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US 3,943,508 AGranted
Electronic roll compensation system for a radar antenna
AssigneeHughes Aircraft Company
InventorsRobert J. Boucher, Robert L. Brackney, Jr.
Life of this patent
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AssigneeHughes Aircraft Company
InventorsRobert J. Boucher, Robert L. Brackney, Jr.
Estimating the term…
A simplified and reliable system for electronically controlling the angular position relative to an antenna axis of the ground areas from which radar signals are received and processed so that air-to-ground range may be measured accurately regardless of the roll angle of the aircraft in which the radar is mounted. In a radar silent lobing system in which lobing is done on reception of the transmitted signals, the roll compensation system provides direct current signals which are proportional to the sine and cosine of one-half the roll angle and which are selectively applied to the pole pairs of the azimuth and elevation poles of the ferrite modulator that is utilized in the lobing system. During range determining operations, first and second pole pairs each of an azimuth and elevation pole, or group of azimuth and elevation poles, are energized or selected during alternate lobing or pulse repetition frequency intervals. The system functions at any roll angle .alpha. by positioning the magnetic field of the modulator at .alpha./2 degrees so as to shift the components of the modulator input so that the vector sum at the output will be vertical, resulting in a constant output being provided to the radar receiver regardless of the roll angle of the aircraft.
A roll angle correction system for a radar system operating at a pulse repetition frequency and having a modulator with a rotating field for space rotating received elevation and azimuth difference signals, said modulator having azimuth and elevation poles to form a first group of azimuth and elevation poles and a second group of azimuth and elevation poles comprising
A roll angle compensation system for a radar system having a rotatable ferrite modulator responsive to difference signals from an antenna and including a first azimuth and elevation pole pair and a second azimuth and elevation pole pair, said modulator having a polarized output, said radar system having a source of timing pulses and a source of roll angle signals comprising
In a radar system operating at a pulse repetition frequency having a sum and difference network with outputs providing first and second difference signals and a sum signal, modulating means coupled to said first and second difference outputs for rotating the first and second difference signals in space quadrature and for coupling the rotated signals to an output terminal with a selected polarization, said modulation means having first and second elevation pole means and first and second azimuth pole means for respectively controlling the elevation and azimuth vectors of the rotating field, coupler means coupled to the output terminal of said modulator and coupled to the sum output of said sum and difference network for receiving said sum signal and processing means coupled to coupler means for alternately switching between pulse repetition frequency intervals to an upper and lower storage element the signal provided by said coupler means and comparing said storage elements to provide a signal representative of the time of occurrence of the elevation boresight and determining range at said elevation boresight, said system having a source of aircraft roll signals .alpha., a roll compensation system comprising
An antenna roll compensation system in a radar system having a rotatable modulator for rotating elevation and azimuth difference signals in response to first and second groups of windings and having a source of roll angle signals and pulse repetition frequency signals comprising
Dependencies are inferred from the claim text.