Ellipsoids Datums And Projections

The Earth's shape is closest to an ellipsoid. It is wider in the middle and smaller at the poles. 

The Earth is not a perfect ellipsoid. And hard to measure. Over time due to the changing shape of the Earth and newer more accurate technology we have created and use different Ellipsoid maps. 

   A datum is a reference point. It is used to show positions on maps to it's real position on the Earth. Horizontal Datums measure latitude and longitude. Vertical datum are used to measure depth.  Because the Earth is not a perfect ellipsoid Datums provide a more accurate picture of the area.

    A map projection is a way to show the shape of the Earth on a flat surface. Map projections have distortions such as size, shape, angle, and distance. It is important to pick the right map to show what you need.

   The biggest problem I had when using Google Earth had to do with my own error in numbers.

Introduction To Google Earth

     Welcome.  For our first lab, we use Google Earth to help us understand and use GIS technology. This was my first time using Google Earth. I was very impressed with the simplicity of user control. Anyone with basic computer skills will be able to use this app. The user friendliness, makes this a good app for students and travelers. I found most of the tools very easy to use.

    As I worked through the lessons, I kept thinking what a useful tool for travelers. I really liked that as I zoomed in on an area places of Interest would pop up. It was very easy to plot a course to different landmarks. I also found it easy to create place markers. I liked this feature and think it would be useful in creating a travel itinerary. I also enjoyed that I could take virtual tours of an area or create my own virtual tour.

    I also see how useful this app would be in primary education. I think it would help student relate to their lessons in many subjects. A teacher would find it helpful in showing the student many things. I found myself visiting and learning about many places and imagine many students would too.