#ifndef POSITION_H

#define POSITION_H

#include "Vector.h"

//#include "TObject.h"

////////////////////////////////////////////////////////////////////////////////////////////////

//class Position:

//This class is a 3-vector that represents a position on the Earth's surface.

//

// Methods:

//

// Lat() : Returns latitude of this position.

//

// Lon() : Returns longitude of this position.

//

// Distance(second position) : Returns distance between this position and a second. Takes

// a Position as input.

//

// SurfaceDistance(second position, surface elevation) : Returns distance over the surface of

// the Earth between the spot on the surface under/above this position and the spot

// under/above a second position.

// Input: a Position, and the distance from the center of the Earth to the surface at

// this Position.

//

////////////////////////////////////////////////////////////////////////////////////////////////

//class Position : public Vector, public TObject {

class Position : public Vector {

public:

Position();

//Default constructor: calls default constructor of Vector

Position(Vector vec);

Position(double theta_inp, double phi_inp);

//Identical to the Vector constructor with the same inputs.

Position(double longitude, double latitude, double altitude);

//Constructs a position vector given a longitude, latitude,

//and distance from the center of the Earth.

double Lat() const;

//Returns latitude, where the +z direction is at 0 latitude.

double Lon() const;

//Returns longitude, where 0 degrees longitude corresponds to phi = 270 deg (-y axis),

//and increases clockwise.

//Hence, lon=0 -> phi=270,

//lon=90 -> phi=180,

//lon=180 -> phi=90,

//lon=270 -> phi=0,

double Distance(const Position &second) const;

//Returns chord distance (direct distance between two vectors)

double SurfaceDistance(const Position &second, double local_surface) const;

//Returns "surface distance" between two positions. The surface distance

//is the the length of arc between two positions.

//Altitude (i.e. length of the position vector) is irrelevant; only angle

//between the two position vectors is considered.

ClassDef(Position,1);

}; //class Position

#endif //POSITION_H