Military maps are maps measured for military purposes. Including topographic maps, military nautical maps, aviation maps, aerospace maps and other military special maps (such as military geography maps, coastal areas maps, military water network distribution maps, water quality and water source maps, etc.).
Military maps are one of the important tools in modern warfare. It is used for the study of strategy and campaigns, the organization and command of various military services to coordinate operations, the planning, design and construction of various national defense projects, various military training and exercises, various tactical operations (such as studying the terrain of the enemy and our war zone, selecting positions, observation sites, hidden areas and close areas. The design and construction of fortifications, determining the arrangement of weapons, and implementing maritime and air combat, etc.). In outdoor directional sports , you must learn the basic knowledge of military maps. If you do not understand military map knowledge, you cannot participate in outdoor directional sports competitions. has many puppet military fans who talk about military knowledge, but they don’t even understand the basic military map knowledge. If a general who commands thousands of troops cannot even understand the military map, how can he command on the battlefield? Are you waiting to lose? Whether you are a military enthusiast or a wild activity enthusiast, you need to learn some basic military map knowledge. In this section, we will mainly talk about the relevant knowledge of military maps.
Before studying this chapter, I suggest you review the previous three basics:
Due to different latitudes, the lengths of the south and north maps on the map are also different. The meridian of the measured point is the position of the point you are looking for. On a large-scale topographic map, when finding the position on a certain point based on geographical coordinates, you can first use the latitude as the latitude, and then use the longitude as the longitude as the longitude, then the intersection of the two lines is the position on the figure of the point you are looking for. If there are many points you are looking for, you can first connect them to a geographical coordinate network according to the index band, and then determine the position of each point on the graph according to the latitude and longitude values of each point.
2. Plane rectangular coordinate
determines the length value of a certain point position on the plane, which is called the plane rectangular coordinate of the point.
(1) The composition of plane straight angle coordinate network. The plane rectangular coordinate network on my country's topographic map is drawn as a projection belt according to the Gaussian projector longitude of 6°. The central meridian line of each projection belt is the vertical axis (X axis), the equator is the horizontal axis (Y axis), and its intersection is the coordinate origin (0). In this way, each projection belt forms an independent coordinate system. As shown in Figure 7-3.
To facilitate measuring the coordinates of any point from each map, in units of kilometers, and using several straight lines parallel to the vertical and horizontal axis at equal distances, forming a plane rectangular coordinate network, also known as Fangli Network. As shown in Figure 7 - 4
(2) Application of plane rectangular coordinates. Plane Cartesian coordinates are mainly used to indicate and determine the position of the target on the figure, and can also estimate distance and area based on the grid. When indicating and determining the target, proceed in the order of vertical coordinate first and horizontal coordinates.
① Use general coordinates to indicate the target and determine the position on the graph of the target. When using rough coordinates to indicate the target and determine the position of the target on the graph, only use the kilometer value of the square where the target is located. First, use rough coordinates to indicate the target. As shown in Figure 7-5, when indicating the position of the 116.6 high ground, you can first find that the vertical coordinate of the horizontal line below the point is 67, and then find that the horizontal coordinate of the left vertical line is 46, and the general coordinate of the point is 67 and 46.
If you need to clearly indicate the position of the target in the grid or have more than C of the same target in a grid, you can divide one grid into nine small grids (tic toe grids), and number them according to the method in Figure 7-5. When indicating the target, add the number of the small grid after the general coordinates. As shown in Figure 7-5, the coordinates of the wooden bridge are 66 and 47. The last two digits of the kilometers are added to indicate the target. It is only applicable to a range of 100 kilometers. If it exceeds 100 kilometers, the rail will be repeated, causing confusion. To avoid the above phenomenon, all values of the picture name, number or coordinates used should be pointed out at this time. As shown in Figure 7-5, the U 6.6 highland coordinates are vertical 3267 and horizontal 18646". Second, use the general coordinates to determine the position of the target on the graph. When determining the position of the daily mark on the graph based on the coordinates, you can first find the vertical coordinate according to the coordinate numbers, and then find the horizontal coordinate. In the upper right grid of the intersection of the two coordinates, you can find the target.
② Use precise coordinates to indicate the target and determine the position of the target on the graph. The exact coordinate consists of the general coordinate (kilometer) of the target plus the value distance (meter) of the point to the lower part of the grid and the left coordinate line, which is used to accurately indicate and determine the position on the graph of a certain point.
First, use precise coordinates to indicate the target. Use coordinates to measure coordinates, and the method is simple and fast. As shown in Figures 7-6, when measuring the exact coordinates of the firepower launch point, the following methods can be adopted.
