import static java.lang.Math.sin;
import static java.lang.Math.cos;
import static java.lang.Math.acos;

public class AzimuthalEquidistantProjection
{
	/* Instance Variables */
	private final double α0;
	private final double δ0;
	
	/*== Constructors ==*/
	public AzimuthalEquidistantProjection( final RightAscension CENTER_RA,
										   final Declination CENTER_DEC )
	{
		α0 = CENTER_RA.toRadians();
		δ0 = CENTER_DEC.toRadians();
	}
	
	/*== Accessors ==*/
	public double[] getXY( final RightAscension RA, final Declination DEC  )
	{
		/* Local Constants */
		final double α = RA.toRadians();
		final double δ = DEC.toRadians();
		final double K;
		final double COS_C;
		final double C;
		
		/* Local Variables */
		double[] xy = new double[2];
		
		/* Calculate x and y Coordinates */
		COS_C = sin(δ0)*sin(δ) + cos(δ0)*cos(δ)*cos(α - α0);
		C = acos(COS_C);
		K = C / sin(C);
		xy[0] = K * cos(δ)*sin(α - α0);
		xy[1] = K * ( cos(δ0)*sin(δ) - sin(δ0)*cos(δ)*cos(α - α0) );
		
		return xy;
		
		/*
		 * See here:
		 * http://mathworld.wolfram.com/AzimuthalEquidistantProjection.html
		 */
	}
}

Create AzimuthalEquidistantProjection.java