You will need
- - protractor.
First you have to determine geographical longitude. This value shows the deviation of the object from the zero Meridian, from 0° to 180°. If desired point East of Greenwich, the value is called East longitude, if West – West longitude. One degree is 1/360 of a full part of the equator.
Pay attention to the fact that in one hour the Earth turns 15 degrees of longitude, and the four minutes goes by 1°. Your watch should show accurate local time. To know the geographical longitude, you need to set the time of local noon.
Find a straight stick the length of 1-1. 5 meters. Stick it vertically in the ground. As soon as the shadow from the stick will fall from South to North, and the sundial will "show" 12 o'clock, note the time. This is local noon. Translate the received data to Greenwich mean time.
From the result subtract 12. This difference in degree measure. This method is not 100% accurate, and longitude of your calculations may differ from the true geographical longitude of your location at 0°- 4°.
Remember, if local noon occurred before noon GMT – this is the East longitude, if later, the West. Now you need to set the geographic latitude. This value shows the deviation of the object from the equator into Northern (North latitude) or South (South latitude) direction, from 0° to 90°.
Please note that the average length of one degree of latitude is approximately equal 111,12 km To determine the latitude we need to wait for the night. Prepare the protractor and move the bottom part (the base) on the North star.
Place the protractor upside down so that zero degrees was opposite the North star. View, on the contrary what degree is the hole in the middle of the protractor. This will be the latitude.
Advice 2: How to determine longitude and latitude
If you find yourself away from civilization and were in an emergency situation, first of all you need to navigate the terrain. In some cases it is necessary to determine the geographic coordinates of its location, for example, to transmit their rescue service. There are several relatively simple ways to determine longitude and latitude.
You will need
- Clock, wooden stick, two strips (a protractor), plumb
For the determination of longitude use the watch, which must be put in place with known longitude. You then detect that the clock at local noon and translate the time difference into degrees. Consider how this works in practice.
Set your watch for the time corresponding to the time at the zero Meridian (GMT). Define noon in the area. For this you may need the gnomon – an ancient sundial. Prepare a stick with a length of 1-1,5 m and its vertical stick in the ground. As the movement of the sun do on the earth level corresponding to the length of the drop shadow. At the approach of the sun to the Zenith, the shadow will become shorter. The shortest shadow of the stick will be during the time of true noon. The shadow of the stick at this time will be sent exactly from South to North.
Determining local noon, note the clock. Then make the difference the amendment. The fact that the angular speed is not constant and depends on the time of year. So to the result add (or subtract) correction.
Let's consider an example. Suppose today is may 2. The clock is set in Moscow. Summer Moscow summer time is different from the world for 4 hours. At local noon, mounted on the sundial, the clock showed 18:36. Thus, the world the time now is 14:35. Subtract from this time 12 hours and get 02:36. Amendment 2 may is 3 minutes (this time should be added). Translating the result in angular measure, will receive 39 degrees West longitude.The described method allows to determine longitude with an accuracy up to three degrees. Given that in an emergency you will not table of the equation of time for the amendment of the calculations, the result may vary from true.
To determine the latitude you will need a protractor and a plumb line. Homemade protractor fabricated from two rectangular strips, cementing them in the form of a compass.
In the center of the protractor, attach the thread with a load (it will play the role of a plumb). Place the base of the protractor on the North star.
From the corner between the base of the protractor and a plumb subtract 90 degrees. We obtained the angle between the North star and the horizon. Since the North star is a deviation from the axis of the pole by just one degree, the angle between the direction of the star and the horizon will be the required latitude of the locality in which you are.