Meridian altitude

When we talk about meridian altitude, we are actually trying to find out how high a particular object is above, or below, an imaginary line called the horizon. The horizon is the place where we see the ground meet the sky when we look ahead of us.

Now, imagine you are standing outside on a clear day and you see an airplane flying overhead. If you were to look up directly at it, you would be looking at what is called the altitude.

However, aircraft move vast distances in very little time, so if you wanted to keep track of its height over a given area, you would need a way to measure how high it is above or below the horizon at any given time. This is where the concept of meridian altitude comes in.

The meridian is an imaginary line that runs from the north pole to the south pole and passes through the point directly above your head. By measuring the angle between the airplane and the meridian line, you can determine how high it is in the sky.

This measurement is made using specialized instruments called sextants or theodolites that are used to align the object with the meridian line and then measure the angle between them. This angle is called the meridian altitude, and it tells us how high or low the object is in the sky at that specific moment.

So, to sum it up, meridian altitude is the height of an object in the sky above or below an imaginary line called the horizon, measured by the angle between the object and an imaginary line called the meridian.