Automatic mode control for a parachutist navigation system

A method of identifying operational modes experienced by a user during a jump from an aircraft, comprising:

• estimating, by a navigator device, a user altitude and a user descent rate, based on a set of navigation state data vectors sampled according to a sampling interval;
• determining, by a computer-based jump determination module, that the user is ready to transition from a flight mode to a descent mode, but not yet in decent mode, when:
• the user altitude is above a jump altitude threshold, the jump altitude threshold being an altitude below which a jump should not be attempted;
• and
• a variation of the user altitude is below a predetermined altitude variation threshold;
• after determining that the user is ready to transition from the flight mode to the descent mode, determining, by the computer-based jump determination module, that the user has transitioned from a flight mode to a descent mode when:
• a user ground speed is below a ground speed threshold;
• and
• one or both of (i) a GNSS position error estimate, and (ii) the user descent rate estimate, indicates a jump signature;
• and
• receiving, by a multipurpose navigation system, information transmitted from the computer-based jump determination module about the transition from the flight mode to the descent mode, and changing a display presented by a display device associated with the multipurpose navigation system based on the information.