A, find out the general coordinates of the emission point are 85 and 49, and make the vertical edge of the coordinate ruler (or right-angle edge of the triangle plate) coincide with the longitudinal line of 49, and the horizontal edge is tangent to the emission point. When reading, the number of meters is estimated and then added to the number of kilometers.
B, first estimate the number of divisions for the 85 horizontal line from the vertical edge of the coordinate ruler to be 645m, and then add it to 85km, and the vertical coordinate is 85 645m.
C, estimate the division number of the emission point cut from the horizontal edge of the coordinate ruler is 300m, add it to 49km, and the horizontal coordinate is 49 300m. The exact coordinates of the emission point of
are: vertical 85645 and horizontal 49300, and the total coordinate values are: vertical 2785645 and horizontal 18249300.
Second, use precise coordinates to determine the position on the target graph.
If the exact coordinates of the enemy observation site are known to be: vertical 86075 and horizontal 48410, the method is as follows when determining the position on the figure.
A, as shown in Figure 7-6, first find the square where the target is based on the general coordinate 86.48.
B, make the vertical edge of the coordinate ruler coincide with the 48 coordinate vertical line, and make the 075m division cut on the 86 coordinate horizontal line.
C, find the 410-meter division along the horizontal edge of the coordinate ruler, which is the position on the figure of this point. When using plane rectangular coordinates to indicate targets, in the telephone report, the coordinates should be reported first, and then the location and target should be reported, such as "Coordinates: 85, 49 (85645, 49300), Guishan enemy fire launch point". In written documents, the location should be written first, and then the coordinates and targets should be determined, such as "Guishan (85645, 49300). Enemy Fire Launch Point".
In order to maintain military secrets, high-level command agencies usually use the coordinates of the topographic map into codes during wartime. The easiest way is to add or subtract a constant from the original coordinate number on the topographic map. If the number of kilometers of the original vertical coordinate is 21, 22, 23........ Add
"20" to each, which means it becomes 41. 42, 4..... If you subtract one "10" each, it will be: it becomes 11, 12, 13...
2. The map segmentation is the same as the number
. In order to match the size of the map, the topographic maps of various scales have segmentation and number. The segments and numbers of various scale terrain in my country are based on the segments and numbers of the international one percent topographic map and are divided according to certain latitude and eternal differences. This makes it easy to measure, use and store. If the picture number is based on the picture number, the location of the picture, including the range and the map scale can be quickly found. The image number is located directly above the northern profile.
my country's new topographic map segments and numbers are as follows;
1. 1:1 million topographic map
0 The actual area range included in each topographic map is 4° latitude difference and 6” longitude difference. From the equator of the earth, each latitude difference is 4° to the poles is a column, and is represented by the numbers 1, 2,...222 in turn; from 180° longitude, each 6 in length from west to east is a row, and is represented by the numbers 1. 2, 3...., and its numbers are composed in the order of "horizontal row number-vertical row number". As shown in Figure 7-8, the number of the 1:1 million topographic map where Beijing is located is 10.-50.
2. 1:500,000 topographic map
The actual field range included in each topographic map is latitude difference of 2* and elongation difference of 3". That is, each 1:1 million topographic map is divided into 4 1:500,000 topographic maps, represented by A, B, C and D respectively. As shown in Figure 7-9, the number of the 1:500,000 topographic map where Beijing is located is 10-50-A.
3. 1:200,000 topographic map
Each topographic map includes a latitude difference of 40’ and a longitude difference of 1”. That is, it is divided into 36 1:200,000 topographic maps in units of 1:1 million topographic maps, which are represented by bracketed numbers (1), (2), (3) ...... (36). As shown in Figure 7-9, the number of the 1:200,000 topographic map where Beijing is located is 10-50- (3).
4. 1:100,000 topographic map The actual field range included in each topographic map is 20' and 30'. That is, each 1:100,000 topographic map is divided into 144 1:100,000 topographic maps, represented by numbers 1.2,...444 respectively.As shown in Figure 7-10, the number of the 1:100,000 topographic map where Beijing is located is 10-50-5.
5.1:50,000 topographic map
This topographic map includes a latitude difference of 10 and a longitude difference of 15'. That is, each 1:100,000 topographic map is divided into 4 1:50,000 topographic maps, represented by A, B, C and D respectively. As shown in Figure 7-11, the number of the 1:50,000 topographic map where Beijing is located is 10-50
-5-B. It is divided into 4 1:25,000 topographic maps in units of each 1:50,000 topographic map, represented by the numbers 1, 2.3, and 4, as shown in Figure 7-11, the number of the 1:25,000 topographic map where Beijing is located is 10-50-5-B-4.
