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AssigneeGarmin Ltd.
InventorsLawrence W. Beason, Ronald T. Chinnery, Stephen Davis, Jay Dee Krull
Estimating the term…
A device and method for compensating a crystal oscillator that is not electrically compensated over its operable temperature range. A GPS receiver device stores in memory data indicative of the actual offset frequency of oscillation of the crystal over its operable temperature range. The first time the device is activated, the temperature at the crystal is sensed and data, stored in memory, indicative of the specified frequency offset of the crystal at the sensed temperature is retrieved, and used to control the receiver.backslash.decoder. When the receiver locks onto a sufficient number of satellites to calculate its two-dimensional location, the actual frequency offset of the crystal is calculated and stored in memory. Repeated use of the receiver device permits a database of actual frequency offset data of the crystal, over its operable temperature range to be stored. Subsequent uses of the device permit retrieval of this data for use in locking the receiver onto satellite signals. If such data is not available, the device uses the average offset data at the given temperature. The device further adjusts the offset data originally retrieved or computed until the receiver locks onto the desired signal.
A GPS satellite receiver device for locking to a signal transmitted from a satellite, the GPS receiver device comprising:
A GPS satellite receiver device for locking to a signal transmitted, at a selected frequency, from a satellite, the GPS receiver device comprising:
A method of calibrating a crystal oscillator in a GPS receiver device having a memory, the receiver for locking onto a signal transmitted from a satellite, the crystal oscillator having a crystal with specified offset frequency characteristics over an operable temperature range, the method comprising:
Dependencies are inferred from the claim text.