Did you know that most compasses don't actually point to the North Pole? That's right! In reality most compasses point to magnetic north, which is a point in the Arctic Ocean that is near (but not equal to) the North Pole. Generally these minor differences are often overlooked in everyday life, but if you take them seriously for navigating directions in the wilderness, you will run into problems. Fortunately, there are various ways to find true north (the direction that points to the North Pole) using anything from modern computers to just the sun, moon, and stars.
Step
Method 1 of 2: Adjusting the Compass to Declination
Step 1. Find your local declination from the NGDC website
One of the reasons navigators have difficulty distinguishing between true north and magnetic north is that the effect on the compass can change over time. This phenomenon is called declination. As the Earth's magnetic field changes, the angle of deviation of the compass also shifts from true north. Therefore, to accurately adjust the compass to account for this effect, it requires the current declination value for your location.
Fortunately, the NGDC website (National Geophysical Data Center, whose duties are similar to the Indonesian Meteorology, Climatology and Geophysics Agency) continues to record the latest global declination values. On the NGDC website, you can enter your current location to get the latest available declination values for the area
Step 2. Find the declination value through the map as an alternative way
There are maps that also include declination values for the area shown. Topographic maps are more likely to include this kind of information, although you may find it on other types of maps. If you are considering navigating using a map and compass, check the symbols on the map to see if it has accurate declination data.
Of course, you should keep in mind that declination changes over time, so older maps are no longer accurate. For the most accurate value, use the most recent published map
Step 3. Find magnetic north using a compass
Once you know the magnitude of the deviation of your compass from true north, it is not difficult to adjust for this difference. Start by finding the direction of magnetic north. Hold the compass horizontally in front of your chest. If your compass has a travel arrow (an arrow that points to the direction you want to go, usually a pointer at the base of the compass), point it forward. Pay attention to the movement of the compass needle. When the compass needle stops moving, look at the direction the compass needle is pointing. This direction is the north-south axis.
Most modern compasses have a needle that is half red and half white. In this kind of compass, the red tip of the compass needle points north
Step 4. Rotate the orientation arrow so that it points in front of you
If you are navigating using a compass, this is usually when you will adjust the compass bezel (the outer frame of the compass that has degrees and can be rotated, if your compass has this feature) in the direction you want to go, i.e. towards the front, parallel to the travel. arrows. In this case, since we are aiming to find true north, we will rotate the outer frame of the compass so that the letter "N" (and the pointer below it) is pointing in front of us.
Note that this direction is magnetic north, not true north, so we still have to adjust to the declination
Step 5. Adjust to the declination
Rotate your body until the compass needle is aligned with the orientation arrow on the outer frame of the compass (and thus the travel arrow). You are now facing magnetic north. To find true north, rotate the compass outer frame according to the magnitude and direction of your location's declination value. Most compasses have degree markings on the outer frame of the compass to help you do this. Next, align the compass needle and orientation arrow by turning your body again. You should now be facing true north!
For example, suppose that initially we get the declination value of 14o East for the area we are in. If we are facing magnetic north, we just have to rotate the outer frame of the compass by 14.o towards the east (in this case, turn it clockwise). Then, we'll switch to facing left (i.e. west) to align the compass needle with the orientation arrow so that we're facing true north (14o west of magnetic north).
Method 2 of 2: Finding True North Without Using a Compass
For the Northern Hemisphere
Step 1. Use the movement of the sun
If you don't have a compass, don't worry. You may still find true north by using clues from nature. For example, because the sun rises in the east and sets in the west, we can use this information to get a rough estimate of the direction of north. Just after sunrise, you face north when the sun is on your right, and just before sunset, the sun is on your left. At noon, the sun will be in the south. So, face the opposite side of the sun to know which direction is north.
One way to more accurately determine the direction "north" is to use a stick as a kind of timepiece by using the sun's shadow. Stick a stick in the ground and mark the tip of the shadow. Wait about fifteen minutes, then again mark the location of the new shadow on the ground. Stand with your left foot at the first mark and your right foot at the second mark. The direction you are facing is more or less true north, regardless of the declination of the area you are in
Step 2. Use an analog watch
One practical trick to finding true north is to use an analog watch. Remove the watch and hold it with the short hand facing forward. Rotate your body so that the short hand is pointing toward the sun. Look for the midpoint between the short hand and the 12 o'clock marker at the top. This point will point to the north-south axis.
