# ES 1300 Lecture Notes - Lecture 1: Cartesian Coordinate System, Antarctic Circle

## Document Summary

Latitude and longitude- finding your location on a sphere. When you are locating a point on a flat surface you can use cartesian coordinates of x and y. Ona body such as the earth or our moon, we can pinpoint the location of any city or landmark using two values, the latitude and longitude. On the earth there are two additional sets of reference points. The equator divides the earth into the northern and the southern hemisphere. The primes meridian divides the earth into the western and eastern hemisphere. Latitude is defined as the elevation of the location point above (or below) the equator. The measurement is expressed in degrees, minutes, and seconds. The equator is at 0 degrees and the poles are at 90 degrees. If the location point is north of the equator n or + is added to the degrees.