Centripetal acceleration determination, centripetal acceleration based velocity tracking system and methods

An apparatus for determining an airspeed of an aircraft in flight during a turn, said apparatus comprising:

• a GPS receiver for characterizing the flight of the aircraft in terms of Earth-based reference system data for a first position and a second position of the aircraft that are separated by a time increment;
• a processor configured for
• determining a centripetal acceleration based on the Earth-based reference system data for the first and second positions in conjunction with the time increment,
• establishing a rate of rotation corresponding to the time increment in an aircraft-based reference system, and
• determining the airspeed based on the centripetal acceleration and the rate of rotation.

A method for monitoring the flight of an aircraft, the aircraft carrying a GPS system which outputs GPS data as a series of GPS packets for selective use as Earth-based reference system data, said method comprising:

• periodically monitoring at least selected ones of the series of GPS packets to serve as the Earth-based reference system data for detecting that the aircraft is engaged in a turn based on a track angle that forms part of each GPS packet;
• detecting a turn as characterized by a change in the track angle from a prior packet corresponding to a prior position of the aircraft to a new packet corresponding to a new position of the aircraft;
• determining a centripetal acceleration based on the prior packet, the new packet and a time increment that separates the prior packet and the new packet;
• establishing a rate of rotation corresponding to the time increment in an aircraft-based reference system;
• and
• determining the airspeed based on the centripetal acceleration and the rate of rotation.

An instrument, comprising:

• a GPS receiver for characterizing the movement of a craft that is supported by a moving ambient in terms of Earth-based reference system data for a first position and a second position of the craft that are separated by a time increment;
• at least a selected one of a heading gyro to provide a heading output for tracking a heading of the craft in a craft-based reference system and a rate sensor for monitoring a rate of change of a yaw orientation of the craft in the craft-based reference system;
• a processor configured for
• determining a centripetal acceleration based on the Earth-based reference system data for the first and second positions in conjunction with the time increment,
• establishing a rate of rotation corresponding to the time increment in the craft-based reference system based on the heading output if the heading gyro is selected or based on the rate of change of the yaw orientation if the rate sensor is selected, and
• determining a velocity of the craft in a turn relative to the moving ambient based on the centripetal acceleration and the rate of rotation.

A method for monitoring the flight of an aircraft, the aircraft carrying a GPS system which outputs GPS data as a series of GPS packets, said method comprising:

• a) at least periodically monitoring selected ones of the series of GPS packets for detecting that the aircraft is engaged in a turn based on a track angle that forms part of each GPS packet as characterized by a change in the track angle from a prior packet corresponding to a prior position of the aircraft to a subsequent packet corresponding to a subsequent position of the aircraft;
• b) responsive to detecting a turn, determining a centripetal acceleration of the aircraft based on the prior packet, the subsequent packet and a time increment that separates the prior packet and the subsequent packet;
• c) establishing a rate of rotation of the aircraft corresponding to the time increment in an aircraft-based reference system;
• and
• d) determining an airspeed of the aircraft based on the centripetal acceleration and the rate of rotation.

A method for monitoring the flight of an aircraft, said method comprising:

• periodically monitoring a change in a yaw orientation of the aircraft;
• performing a turn detection procedure based at least in part on a current value of the change in the yaw orientation;
• responsive to detecting a turn, characterizing the flight of the aircraft in terms of Earth-based reference system data for a first position and a second position of the aircraft that are separated by a time increment;
• determining a centripetal acceleration of the aircraft based on the Earth-based reference system data for the first and second positions in conjunction with the time increment;
• establishing a rate of rotation corresponding to the time increment in an aircraft-based reference system;
• and
• determining an airspeed of the aircraft based on the centripetal acceleration and the rate of rotation.