azimuths, on the ground, you may encounter all sorts of obstacles (forest debris, swamps, lakes, etc.) that are easier to bypass than to overcome. Therefore, you need to be able to avoid obstacles without losing your orientation. Let's consider two ways to avoid obstacles: 1 when the opposite side of the obstacle is visible (Fig. a), 2 when the opposite side of the obstacle is not visible (Fig. b). In the first case, everything is simple: we notice a landmark in the direction of movement, on the opposite side of the obstacle, and without losing sight of it, we go around the obstacle, continuing to move along the planned route, from the landmark that we used when going around (Fig. a). The second case is more complicated, we proceed as follows, example: (Fig. b) let’s assume that the movement was made in an azimuth of 50° and 340 pairs of steps were taken before stopping in front of the obstacle. After studying the area, it was decided to go around the obstacle on the left side. Using a compass, we determine the azimuth of the direction along the obstacle (from point A to point B), and continue moving in this direction, while counting a couple of steps to the right edge of the obstacle. In the figure, the azimuth from point A to point B is 320°, and the distance traveled is 142 pairs of steps. We stop at point B, determine by compass the direction of the original azimuth along which you were moving until you meet an obstacle 50°, continue moving until you go beyond the obstacle and count in pairs of steps, from point B to leaving the obstacle to point C, in the figure , the distance is 238 pairs of steps. From point C we move to the right, we already have data on the azimuth of movement from point A to point B, we translate them into reverse azimuth (in the figure the reverse azimuth is 140°) and move from point C, along the reverse azimuth, counting exactly 142 pairs of steps , this will be point D, at point D, we again determine using the compass, the azimuth direction of the initial movement is 50° and continue moving along the intended route. Be sure to save data on avoiding obstacles and add distances to the route, this will help calculate the distance traveled when moving back along the same azimuths.

If the situation allows, it is best to avoid obstacles using linear landmarks, these can be clearings, rivers, streams, power lines; their azimuths are determined and marked on the map in advance, this will significantly facilitate the orientation of your movement on the move. At the slightest doubt about the correctness of movement, in both of the above cases, it is necessary to stop and clarify your location by carefully comparing the map with the terrain; an example of correct comparison of the map with the terrain is shown in the figure above.

To accurately orient the map, you can use a regular pencil by placing it on conventional sign landmark on the map (example in the figure, a bridge), combine its direction with the direction of the landmark on the ground. Then check whether all local objects and landforms located on the ground to the right and left of the bridge have the same location on the map. If all conditions match, the map is oriented correctly. And lastly, the main reasons for orientation errors are not faulty equipment, but the lack of skills and experience in using this equipment. Constant training and improving your knowledge in this area will help you find your way to the place you need in a critical situation. To start orienteering training, you don’t even have to leave the house, just determine the point of your location in the room and from it determine the azimuths of the objects in this room.

Instructions

Find a landmark in the direction in which you should move. Straight-line movement Possibly in airspace and on the high seas. On land, this is applicable in the open steppe or in.

Most often, movement on land is carried out along a broken line, taking into account obstacles. Therefore, you will need to periodically adjust the azimuth while moving.

Therefore, find on the map the note closest to the area of ​​your location with the magnetic value. It is expressed in degrees and can be either with a + or a minus sign.

Enter the correction and move confidently, guided by the compass.

note

Azimuth (denoted “Az” or “Az”) - in geodesy, the angle between the direction to the north (in the Southern Hemisphere - to the south) and the direction to some distant object. It is usually counted clockwise.

Helpful advice

Azimuth is the angle formed between the direction towards any terrain object and the direction to the north. To determine a given azimuth on the ground, you must: set the pointer of the compass sighting device with a point above the division corresponding to the value of the given azimuth; turn the compass so that the sight pointer is in front

The terrain is often oriented not only by the cardinal points, but also by the direction of certain objects, which are well tracked visually and can be effectively used for orientation.