3. Map collage and fold
To facilitate the use of maps, multiple maps are often collaged. For ease of storage and carrying, the map is often folded reasonably.
1. Map collage
(1) connected to the chart. A chart is a chart used to represent the relationship position of each picture in a certain area. It is used to facilitate the search of maps and thus facilitate map collage.
large-scale chart: a chart that represents the relationship position of each map in the country or a larger area. It is painted with warp nets, and each grid represents a picture with the number of the picture. The table also includes major cities, rivers and roads.
② Small connection chart: There are 9 small grids printed in the upper left corner of each map. Each - - small grid represents the - picture, with a diagonal line drawn in the middle to represent the picture. The remaining 8 grids are adjacent pictures, and the corresponding picture names are noted in the grid. On the 1:500,000 and 1:1 million images, each grid also has a corresponding picture number, as shown in Table 7-1. On large-scale maps and 1:200,000 maps, in addition to noting the figure names of adjacent maps in the small-connected chart, adjacent map numbers are also noting them in each map contour,
is shown in Figure 7-12.
When there is no chart connected, you can draw it yourself or use a 1:1 million terrain map to draw. The drawing method is to draw an appropriate large rectangle or draw a certain grid and indicate the latitude and longitude of the grid line and the graph size according to the terrain map on a 1:1 million map.
(2) Collage method.
①Arrange each map according to its related position according to the name and number of adjacent maps noted by the chart.
② Generally, according to the habit of "pressing up and down" and "pressing left and right", cut the southern and eastern edges along the contour line of the inner picture. The rightmost row does not cut the eastern edges, and the lowest
column does not cut the southern edges to keep the map full edges after the collage. For certain information on the edge of the cut figure, such as declining angle diagram, you can clip it in the appropriate position of the figure when needed. When collage adjacent maps, if you need to use a unified coordinate network, you should be collaged in the appropriate position before the edge of the clipping map. When collage
, the main land objects can be connected to each other. If there are few vertical lines, then the vertical lines will be pasted from top to bottom; if there are few horizontal lines, then the horizontal lines will be pasted from right to left. After the rows (columns) are cloned, then put them together.
2. Collapse of map
(1) Collapse of multiple maps. For easy portability and use, the map after the collage is often folded and the coordinates of the used part are noted. The method is: fold the unnecessary part to the back and fold it into an accordion style according to the size of the capsule, as shown in Figure 7-13. .
(2) Collapse of a single map. In order to facilitate picking, splicing and carrying, a single map also needs to be folded. There are usually two styles, and the folding method is described as follows. The first type: When folding, first fold the image up and down to reveal the image name; then fold the map up and down to three equally, fold backwards, first fold the right side, then fold the left side to reveal the image name.
The second type: When folding, first fold back along the east inner contour and the north inner contour; then make the picture face opposite, fold up and down in half, then divide the map with half folds up and down in three equal parts, and align the drawings to reveal the name of the picture. As shown in Figure 7-15.
4. azimuth angle and declination angle
1. Azimuth angle
starts from the north direction line of a certain point, and is horizontally included between the clockwise direction and the target direction line, which is called the azimuth angle from the point to the target. It is represented by a dense position or degree. As shown in Figure 7-16. The azimuth angle from the stand point to the pavilion is 10-00 (pronounced as a thousand secret positions), and the azimuth angle from the memorial tower is 42-00 (pronounced as 42, 000).
is oriented on the map according to the needs of the local map, and three different starting direction lines are used, namely the true meridian, the magnetic meridian, and the coordinate vertical line. Therefore, from a certain point to the same goal, there are three azimuth angles with different meanings. As shown in Figure 7-17.
(1) True meridian and True azimuth angle. The true meridian passes through any point of meridian. Because the meridian line passes through the North and South Pole of the Earth, the direction it points to is the true north and south direction, so a certain point towards the North Pole is called the True North.
Starting from the true meridian of a certain point, it depends on the horizontal angle between the clockwise direction to the target direction line, which is called the true azimuth angle from the point to the target (A). Usually used in precision measurements.
(2) Magnetic meridian and magnetic azimuth angle. The magnetic meridian is the north-south direction line pointed by any magnetic needle on the ground. The magnetic needle north is called magnetic north. The magnetic meridian passes through the north and south magnetic poles of the earth. The north and south magnetic poles are not at - -. According to 1975 measurements, the north magnetic poles are located at 76°12’ north latitude, 100*36’ west longitude, and 139*24’ east longitude. The magnetic south and magnetic north (or P, P') are drawn on the map's south and north maps. The connecting lines of these two points are the magnetic meridians of the figure. Starting from the magnetic north direction line of a certain point, the horizontal angle between the clockwise direction to the target direction line is called the magnetic azimuth angle (Am) from the point to the target. It is widely used when aviation, navigation, artillery shooting, and army travel.
