Abstract: A method of removing undesired signals in an aviation guidance system may include receiving at least one first desired signal having a first frequency of amplitude modulation, receiving at least one second desired signal having a second frequency of amplitude modulation, and receiving at least one undesired signal having any frequency including a frequency that is substantially the same as or a subharmonic of at least one of the first and second desired signals. The first and second frequencies of amplitude modulation are phase synchronous, and the undesired signals are non-synchronous with at least one of the first and second desired signals. The method may also include identifying the undesired signals and removing the undesired signals.

Abstract: Signal processing systems for radar installations are provided for simultaneous processing of one or more IF signals of dynamically varying frequency and bandwidth with a single analog signal path. The signal processing system includes, but is not limited to, a converter configured to digitize a return signal resulting in a digitized broadband signal, and a signal processor coupled to the converter. The signal processor includes a digital filter having a center frequency and a bandwidth, and the digital filter is configured to select a signal from the digitized broadband signal. The selected signal has a center frequency. The signal processor is configured to match the center frequency of the digital filter with the center frequency of the selected signal, and adjust the bandwidth of the digital filter based on the selected signal.

Abstract: An avionics display (10) for use in an aircraft navigation system including a navigation receiver. The avionics display (10) includes a needle (12) for indicating the position, heading, glide slope or other navigational parameter of the aircraft and a stepper motor (14) coupled with the needle and responsive to the navigation receiver for driving the needle in response to the navigation signals received by the receiver. The stepper motor drives the needle at a much higher torque than prior art displays and is therefore less sensitive to contaminates and magnetic interference and is less fragile.

Abstract: A display apparatus (10) having a display (12) including indicia representative of a measured parameter, an indicator (13) shiftable relative to the display, and a control assembly (14) for controlling the positioning of the indicator relative to the display. The control assembly includes a microprocessor (16) for receiving navigational signals and for converting the navigational signals to control signals and a stepper motor (18) responsive to the microprocessor for driving the indicator in response to the control signals. The control assembly also includes an indicator position sensor (20) for determining the actual position of the display indicator and for generating position signals representative of this actual position. The microprocessor uses these position signals for calibrating the stepper motor.