You will need

• - compass

Instructions

Azimuth- this is an angle measured clockwise from one of the cardinal points or another pre-selected direction. To determine a magnetic object, use a compass. Place the compass on a horizontal, flat surface and turn it so that the arrow points to zero on the scale. Then the sighting scale is rotated until the orientation becomes visible through the rear sight and front sight. Then the front sight will show the azimuth of the object on the scale.

For determining azimuth and take the compass in your hands, release the brake of the magnetic needle. Place the compass in a strictly horizontal position. After the arrow stops oscillating and calms down, align the zero scale mark with the end of the arrow that points north. You have just completed the compass orientation.

Now, carefully, so as not to disorient the compass, turn its cover so that the front sight is directed towards the selected landmark, and the slot is towards you. To do this, you need to look through the slot and the front sight at the landmark. Make sure that the end of the arrow is always aligned with the division. The count located opposite the pointer (near the front sight) will be a numerical expression azimuth but for this reference point.

If you are faced with the inverse problem, that is, finding the desired direction according to a known azimuth y, then set the pointer at the front sight equal to the specified azimuth y countdown (for example, 300 degrees). Now set the compass horizontally and point north in the manner described above. Carefully, trying not to lose your orientation, look through the slot and the front sight. Select a landmark on this line. The direction from your standing point to the landmark will correspond to this azimuth u.

Magnetic azimuths measured from the direction of the magnetic meridian, which is indicated by the direction of the magnetic compass needle. A conditional azimuth is called when a conditional meridian is taken to calculate it.

Instructions

If you know the declination angle for a certain point at a certain epoch, you can determine with a certain accuracy the true magnetic azimuth and, conversely, the true magnetic azimuth. All meridians converge at the same point - . The angle between two is the name of the angle of approach of the meridians. If you intersect several meridians with a straight line, at the points of their intersection azimuths, differing from each other by this very angle of convergence of the meridians. Its magnitude of two points of one straight line will depend on its length, direction, as well as the latitude of the place. The azimuth, which is measured at the starting point of the line, is called direct. The reverse azimuth (a2) is equal to the forward azimuth (a1) plus or minus 180 degrees, as well as plus the angle of approach of the meridians (t). It turns out: a2=a1±180°+t.

For a line of 15 km in mid-latitudes, the angle of convergence of the meridians is approximately 10’ in everyday practice; as a rule, such a small angle is neglected, considering that the direct and reverse azimuths differ from each other by 180o (a2=a1±180o). This is accepted at a lower level in cases with small surfaces.

For large distances, as well as high-precision measurements, calculations are made according to all the rules of higher geodesy, taking into account the angle of approach of the meridians and the spherical kurtosis, expressed in centimeters. The formula in such cases is as follows: a2=a1±180°+t-e, ​​where t is the approach angle, which is calculated using special formulas, e is the spherical kurtosis, which is also calculated using a special formula.

Video on the topic

Everyone knows that you can navigate the terrain using a compass. But in order to do this practically, you need to know the rules of measurement. azimuth. To do this, determine the angle between the direction to the north and the given direction to the object of interest to the observer.

You will need

• Compass, small steel object, match or ruler

Instructions

Check your compass. Take a steel object (regular keys, a small knife, scissors, etc. work well). Place the compass on a horizontal surface; if the needle has a fastening, release it. The arrow will be oriented in a certain direction. Take the object, and, placing it opposite the northern end of the arrow, start it along the compass body in any direction. The arrow should focus on the object and move, pointing at it. After completing a quarter turn, remove the metal object. The arrow should again orient itself to the position from which it started moving.

Before starting measurements, make sure that there are no bodies made of steel, cast iron or current-carrying conductors in the immediate vicinity of the compass. Determine the value of the compass scale division. To do this, take the two closest numerical values ​​on it and subtract the smaller from the larger one. Divide the result by the number of divisions between these numbers.

