I am working on a project in advanced java using netbeans in which i need to calculate the latitude and longitude of an airport into cartesian coordinates.

note: Java =/= JavaScript.

second, for the conversion you need to know a little bit more:

- where is the point-of-origin of the cartesian coordinate system?

- you also need the distance from the point-of-origin in the polar coordinate system (lattitude and longitude alone do not define a point, the define a line)

ideas for the conversion you will find in Wikipedia.

how should i calculate coordinates of two airplanes when they are flying so that i can restrict them from colliding each other?

vectorial Maths.