Astrogeodetic levelling

Astrogeodetic leveling is a way to measure how high or low the ground is using really cool space technology! First, we need a special device called a geodetic instrument that can measure the angles of the stars and the moon. This works because the stars and the moon always stay in the same place in the sky, so we can use them to know when the instrument is level.

Next, we take a bunch of measurements of the angles of the stars and the moon at different points on the ground. We then use complicated math to figure out how high or low each point is compared to the other points. This lets us make a map of the area that shows us how the ground is shaped.

The reason people use astrogeodetic leveling is because it can give us really accurate measurements over long distances. This is great for things like building roads or bridges because we need to know how the ground changes as we go along.

So, in simple terms, astrogeodetic leveling is like using space technology to see how high or low different parts of the Earth are so we can make sure everything is built on solid ground. Cool, huh?