- For example, suppose it's 4 p.m. The midpoint between 16.00 and 12.00 is 14.00 so if we point the short hand towards the sun, the north-south axis will be no more than a quarter turn to our left. Given that it is evening and the sun is setting in the west, we can conclude that the north direction will be behind us as it faces the 14.00 o'clock marker (number 2).
- Don't forget to take Daylight Saving Time into account if you're in a country that uses that time system! If your watch is adjusted to take DST time into account, use the 13:00 hour marker (number 1) instead of the 12:00 hour marker.
Step 3. Look for natural signs
Certain natural organisms (especially plants and trees) can provide clues about the direction of north. However, these rules are obviously very "loose" and don't always match. So, for most of the cases, other ways are preferred. Here are some examples of what can be observed:
- Moss: May be thicker on the south side of the tree due to more sun exposure.
- Trees: The color of the bark may fade and the branches stretch higher on the north side due to less sun exposure.
- Ants: The mounds of anthills tend to be on the south side of the warmer part of nature.
- Snow: Snow melts faster on the south side of trees and rocks because it receives more sunlight.
Step 4. Use Polaris, also known as the North Star
North is very easy to find at night if you know what to look for. Polaris is almost perfectly aligned with Earth's North Pole. So if you can find it, you'll know exactly where north really is. There are several ways to find Polaris, but the easiest is usually the Big Dipper. The two stars at the "scoop" end of the constellation point directly at Polaris.
Unfortunately, Polaris cannot be seen from the southern hemisphere so it is only useful for navigation north of the equator
Step 5. Use the moon
Just like the sun, the moon moves across the sky in an east to west direction. This means that you can use the moon's position to help determine true north at night. At the beginning of the night, you face north if the moon is on the right side, whereas when the night is late, the moon is on the left side. When the moon is at its highest point in the sky, that point is roughly south so you'd find north if you were facing the other way around.
If the moon is a crescent at that time, you can also draw an imaginary line through the two ends of the crescent towards the horizon to find south, then face the other way to find north. This method is best done when the moon is high in the sky
For the Southern Hemisphere
Step 1. Use the sun's movement
Given that sunlight, moon, and stars hit the southern hemisphere at different angles than the northern hemisphere, the process of searching for north is slightly different for the south of the equator. For example, although the sun still rises in the east and sets in the west for the southern hemisphere, during the day the sun is in the north, not in the south.
Thus, even though your facing direction will still make the sun on the right side just after sunrise and on the left side just before sunset to face north, you will still face the sun to find the direction north at noon
Step 2. Use an analog watch
Since the sun passes on the north side (rather than the south side) in the Southern Hemisphere, the way to find north using a wristwatch is essentially reversed. Point the 12:00 o'clock marker on the watch toward the sun, then look for the line that marks the midpoint between the 12:00 o'clock marker and the short hand. This line will represent the north-south axis.
For example, if it is 18.00, we will find the north-south axis passing through the 15.00 and 21.00 hour markers on the watch. Because it is evening, we know that the sun is in the western sky. Thus, when we point the 12 o'clock marker at the sun, the 3 o'clock marker (number 3) will show an approximate true north direction
Step 3. Use the Southern Cross star at night
The Southern Hemisphere does not have a polar star like Polaris which makes navigation easier. The most similar constellation is a constellation called the Southern Cross that rotates around the south celestial pole. To estimate the direction south, look for the star of the Southern Cross and draw a direct line that descends to the horizon. This line more or less indicates the direction south. So turn around to find the north direction.
The easiest way to find the Southern Cross star is to use the Pointer star, which is the two brightest stars in the southern sky that point directly at the Southern Cross star. Pointer stars can be found in the white, irregular clusters of the Milky Way galaxy cluster, which are often seen in locations with little or no light pollution
Step 4. Use the moon
In the southern hemisphere, the moon still passes from east to west, just like the sun. However, at the highest point in the sky, that point is north, not south. This means that the direction of navigation using the crescent moon will be reversed. The line that runs through the pointed end of the crescent to the horizon will point approximately north, not south.
