Calculate a baseball player's batting average. Calculating a baseball player's batting average is not a difficult task at all. A batting average represents the percentage of at bats that result in hits for a particular baseball player. The formula is: That's all there is to it.
To fly under the radar means to act in a way so as to actively avoid detection. It is the opposite of 'in your face'. There is an element of getting away with something but it is not necessarily bad.
During NOE flight, geographical features are used as cover, exploiting valleys and folds in the terrain by flying in, rather than over, them. This keeps below enemy radar coverage, avoiding skylining. Other terms are also used, including ground-hugging,  terrain masking , or flying under the radar . The older term, commonly used for fixed-wing aircraft practicing this flight tactic in the World War II era, was hedgehopping.