Every point on the earth's surface has a longitude and latitude. If you find these values, you can determine the geographic coordinates of the object. Once you find yourself in unfamiliar terrain and have lost your bearings in the form of a high hill or a prominent tree, calculate the latitude and longitude to find them on the map. And the map and compass will help you find your way back.
It is necessary
- - clock;
- - protractor.
You must first determine the geographic longitude. This value shows the deviation of the object from the prime meridian, from 0 ° to 180 °. If the desired point is east of Greenwich, the value is called east longitude, if west - west longitude. One degree is equal to 1/360 of the equator.
Pay attention to the fact that in one hour the Earth turns 15 ° longitude, and in four minutes it goes 1 °. Your watch should show the correct local time. To find out the geographic longitude, you need to set the local noon time.
Find a straight stick 1-1.5 meters long. Stick it vertically into the ground. As soon as the shadow from the stick falls from south to north, and the sundial “shows” 12 o'clock, time the time. This is the local noon. Translate the received data to Greenwich Mean Time.
Subtract 12. From the result obtained, convert this difference to a degree measure. This method does not give 100% of the result, and the longitude from your calculations may differ from the true geographic longitude of your location by 0 ° - 4 °.
Remember, if the local noon came before noon GMT, this is east longitude, if later it is west. Now you must set the geographic latitude. This value shows the deviation of an object from the equator to the north (north latitude) or south (south latitude) side, from 0 ° to 90 °.
Please note that the average length of one degree of latitude is approximately 111.12 km. To determine the geographical latitude, you need to wait for the night. Prepare the protractor and point the bottom of it (base) at the polar star.
Place the protractor upside down, but so that the zero degree is opposite the polar star. Look, opposite to what degree the hole in the middle of the protractor is located. This will be the geographic latitude.