Satellite radio ranging velocity navigation

A system for aiding in navigation of a marine vessel in reach of a plurality of base radio ranging stations which comprises:

• a. a radio ranging mobile station means on said vessel for generating at least two sets of radio range signals, one set for each of two base stations with each set comprising a real time series of N successive signals,
• b. comparison means connected to receive and compare each signal in each series with its next preceding signal to generate difference signals, and
• c. processing means operating on sets of said N range signals while excluding any range signal for which said difference signal exceeds a preset limit to generate signals representative of velocity of said vessel.

In an integrated satellite navigation system where satellite fixes periodically establish the position of a ship plying a course within the range of a chain of radio ranging stations and wherein ship velocities must be accurately determined in the interval between satellite fixes in order to chart said course, the method which comprises:

• a. establishing difference values between successive RF signal transit times for each of a plurality of said stations,
• b. for each of said stations storing a set of functions dependent upon successive difference values between transit times related to each said station while retaining the most recent function and discarding the most aged function in the corresponding set, and
• c. periodically generating velocity signals representative of the motion of said ship by a least mean squares utilization of said sets.

In an integrated satellite navigation system where satellite fixes periodically establish the position of a ship plying a course within the range of a chain of radio ranging stations and wherein ship velocities must be accurately determined in the interval between satellite fixes in order to chart said course, the method which comprises:

• a. establishing difference signals representative of the differences between transit times of successive Loran transmissions between said ship and each of a plurality of said stations,
• b. for each of said stations storing a set of functions dependent upon the difference signals related to each said station while retaining the most recent function and discarding the most aged function in the corresponding set, and
• c. periodically generating velocity signals representative of the motion of said ship by a least mean squares utilization of said sets.

In navigating a marine vessel in reach of a plurality of base radio ranging stations the method which comprises:

• a. generating at said vessel at least two sets of radio range signals, one set for each of two base stations with each set comprising a real time series of N successive signals,
• b. comparing each signal in each series with its next preceding signal to generate difference signals, and
• c. generating signals representative of vessel velocity utilizing sets of said N range signals while excluding any range signal for which said difference signal exceeds a predetermined limit.