(3) The coordinate vertical line and the coordinate azimuth angle of . After the map is marked, the vertical line on the map is the northern end of the coordinate vertical line, which roughly points to the north, so it is called the coordinate north. Starting from the north of the coordinate vertical line of a certain point, the horizontal angle between the coordinate vertical line clockwise and the target direction line is called the coordinate azimuth angle from the point to the target (a). Artillery is used more frequently, and it is not only easy to measure from the figure, but also can be converted into a magnetic azimuth angle.
2. Decline
0 Due to the inconsistent direction of the real meridian, magnetic meridian, and coordinate vertical line (abbreviated as the three north direction line), the horizontal angle formed is called the decline or the three north direction angle. There are three types of decline angles.
( 1) magnetic deflection angle . The horizontal angle between the magnetic meridian and the true meridian is called the magnetic deflection angle, as shown in Figure 7-18. The magnetic deflection angle is based on the true meridian. The magnetic meridian is east of the true meridian and deflection eastward, and the angle value is positive; the magnetic meridian is west of the true meridian and deflection angle is negative. The magnetic deflection angle is measured on the ground, and the deflection angle varies from place to place. The magnetic deflection angle noted on the map is the average value of the magnetic deflection within the amplitude range of the figure.
(2) The deflection angle of the coordinate vertical line. The angle between the coordinate vertical line and the true meridian is called the coordinate vertical line deflection angle (y), also known as the meridian convergence angle, as shown in Figure 7- 18. Taking the true meridian as the basis, the coordinate vertical line is eastward to the east of the true meridian, and the angle value is positive; the coordinate vertical line is westward to the west of the true meridian, and the angle value is negative. The graphs east of the central meridian, and the graphs westward are all eastward. The closer to the central meridian and the equator, the smaller the deflection value; conversely, the larger the deflection value, but the maximum does not exceed 3".
(3) Magnetic coordinate deflection angle. The angle between the magnetic meridian and the coordinate vertical line is called the magnetic coordinate deflection angle. As shown in Figure 7-18. The coordinate vertical line is the basis. The magnetic meridian is east of the coordinate vertical line, and the angle value is positive; the magnetic meridian is west of the coordinate vertical line, and the angle value is negative. It is sometimes the sum of the coordinates of the longitudinal deflection values of the magnetic deflection angle, and sometimes the difference between the two. The deflection angle diagram composed of the above three deflection angles (i.e., the three north direction map) is drawn below the southern map contour of the map. There are ten kinds of deflection angle diagrams. As shown in Figure 7-19.
3. Conversion of azimuth angle
coordinate azimuth angle and magnetic azimuth angle
(1) Basic formula:
Example 7-2
As shown in Figure 7-21, it is known that the coordinate azimuth angle from the gun position to the protruding tree is 51-00, and the magnetic coordinate deflection angle is westward 0-83. Find the magnetic azimuth angle from the gun position to the protruding tree?
Solution: According to the formula for finding the magnetic azimuth angle, Am=51-00-(-0-83)=51-83. In calculation, when the addition of the two angle values is greater than 60-00, 60-00 should be subtracted. If the small angle value is reduced to the large angle value, the small angle should be added to 60-00 and then subtracted from the large angle value.
4. Measure the coordinate azimuth angle on the graph and graphically illustrate the coordinate azimuth angle
(1) Measure the coordinate azimuth angle on the graph.
① Use protractor to measure it. As shown in Figure 7-22, the coordinate azimuth angles of △171.4 to .162.6 are read as follows.
first, connect △171.4 to .162.6 straight lines. If two points are in the same square, the connection line should be extended to intersect with the coordinate vertical line.
Second, align the center of the protractor at the intersection of the connecting line and the coordinate line (the azimuth value is less than 30-00, the protractor is placed on the right side of the coordinate vertical line, the angle value is greater than 30-00, and placed on the left side of the coordinate vertical line), dig northward with zero division, and make the zero-dense bit line coincide with the coordinate vertical line. Third, read out the dividing number 17-40 of the two-point connection line through the edge of the protractor, that is, the coordinate azimuth angle of △171.4 to 162.6. If the coordinate azimuth angle is greater than 30-00, the protractor should be placed on the left side of the coordinate vertical line, so that the zero division faces south, and then add the read dense digits 30-00, which is the azimuth angle for the measurement reading.
