"In mathematics, a Costas array can be regarded geometrically as a set of n points lying on the squares of a n\u00D7n checkerboard, such that each row or column contains only one point, and that all of the n(n \u2212 1)/2 displacement vectors between each pair of dots are distinct. This results in an ideal 'thumbtack' auto-ambiguity function, making the arrays useful in applications such as sonar and radar."@en .