Geodetic datum

High school (ages 12+)
Geography

Name:

Date:

Step 1 · Read the article

Open the article and read it at the level above. Then answer the questions below in your own words.

https://smallwhale.org/articles/geodetic-datum

Write what each word means, using the article.

Do not copy the article. Write two things you learned, the way you would explain them to a friend.

Answers below are taken from the article’s stored facts, so they match what the student read.

1. What is a geodetic datum?A geodetic datum is a 3‑dimensional coordinate system that tells us exactly where we are on Earth. It uses a reference ellipsoid to approximate the planet’s shape.
2. Why do we need different datums for different places?Early datums were made for specific regions and fit those areas well, but they didn’t match other parts of the world because Earth’s shape changes across the globe.

Geoid: The irregular shape of the Earth defined by equipotential surfaces of gravity, approximating mean sea level.
Ellipsoid of Revolution: A spheroid generated by rotating an ellipse about its minor axis, used as a mathematical model for Earth.
Coordinate Transformation: Mathematical procedures to convert coordinates from one reference system or datum to another.