Abstract: A radio signal controlled clock which decodes time information in a radio signal and thereby determines the current time. The clock collects and stores radio signal data as soon as a reasonably decodeable radio signal is located, even before the minute boundary of the radio signal's time base has been located. This data is stored and later used for decoding and verifying the digits of the time information after the minute boundary has been located. In another aspect of the present invention, an internal counter in the clock is periodically resynchronized with the radio signal, and the average of the adjustments required for this resynchronization is maintained.

Abstract: A method and apparatus for synchronizing a clock to broadcast time-based signals, said time-based signals including encoded timing information, the method comprising the steps ofreceiving said time-based signals,decoding said time-based signals to derive a plurality of digits from said timing information representing actual clock time, andseparately verifying the correctness of each of said digits, said correctness verifying step including the steps of separately comparing each said derived digit with at least one corresponding previously decoded derived digit and verifying said derived digit when it meets a predefined verification test based on the consistency of said derived digit with said at least once corresponding previously decoded derived digit, repeating said comparison and verifying steps as said time-based signals are decoded until each said derived digit has been separately verified, and generating a lockon signal when all of said derived digits have been verified.