Orthometric height

Orthometric height is a way of measuring how high something is above sea level. Imagine you are standing on the beach and you want to know how high a mountain is. You might think of measuring how far you need to climb to get to the top, but that measurement wouldn't tell you how high the mountain really is. That's because the height of the mountain above the ground can change depending on the shape of the ground.

Instead, we use orthometric height, which takes into account the shape of the ground and the distance from the mountain to the sea. It's like taking a snapshot of the mountain's height and locking it in place, no matter what happens to the ground beneath it.

To measure orthometric height, we first need to know our starting point - this is sea level. Sea level is like a "base" that we use to measure everything else. We then use a device called a barometer to measure air pressure at the base and at the top of the mountain. If the air pressure is lower at the mountain than at sea level, that means the mountain is higher than sea level. We can then use some math to figure out exactly how high it is.

So, in short, orthometric height is a way of measuring how high something is above sea level, taking into account the shape of the ground and the distance from the object to the sea. It helps us get an accurate understanding of how tall things really are!