② Use the artillery command ruler to measure and read. The artillery command ruler is shown in Figure 7-23. The left and arc edges of the command ruler are engraved with dense position divisions and notes in the reverse clockwise direction, which is called the dense position angle ruler edge, abbreviated as the angle ruler edge. The zero point of distance division is the center of the circle divided by angle division, and the coordinate azimuth angle of △197.0 to 0187.5 is measured. The method is as follows.
First, pass the midpoint of 0197.0, and make a line parallel to the coordinate vertical line (when the target is 15-00 to 30-00 or 45-00 to 60-00, make a line parallel to the coordinate horizontal line).
second, aligned with the center of the command ruler to △197.0, so that the distance ruler edge is tangent to the target day 187.5 (the distance ruler edge is always the end edge of the azimuth).
Third, read out the parallel line (red straight line) through the command ruler angle ruler 6-60, that is, the coordinate azimuth angle of △197.0 to 0187.5.
If the target is at the position of 15-00 to 30-00, the read division number should be added 15-00; when the position of 30-00 to 45-00, 30-00 should be added; when the position of 45-00 to 60-00, 45-00 should be added, that is, the coordinate azimuth angle to be measured.
(2) illustrates the coordinate azimuth angle on the figure. For example, the azimuth angle of the reference direction coordinate is 7-00. To mark the reference direction of the gun position on the figure, you can follow the following key steps, as shown in Figure 7-24.
① Make a parallel line of coordinate vertical lines through the gun position (when the angle of the diagram is greater than 15-00, the method of making parallel lines is the same as measuring the coordinate azimuth angle.
②At the right side of the ruler, the center of the circle is aligned with the gun position, and turn the command ruler to make the dense position of the angle value (in this example, 7-00) be aligned with the parallel lines. Then, draw a straight line PJ along the distance ruler, that is, the reference line of the gun position. When the coordinate azimuth angle of the diagram is between 15-00 and 30-00, 15-00 should be subtracted and then illustrated; when between 30-00 and 45-00, 30-00 should be subtracted; when between 45-00 and 60-00, 45- 00.
This section is about the knowledge about military maps. In the next issue, we will introduce you to how to use military maps to march in the field.
② Use precise coordinates to indicate the target and determine the position of the target on the graph. The exact coordinate consists of the general coordinate (kilometer) of the target plus the value distance (meter) of the point to the lower part of the grid and the left coordinate line, which is used to accurately indicate and determine the position on the graph of a certain point.
First, use precise coordinates to indicate the target. Use coordinates to measure coordinates, and the method is simple and fast. As shown in Figures 7-6, when measuring the exact coordinates of the firepower launch point, the following methods can be adopted.
A, find out the general coordinates of the emission point are 85 and 49, and make the vertical edge of the coordinate ruler (or right-angle edge of the triangle plate) coincide with the longitudinal line of 49, and the horizontal edge is tangent to the emission point. When reading, the number of meters is estimated and then added to the number of kilometers.
B, first estimate the number of divisions for the 85 horizontal line from the vertical edge of the coordinate ruler to be 645m, and then add it to 85km, and the vertical coordinate is 85 645m.
C, estimate the division number of the emission point cut from the horizontal edge of the coordinate ruler is 300m, add it to 49km, and the horizontal coordinate is 49 300m. The exact coordinates of the emission point of
are: vertical 85645 and horizontal 49300, and the total coordinate values are: vertical 2785645 and horizontal 18249300.
Second, use precise coordinates to determine the position on the target graph.
If the exact coordinates of the enemy observation site are known to be: vertical 86075 and horizontal 48410, the method is as follows when determining the position on the figure.
A, as shown in Figure 7-6, first find the square where the target is based on the general coordinate 86.48.
B, make the vertical edge of the coordinate ruler coincide with the 48 coordinate vertical line, and make the 075m division cut on the 86 coordinate horizontal line.
C, find the 410-meter division along the horizontal edge of the coordinate ruler, which is the position on the figure of this point. When using plane rectangular coordinates to indicate targets, in the telephone report, the coordinates should be reported first, and then the location and target should be reported, such as "Coordinates: 85, 49 (85645, 49300), Guishan enemy fire launch point". In written documents, the location should be written first, and then the coordinates and targets should be determined, such as "Guishan (85645, 49300). Enemy Fire Launch Point".
In order to maintain military secrets, high-level command agencies usually use the coordinates of the topographic map into codes during wartime. The easiest way is to add or subtract a constant from the original coordinate number on the topographic map. If the number of kilometers of the original vertical coordinate is 21, 22, 23........ Add
"20" to each, which means it becomes 41. 42, 4..... If you subtract one "10" each, it will be: it becomes 11, 12, 13...
