Author: Wg Cdr Rajagopal

Parallels of Latitude form one of the components for fixing a position without ambiguity on the surface of earth. Equator forms the basis for defining the parallels of latitude. We are ready to understand about the parallels of latitude since we had learnt about the Equator and Meridians in our previous lesson. SMALL CIRCLES Small Circles are circles on surface of earth whose centre and radius are not the same as that of earth. To be more exact the radius of a Small Circle would be smaller than the circumference…

Parallels of latitude and Meridians of Longitudes are the two components of Position Reference System. In this lesson, we shall learn about the Equator and Meridians . Equator serves as the Datum Reference for measurement of Latitudes. In our earlier post, we had learnt about the properties of Great Circles. EQUATOR Equator is a Great Circle whose plane is perpendicular to the Axis of Rotation of earth. On the other hand Meridians are semi-great circles joining the poles. Just like other Great Circles, the Equator also cuts the earth into…

In order to understand about positions on the surface of earth, we need to first learn about Great Circles. Just as a remider, we had learnt about the Sexagesimal System of Direction Measurement in our earlier lesson. In case you have not seen the post, please go through the lessons on measurement of directions. In order to understand Great Circles, take a globe and put an elastic band exactly in its mid-point. You can see that the rubber band would stay in place only at one particular position which is…