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AssigneeInternational Standard Electric Corporation
InventorsFrancis G. Overbury, Paul Barton, Kevin M. Kelly
Estimating the term…
A signal processing arrangement, particularly for Doppler ILS, giving complete scanning verification and tracking filter operation. Two commutated filters are driven by two voltage controlled oscillators whose roles are interchangeable. One filter is used solely for information signal tracking and the other solely for scanning. If the true signal is being tracked, the peak output from the scanning filter corresponds in amplitude and frequency to this signal and occurs at the same time as the frequency coincidence of the two oscillators. If the incorrect signal is being tracked, there is non-correspondance between the peak output and the signal being tracked. This is detected and the roles of the oscillators are interchanged, causing the oscillator which was scanning to reside on the correct signal and the other oscillator to adopt the scan program.
In a Doppler Navigation receiver for deriving angular position information from received signals transmitted from a remote commutated array ground beacon, signal processing apparatus for frequency tracking the direct path signal and avoiding the tracking of frequencies corresponding to multipath signals, comprising:
Dependencies are inferred from the claim text.