How To Know A Place Altitude

Sometimes we are faced with a condition where we should be able to determine the altitude of a place, but we do not have the tools to determine the altitude (altimeter), it can be solved by:

-See a map of the first interval, then compute the height where we want to know, there is a general formulation of the contour interval = 1/2000 scale map. tetapim formula is not always true, some output Geological Survey topographic map of the original Bandung scale 1:50,000 (contour interval 25 m), but later enlarged to scale 1:25.000 with a fixed 25-meter contour interval.

At the urging of a particular condition, such as SAR mountain forests, often in the map reproduced by photocopy. Therefore, the contour interval map must still be written. Bakosurtanal output maps (1:50,000) to make a thick contour for each multiple of 250 meters, or each contour interval 10. AMS series output maps (1:50,000 scale) to make a thick contour lines for each multiple of 100 meters. Geological map of the output Bandung thickness is not uniform provisions of the contour lines. Thus there are no special provisions for the determination and uniformly thick contour lines.

When the height contours are not listed, then we have to calculate the altitude of a place by:

A. Find the two points adjacent to the listed price

2. Calculate the difference in height between the two points. Calculate how many contours found between the two (not counting the contours of the same price if the two points separated by a valley).

3. By knowing the difference in height of the two points and knowing also the number of contour is obtained, can be calculated how much the contour interval (must be an integer).

4. See one of the closest contour point height (if it is above the nearest contour point, the price of the contours is greater than the height of the point. When the contour is located at the bottom, costs less). Calculate the price of the nearest kontuir which must be a multiple of the price of a known contour interval of no 3. doing calculations on a few times until confident that the price obtained for each contour correctly. Include the price of some of the contours on your map so you can easily remember.

Triangulation point

Apart from the contour lines, we may be able to find a place with the help of high-altitude titk. The point of elevation is usually the point of triangulation, which is an object of the pillars titikatau / milestone menyatakn a place of absolute height above sea level. Triangulation points used by the service-bureau topography to determine the altitude of the measurement science at the time of making maps. Kind of triangulation points:

- Primary: Quaternary P.14/3120: Q.20/1350

- Secondary: Tertiary S.75/1750: T.16/975

Know the Signs Medan

In addition to the field marks contained on the legend. Topographic maps used to use the forms or striking landscapes in the field and easily recognizable on the map, which we call sign field. Some signs of terrain you can "read" off the map before you go to the site, but then there should be looking for the location, field signs include:

- Top of a mountain or a hill, mountain ridge, the valley between two peaks, and other forms of conspicuous bulge.

- Steep valleys, rivers, creeks meeting, bend in the river, the cliffs on the banks of the river.

- Winding road, bridge (intersection of the river by the way), the end of the village crossroads.

- When at the beach, the estuary of the river would be a very clear sign of the field, as well as the promontory that juts into the sea, striking bays, small islands, deltas, etc.

- In the area of ​​land or marshes are usually difficult to obtain the Earth's surface protrusions or hills that can be worn as a sign of the field. Surface of the bend-bend of the river, the river branches, small estuaries.

- In the traverse on the river, a sharp bend, a branch of the river, cliffs, delta and so can be used as a field mark.

This field marks the absolute sense to master. Will always be used in the subsequent description of the technique map compass.

Compass

A. To Compass

Compass is a compass that is used to determine the direction of magnetic north. Due to the nature kemagnetannya, the compass needle will point north-south direction (if not influenced by the presence of magnetic forces other than the Earth's magnetic). But keep in mind that the direction designated by the compass needle is the earth's magnetic north, so it's not true north.

Physically, the compass consists of: a) the Agency, where the other components of the compass is located; b) The needle always points to north-south position however; c) The scale of the pointer, indicating the degree of the compass system.

2. Types of Reuters, in a way many kinds of compasses that can be used, is generally used two types of compasses, the compass scene (eg prismatic compass) and compass orienteering (eg compass silva). Compass viewfinder is easy to aim, but in reading the map need to be equipped with a protractor and a ruler. Silva compass is less accurate when used for aiming, but a lot of help in reading and computation on the map. Compass is well on its tip coated with phosphor to be visible in the dark.

3. Use of Compass, the compass is used with a horizontal position in accordance with the direction of the Earth's magnetic field lines. In using the compass, it should be kept away from the influence of objects containing metal, such as knives, machetes, karabiner, watches and more. The presence of these objects will affect the compass needle so that its accuracy will be reduced.

Altimeter

altimeter is the altitude measuring device that can assist in determining the position. In the high mountainous terrain, using a compass resection is often not much help, here is more useful altimeter. Along the ridge-ridge with easily recognizable on the map, altimeter will be more involved in the trip, which must be considered in the use of altimeter:

- Used every altimeter must be calibrated. Check the accuracy of the altimeter at an altitude points for sure.

- Altimeter is very sensitive to shocks, changes in weather and temperature change.