2. The map segmentation is the same as the number
. In order to match the size of the map, the topographic maps of various scales have segmentation and number. The segments and numbers of various scale terrain in my country are based on the segments and numbers of the international one percent topographic map and are divided according to certain latitude and eternal differences. This makes it easy to measure, use and store. If the picture number is based on the picture number, the location of the picture, including the range and the map scale can be quickly found. The image number is located directly above the northern profile.
my country's new topographic map segments and numbers are as follows;
1. 1:1 million topographic map
0 The actual area range included in each topographic map is 4° latitude difference and 6” longitude difference. From the equator of the earth, each latitude difference is 4° to the poles is a column, and is represented by the numbers 1, 2,...222 in turn; from 180° longitude, each 6 in length from west to east is a row, and is represented by the numbers 1. 2, 3...., and its numbers are composed in the order of "horizontal row number-vertical row number". As shown in Figure 7-8, the number of the 1:1 million topographic map where Beijing is located is 10.-50.
2. 1:500,000 topographic map
The actual field range included in each topographic map is latitude difference of 2* and elongation difference of 3". That is, each 1:1 million topographic map is divided into 4 1:500,000 topographic maps, represented by A, B, C and D respectively. As shown in Figure 7-9, the number of the 1:500,000 topographic map where Beijing is located is 10-50-A.
3. 1:200,000 topographic map
Each topographic map includes a latitude difference of 40’ and a longitude difference of 1”. That is, it is divided into 36 1:200,000 topographic maps in units of 1:1 million topographic maps, which are represented by bracketed numbers (1), (2), (3) ...... (36). As shown in Figure 7-9, the number of the 1:200,000 topographic map where Beijing is located is 10-50- (3).
4. 1:100,000 topographic map The actual field range included in each topographic map is 20' and 30'. That is, each 1:100,000 topographic map is divided into 144 1:100,000 topographic maps, represented by numbers 1.2,...444 respectively.As shown in Figure 7-10, the number of the 1:100,000 topographic map where Beijing is located is 10-50-5.
5.1:50,000 topographic map
This topographic map includes a latitude difference of 10 and a longitude difference of 15'. That is, each 1:100,000 topographic map is divided into 4 1:50,000 topographic maps, represented by A, B, C and D respectively. As shown in Figure 7-11, the number of the 1:50,000 topographic map where Beijing is located is 10-50
-5-B. It is divided into 4 1:25,000 topographic maps in units of each 1:50,000 topographic map, represented by the numbers 1, 2.3, and 4, as shown in Figure 7-11, the number of the 1:25,000 topographic map where Beijing is located is 10-50-5-B-4.
3. Map collage and fold
To facilitate the use of maps, multiple maps are often collaged. For ease of storage and carrying, the map is often folded reasonably.
1. Map collage
(1) connected to the chart. A chart is a chart used to represent the relationship position of each picture in a certain area. It is used to facilitate the search of maps and thus facilitate map collage.
large-scale chart: a chart that represents the relationship position of each map in the country or a larger area. It is painted with warp nets, and each grid represents a picture with the number of the picture. The table also includes major cities, rivers and roads.
② Small connection chart: There are 9 small grids printed in the upper left corner of each map. Each - - small grid represents the - picture, with a diagonal line drawn in the middle to represent the picture. The remaining 8 grids are adjacent pictures, and the corresponding picture names are noted in the grid. On the 1:500,000 and 1:1 million images, each grid also has a corresponding picture number, as shown in Table 7-1. On large-scale maps and 1:200,000 maps, in addition to noting the figure names of adjacent maps in the small-connected chart, adjacent map numbers are also noting them in each map contour,
is shown in Figure 7-12.
When there is no chart connected, you can draw it yourself or use a 1:1 million terrain map to draw. The drawing method is to draw an appropriate large rectangle or draw a certain grid and indicate the latitude and longitude of the grid line and the graph size according to the terrain map on a 1:1 million map.
(2) Collage method.
①Arrange each map according to its related position according to the name and number of adjacent maps noted by the chart.
② Generally, according to the habit of "pressing up and down" and "pressing left and right", cut the southern and eastern edges along the contour line of the inner picture. The rightmost row does not cut the eastern edges, and the lowest
column does not cut the southern edges to keep the map full edges after the collage. For certain information on the edge of the cut figure, such as declining angle diagram, you can clip it in the appropriate position of the figure when needed. When collage adjacent maps, if you need to use a unified coordinate network, you should be collaged in the appropriate position before the edge of the clipping map. When collage
, the main land objects can be connected to each other. If there are few vertical lines, then the vertical lines will be pasted from top to bottom; if there are few horizontal lines, then the horizontal lines will be pasted from right to left. After the rows (columns) are cloned, then put them together.