Place the compass on a horizontal surface and release its needle, if a mount is provided. Wait for the arrow to balance and point north (like , that's the blue end of the arrow, the red one points south). Set the compass scale correctly. To do this, turn it until the corresponding 0º coincides with the northern end of the arrow. Orient yourself in the right direction.

To do this as accurately as possible, place a straight and thin object in a given direction, it can be an even twig, a match, a ruler, etc. In this case, the object should under no circumstances be made of any iron, otherwise the arrow will immediately go astray. With on calculate the angle between the compass needle and the direction on required item. This angle will be the azimuth. Knowing the azimuth from a certain point, you can easily navigate the area without fear of getting lost.

Sources:

• how to measure azimuth

You can clearly navigate any terrain using a compass. But to learn how to determine directions, you need to know how to calculate azimuth. To do this, measure the angle between the direction of the object you want to move towards and the north direction.

You will need

• - compass;
• - a small steel object;
• - ruler or straight splinter.

Instructions

First check the compass. To do this, take a steel object (it could be keys, scissors, etc.). Place the compass on a horizontal plane and remove the arrow mount, if present. The arrow should point to . Take the prepared steel object and, placing it opposite the end of the arrow pointing north, move it along the body of the device. The arrow should point to the steel object. After making a quarter turn (on a conventional clock dial this will be 15 minutes), remove the object. The arrow should return to its original position, that is, point to the north.

Before calculation azimuth and be sure to check if there are any objects around the compass made of, current-carrying conductors or permanent magnets, this may negatively affect the measurements. After this, decide on the value of the compass scale division, which measures the degree by which the needle rotates. Take the two closest digital values ​​and divide their difference by the number of divisions between them.

Set the compass horizontally and remove the stop from the arrow. After a few hesitations, the end of the arrow should point north. Set the compass scale so that its pointer coincides with the direction of the arrow. This point corresponds to zero azimuth u.

After this, you can navigate the area. Place a thin and oblong object in the direction of the object being oriented. It could be a twig, a splinter, a match, etc. The only limitation is that the object should not be or be made from any alloy of this, otherwise the arrow will simply start pointing at this object, making it difficult azimuth A.

Calculate the angle between the direction towards the object and the direction north. To do this, count the number of divisions between them and multiply this number by the price of the scale division.

Determining the azimuth helps in orientation on the ground, allows you to maintain direction and not go astray while traveling through the plains, taiga and other places where there are no landmarks. Suitable for driving in the dark, in bad weather conditions, when visibility is very low.

How to find azimuth with a map in theory

You can determine the azimuth using a topographic map (the true meridian is calculated) or a compass (the magnetic meridian is found). When combined, these meridians form an angle called magnetic declination. To find the true azimuth, you must first calculate the magnetic one using a compass and add the eastern magnetic declination to the resulting value, or subtract the western declination. It is determined using a reference book, read on the map if it is indicated.

Calculating azimuth from a map helps determine direction not only for travelers on the ground. This method is used to calculate the route for aircraft and ships. Establish a movement trajectory for ground transport in the steppes, deserts, savannas, where there are no direction signs and other landmarks.

It is not difficult to determine the azimuth on the map; it is the angle between the meridian and the direction to the place of arrival. On the map, trying to be as accurate as possible, mark the point of your location. This will be the starting coordinate for constructing the route.

Determining the azimuth allows you to create the route most suitable for the characteristics of each area. If there are no natural or artificial obstacles on the intended route, then the movement is straightforward. If obstacles appear, the route is adjusted as necessary, and the movement follows a broken trajectory.

Creating a route using azimuth and map

To create a route in azimuth and determine the trajectory of movement, you must have:

• large-scale topographic map;
• ruler;
• pencil;
• protractor, it is preferable to choose a transparent one.

To determine the azimuth on the map, the points of the present location and the final destination are indicated. A ruler is applied to the map. Draw a connecting line between the points with a pencil, crossing the meridians closest to the points. The base of the protractor is applied to the meridian, its arc should be directed towards the landmark (end point). The central mark must be aligned with the drawn line. You can determine the azimuth at the intersection of the drawn line and the arc of the protractor by taking readings in degrees.

