/**
  * Geometric constants used in navigation computations in
    classes within Rob's Moving Map package.

  * @author Robert J Morton YE572246C
  * @version 15 January 1998 */

interface navconst {
  double
    π = Math.PI,              // the circular constant
    Twoπ = π + π,             // radians per complete turn
    πBy2 = π / 2,             // radians per right-angle
    SPR = 648000 / π,         // seconds of arc per radian
    DPR = 57.2957795141996,   // number of degrees per radian
    TenDeg = 10 / DPR,        // 10 degrees in radians
    KPR = 6366.197723857773,  // An earth-radian in kilometres
    KphRps = KPR * 3600,      // An earth-radian/second in km/hr
    TkphRPS = 1000 / KphRps;  // 1000kph in radians per second
}