2. Collapse of map
(1) Collapse of multiple maps. For easy portability and use, the map after the collage is often folded and the coordinates of the used part are noted. The method is: fold the unnecessary part to the back and fold it into an accordion style according to the size of the capsule, as shown in Figure 7-13. .
(2) Collapse of a single map. In order to facilitate picking, splicing and carrying, a single map also needs to be folded. There are usually two styles, and the folding method is described as follows. The first type: When folding, first fold the image up and down to reveal the image name; then fold the map up and down to three equally, fold backwards, first fold the right side, then fold the left side to reveal the image name.
The second type: When folding, first fold back along the east inner contour and the north inner contour; then make the picture face opposite, fold up and down in half, then divide the map with half folds up and down in three equal parts, and align the drawings to reveal the name of the picture. As shown in Figure 7-15.
4. azimuth angle and declination angle
1. Azimuth angle
starts from the north direction line of a certain point, and is horizontally included between the clockwise direction and the target direction line, which is called the azimuth angle from the point to the target. It is represented by a dense position or degree. As shown in Figure 7-16. The azimuth angle from the stand point to the pavilion is 10-00 (pronounced as a thousand secret positions), and the azimuth angle from the memorial tower is 42-00 (pronounced as 42, 000).
is oriented on the map according to the needs of the local map, and three different starting direction lines are used, namely the true meridian, the magnetic meridian, and the coordinate vertical line. Therefore, from a certain point to the same goal, there are three azimuth angles with different meanings. As shown in Figure 7-17.
(1) True meridian and True azimuth angle. The true meridian passes through any point of meridian. Because the meridian line passes through the North and South Pole of the Earth, the direction it points to is the true north and south direction, so a certain point towards the North Pole is called the True North.
Starting from the true meridian of a certain point, it depends on the horizontal angle between the clockwise direction to the target direction line, which is called the true azimuth angle from the point to the target (A). Usually used in precision measurements.
(2) Magnetic meridian and magnetic azimuth angle. The magnetic meridian is the north-south direction line pointed by any magnetic needle on the ground. The magnetic needle north is called magnetic north. The magnetic meridian passes through the north and south magnetic poles of the earth. The north and south magnetic poles are not at - -. According to 1975 measurements, the north magnetic poles are located at 76°12’ north latitude, 100*36’ west longitude, and 139*24’ east longitude. The magnetic south and magnetic north (or P, P') are drawn on the map's south and north maps. The connecting lines of these two points are the magnetic meridians of the figure. Starting from the magnetic north direction line of a certain point, the horizontal angle between the clockwise direction to the target direction line is called the magnetic azimuth angle (Am) from the point to the target. It is widely used when aviation, navigation, artillery shooting, and army travel.
(3) The coordinate vertical line and the coordinate azimuth angle of . After the map is marked, the vertical line on the map is the northern end of the coordinate vertical line, which roughly points to the north, so it is called the coordinate north. Starting from the north of the coordinate vertical line of a certain point, the horizontal angle between the coordinate vertical line clockwise and the target direction line is called the coordinate azimuth angle from the point to the target (a). Artillery is used more frequently, and it is not only easy to measure from the figure, but also can be converted into a magnetic azimuth angle.
2. Decline
0 Due to the inconsistent direction of the real meridian, magnetic meridian, and coordinate vertical line (abbreviated as the three north direction line), the horizontal angle formed is called the decline or the three north direction angle. There are three types of decline angles.
( 1) magnetic deflection angle . The horizontal angle between the magnetic meridian and the true meridian is called the magnetic deflection angle, as shown in Figure 7-18. The magnetic deflection angle is based on the true meridian. The magnetic meridian is east of the true meridian and deflection eastward, and the angle value is positive; the magnetic meridian is west of the true meridian and deflection angle is negative. The magnetic deflection angle is measured on the ground, and the deflection angle varies from place to place. The magnetic deflection angle noted on the map is the average value of the magnetic deflection within the amplitude range of the figure.
(2) The deflection angle of the coordinate vertical line. The angle between the coordinate vertical line and the true meridian is called the coordinate vertical line deflection angle (y), also known as the meridian convergence angle, as shown in Figure 7- 18. Taking the true meridian as the basis, the coordinate vertical line is eastward to the east of the true meridian, and the angle value is positive; the coordinate vertical line is westward to the west of the true meridian, and the angle value is negative. The graphs east of the central meridian, and the graphs westward are all eastward. The closer to the central meridian and the equator, the smaller the deflection value; conversely, the larger the deflection value, but the maximum does not exceed 3".
