docs: public static double alongTrackDistanceRad(double lat1, double lon1, double lat2, double lon2, double latQ, double lonQ) {
      // TODO: inline and share some of the trigonometric computations!
      double dist1Q = haversineFormulaRad(lat1, lon1, latQ, lonQ);
      double ctd = crossTrackDistanceRad(lat1, lon1, lat2, lon2, latQ, lonQ, dist1Q);
      return alongTrackDistanceRad(lat1, lon1, lat2, lon2, latQ, lonQ, dist1Q, ctd);
    }