How To Determine The Longitude And Latitude | The Science



The Science

How to determine the longitude and latitude

If you are away from the benefits of civilization and put in an emergency situation, first of all you need to navigate the terrain. In some cases it is necessary to determine the geographical coordinates of its location, for example, to transfer them to the rescue service. There are some relatively simple ways to determine the longitude and latitude.

How to determine the longitude and latitude

You will need:

Clock, wooden stick, two strips (protractor) plummet

Instruction how to determine longitude and latitude

Step 1:

To determine geographic longitude, use the clock, during which you need to put in place with a known longitude. This is followed to detect the clock to the local time at noon and convert the difference in degrees. Consider, as it occurs in practice.

Step 2:

Set your clock time corresponding to the time on the zero meridian (GMT). Determine the afternoon in the area. To do this you may need the gnomon - ancient sundial. Prepare a stick length of 1-1.5 m and a vertical slide it into the ground. As the sun moves make a mark on the ground, corresponding to the length of the drop shadow. When the sun approaches the zenith, the shadow will become shorter. The shortest shadow of the stick will be true at the time of midday. Thus the shadow of the stick this time will be directed precisely to the south to the north.

Step 3:

Identify local noon Note the clock. Then, make a difference in the resulting amendment. The fact that the angular speed is not constant and depends on the time of year. So to the result add (or subtract) the amendment.

Step 4:

Consider an example. For example, today on 2 May. The clock is set in Moscow. Moscow summer daylight saving time is different from the world for 4 hours. The local noon, mounted on the sundial, the clock showed 18:36. Thus, world time at the moment is 14:35. Subtract from that time, 12 hours, and get 2:36. Correction for May 2 is 3 minutes (this time must be added). Translating result in angular measure, we get 39 degrees west dolgoty.Opisanny method allows to determine longitude to within three degrees. Given that in an emergency situation at hand is not the equation of time table for amendment of the calculation, the result may be different from the true.

Step 5:

To determine the latitude you need a protractor and a plumb line. Homemade protractor fabricate two rectangular strips, cementing them as a compass.

Step 6:

In the center of the protractor secure the thread with a load (it will act as a plumb line). Move the base of the protractor on the polar star.

Step 7:

Because of the angle between the base of the protractor and plumb subtract 90 degrees. We got the angle between the polar star and the horizon. Since the polar star is the deviation from the axis of the pole by only one degree, the angle between the direction of the star and the horizon is the required breadth of areas in which you are.