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US 3,940,763 AGranted
Digital tacan system
AssigneeThe Singer Company
InventorRonald Y. Paradise
Life of this patent
Estimating the term…
Abstract
A digital tacan system which provides improved bearing and range accuracy and allows faster acquisition. In computing, both bearing and range updates are maintained current using a Kalman filter. Portions of the computation may be performed in an on-board computer with the remainder done is a special purpose computer capable of being implemented using a few custom made MOS/LSI chips.
Claims11
Apparatus to receive and decode a Tacan bearing signal comprising:
- a. an antenna;
- b. an RF and detector stage coupled to said antenna;
- c. a matched filter having the output of said RF and detector as an input;
- d. means coupled to the output of said filter to detect the time arrival of each signal pulse and to provide an output indicative thereof;
- e. means to detect the amplitude of each signal pulse and to provide an output indicative thereof;
- f. means coupled to the output of said filter to detect the time of arrival of a reference pulse and to provide an output indicative thereof;
- and
- g. digital computing apparatus having as inputs the output of said means to detect the time of arrival of each signal pulse, means to detect the amplitude of each signal pulse and means to detect the time of arrival of a reference pulse, said digital computing means programmed to:
- 1. compute from the time of arrival of said reference pulses using a first Kalman Filter, the estimated frequency and phase of the transmitted signal;
- 2. compute from the frequency, the amplitude and the estimated frequency, using a second Kalman Filter, an estimate of the state variables of the bearing signal;
- and
- 3. compute from said state variables and the estimated phase, the bearing of the receiver with respect to the transmitting station.
9 more elements
A method of determining a Tacan bearing comprising:
- a. receiving the Tacan pulses transmitted by a Tacan station;
- b. determining the time of arrival of each pulse and its amplitude;
- c. determining the time of arrival of each reference pulse;
- d. computing from the time of arrival of said reference pulses in a first Kalman Filter the estimated frequency and phase of the transmitted signal;
- e. computing from the frequency, the amplitude, and the estimated frequency, in a second Kalman Filter, an estimate of the state variables of the bearing signal;
- f. computing, from said state variables and the estimated phase, the bearing of the receiver with respect to the transmitting station.
3 more elements
In a Tacan receiver, means to decode the Tacan bearing comprising:
- a. means to detect the time of arrival of each signal pulse and to provide an output indicative thereof;
- b. means to detect the amplitude of each signal pulse and to provide an output indicative thereof;
- c. means to detect the time of arrival of a reference pulse;
- d. digital computing apparatus having as inputs the output of said means to detect the time of arrival of each signal pulse, means to detect the amplitude of each signal pulse and means to detect the time of arrival of a reference pulse, said digital computing means programmed to:
- 1. compute from the time of arrival of said reference pulses using a first Kalman Filter, the estimated frequency and phase of the transmitted signal;
- 2. compute from the frequency, the amplitude and the estimated frequency, using a second Kalman Filter, an estimate of the state variables of the bearing signal;
- and
- 3. compute from said state variables and the estimated phase, the bearing of the receiver with respect to the transmitting station.
5 more elements
Dependencies are inferred from the claim text.