(3) Magnetic coordinate deflection angle. The angle between the magnetic meridian and the coordinate vertical line is called the magnetic coordinate deflection angle. As shown in Figure 7-18. The coordinate vertical line is the basis. The magnetic meridian is east of the coordinate vertical line, and the angle value is positive; the magnetic meridian is west of the coordinate vertical line, and the angle value is negative. It is sometimes the sum of the coordinates of the longitudinal deflection values of the magnetic deflection angle, and sometimes the difference between the two. The deflection angle diagram composed of the above three deflection angles (i.e., the three north direction map) is drawn below the southern map contour of the map. There are ten kinds of deflection angle diagrams. As shown in Figure 7-19.
3. Conversion of azimuth angle
coordinate azimuth angle and magnetic azimuth angle
(1) Basic formula:
Example 7-2
As shown in Figure 7-21, it is known that the coordinate azimuth angle from the gun position to the protruding tree is 51-00, and the magnetic coordinate deflection angle is westward 0-83. Find the magnetic azimuth angle from the gun position to the protruding tree?
Solution: According to the formula for finding the magnetic azimuth angle, Am=51-00-(-0-83)=51-83. In calculation, when the addition of the two angle values is greater than 60-00, 60-00 should be subtracted. If the small angle value is reduced to the large angle value, the small angle should be added to 60-00 and then subtracted from the large angle value.
4. Measure the coordinate azimuth angle on the graph and graphically illustrate the coordinate azimuth angle
(1) Measure the coordinate azimuth angle on the graph.
① Use protractor to measure it. As shown in Figure 7-22, the coordinate azimuth angles of △171.4 to .162.6 are read as follows.
first, connect △171.4 to .162.6 straight lines. If two points are in the same square, the connection line should be extended to intersect with the coordinate vertical line.
Second, align the center of the protractor at the intersection of the connecting line and the coordinate line (the azimuth value is less than 30-00, the protractor is placed on the right side of the coordinate vertical line, the angle value is greater than 30-00, and placed on the left side of the coordinate vertical line), dig northward with zero division, and make the zero-dense bit line coincide with the coordinate vertical line. Third, read out the dividing number 17-40 of the two-point connection line through the edge of the protractor, that is, the coordinate azimuth angle of △171.4 to 162.6. If the coordinate azimuth angle is greater than 30-00, the protractor should be placed on the left side of the coordinate vertical line, so that the zero division faces south, and then add the read dense digits 30-00, which is the azimuth angle for the measurement reading.
② Use the artillery command ruler to measure and read. The artillery command ruler is shown in Figure 7-23. The left and arc edges of the command ruler are engraved with dense position divisions and notes in the reverse clockwise direction, which is called the dense position angle ruler edge, abbreviated as the angle ruler edge. The zero point of distance division is the center of the circle divided by angle division, and the coordinate azimuth angle of △197.0 to 0187.5 is measured. The method is as follows.
First, pass the midpoint of 0197.0, and make a line parallel to the coordinate vertical line (when the target is 15-00 to 30-00 or 45-00 to 60-00, make a line parallel to the coordinate horizontal line).
second, aligned with the center of the command ruler to △197.0, so that the distance ruler edge is tangent to the target day 187.5 (the distance ruler edge is always the end edge of the azimuth).
Third, read out the parallel line (red straight line) through the command ruler angle ruler 6-60, that is, the coordinate azimuth angle of △197.0 to 0187.5.
If the target is at the position of 15-00 to 30-00, the read division number should be added 15-00; when the position of 30-00 to 45-00, 30-00 should be added; when the position of 45-00 to 60-00, 45-00 should be added, that is, the coordinate azimuth angle to be measured.
(2) illustrates the coordinate azimuth angle on the figure. For example, the azimuth angle of the reference direction coordinate is 7-00. To mark the reference direction of the gun position on the figure, you can follow the following key steps, as shown in Figure 7-24.
① Make a parallel line of coordinate vertical lines through the gun position (when the angle of the diagram is greater than 15-00, the method of making parallel lines is the same as measuring the coordinate azimuth angle.
②At the right side of the ruler, the center of the circle is aligned with the gun position, and turn the command ruler to make the dense position of the angle value (in this example, 7-00) be aligned with the parallel lines. Then, draw a straight line PJ along the distance ruler, that is, the reference line of the gun position. When the coordinate azimuth angle of the diagram is between 15-00 and 30-00, 15-00 should be subtracted and then illustrated; when between 30-00 and 45-00, 30-00 should be subtracted; when between 45-00 and 60-00, 45- 00.
This section is about the knowledge about military maps. In the next issue, we will introduce you to how to use military maps to march in the field.