When determining the route, take into account the obstacles encountered that need to be avoided (deep ravines, swamps, lakes, various buildings). Turning points along the entire length of the route are marked on the map and connected. Points are placed near natural and artificial landmarks in order to better control the consistency of the route. For each segment it is necessary to find the azimuth using the method described above. If the transition is carried out at night, then reference points are placed on the map more often.

How to determine magnetic azimuth

Magnetic azimuth is the angle between the final (defined) point of the route and the direction to the north. Determination of azimuth by compass done like this:

1. Stand strictly in the direction of the point of movement (object).
2. The compass is placed on a flat surface no higher than chest level, or held in front of you on an outstretched palm.
3. The compass is oriented by aligning the dark end of the magnetic needle with the letter C.
4. A thin stick (match) is placed on the center of the compass. Its end is directed towards the designated point. The stick is turned clockwise, preventing it from moving from the center.
5. Under the stick, on the dial, they look at the digital value.

You can determine the azimuth within the entire circle; its value sometimes reaches 360 degrees. An azimuth with such an angle is considered zero.

Additionally you can find azimuth using a map and compass:

1. The compass is placed on the side edge of the map.
2. The card is turned until the top edge coincides with “C”, and the side edge of the card coincides with the direction of the dark end of the magnetic needle.
3. Two points are marked on the map - the starting point and the ending point, and connect them with a line.
4. The compass is moved until its center aligns with the starting point.
5. The drawn line will coincide with the digital value of the compass.

This method allows you to find the direct magnetic azimuth. For better orientation on the terrain and drawing up a route for return, a reverse azimuth calculation is made. To do this, 180 degrees are subtracted or added from the resulting straight line if the found angle is greater or less than the unfolded angle, respectively.

In a similar way, azimuth is determined using a compass without a map, but in this case you need to imagine conventional points and images in your mind, looking at the surroundings from a higher point.

Azimuth movement with obstacles

When the azimuth route has impassable obstacles , then you should adhere to the following rules:

1. On the opposite side of the obstacle, choose the most memorable landmark that runs in the direction of movement.
2. Determine the azimuth for the detour.
3. If on back side there is no suitable landmark, it is necessary to mark it on the spot. To do this, make a notch on the tree trunk and stick a large stick into the ground.
4. Go around the obstacle, find the intended landmark. From there, continue moving in azimuth, having previously checked the direction.

In case of zero visibility, the obstacle is avoided using a compass, if a route has not been drawn up on the map before. In front of a difficult area, it is necessary to determine the azimuth to bypass it. Mentally mark the point from which they will start moving. It is important to maintain linearity when moving along and count the number of pairs of steps.

Having reached the end of the obstacle, you need to turn and determine the azimuth using the compass. They continue to move further, count pairs of steps, and maintain linearity. Having completely gone around the obstacle, they return to the original trajectory of movement - calculate the return azimuth, observe the number of pairs of steps from the beginning of the detour to the turning point. After returning to the route, they continue in the direction planned to the obstacle.

How to find azimuth according to the sun

There are situations when it is necessary to navigate the terrain and there are no available means other than a wristwatch. In this case, you need to know how determine the azimuth of the sun using the dial:

1. Place the watch on a flat surface with the hour hand pointing towards the sun.
2. A line is drawn from the center of the dial through “1”, and the resulting angle is divided in half.
3. The drawn bisector indicates the north-south direction. Before noon, north is to the left of the sun, after noon to the right. Therefore, before 12 o'clock the azimuth calculation is done by counting the values ​​counterclockwise, after 12 o'clock they count clockwise.
4. The route is drawn up by analogy with a compass.

This allows you to determine the direction of movement with small errors. The azimuth of the sun is measured in degrees from the south to the point on the horizon where the luminary is located at different periods of time - before noon in the east, after noon in the west.