Methods and apparatus for randomly modulating radar altimeters
AssigneeHoneywell International Inc.
InventorsLavell Jordan, James R. Hager
Life of this patent
Estimating the term…
Abstract
A method for randomly phase modulating a radar altimeter is described. The method includes momentarily applying a signal from a random noise source to an amplifier, applying an output of the amplifier to a voltage controlled oscillator (VCO), applying an output of the VCO to a transmitter and mixer of the radar altimeter to modulate transmissions of the radar altimeter and to demodulate reflected radar transmissions received by the radar altimeter and holding the output of the amplifier constant from before a radar altimeter transmission until after reception of the reflected radar signals from that transmission by the radar altimeter. The method further includes repeating the applying steps and the holding step.
Claims25
A method for randomly phase modulating a radar altimeter, said method comprising:
- a) momentarily applying a signal from a random noise source to an input of an amplifier;
- b) applying an output of the amplifier, the output based on the random noise input, to a voltage controlled oscillator;
- c) applying an output of the voltage controlled oscillator to a transmitter and mixer of the radar altimeter to modulate transmissions of the radar altimeter and to demodulate reflected radar transmissions received by the radar altimeter;
- d) holding the output of the amplifier constant from before a radar altimeter transmission until after reception of the reflected radar signals from that transmission by the radar altimeter;
- and
- e) repeating steps a), b), and d).
A method for randomly phase modulating a radar altimeter, the radar altimeter including a voltage controlled oscillator having an output which modulates transmissions of the radar altimeter and demodulates reflected radar transmissions received by the radar altimeter, said method comprising:
- configuring the voltage controlled oscillator to provide a random phase modulation source;
- and
- holding the phase of the modulation source substantially constant from a time when the radar altimeter transmits a radar signal until a time when a reflection of the transmitted radar signal is received by the radar altimeter.
A radar altimeter comprising:
- a voltage controlled oscillator for modulating transmissions of said radar altimeter and demodulating reflected radar transmissions received by said radar altimeter;
- a random noise source;
- a holding circuit configured to sample a voltage from said random noise source and hold the voltage constant at an input to said voltage controlled oscillator from the time a signal is transmitted by said radar altimeter until a reflected radar return signal is demodulated by said radar altimeter.
A radar altimeter comprising a voltage controlled oscillator for modulating transmissions of said radar altimeter and demodulating reflected radar transmissions received by said radar altimeter, said voltage controlled oscillator configured to randomly phase modulate the transmissions of said radar altimeter, said voltage controlled oscillator comprising an amplifier therein.
A circuit for randomly phase modulating transmissions of a radar altimeter and demodulating reflected radar transmissions received by the radar altimeter, the radar altimeter including a voltage controlled oscillator, said circuit connected to an input of the voltage controlled oscillator, said circuit comprising:
- a random noise source;
- an amplifier comprising an input and further comprising an output connected to the voltage controlled oscillator;
- and
- a switch, said switch between said random noise source and said input of said amplifier, said switch configured to be open from the time a signal is transmitted by the radar altimeter until a reflected radar return signal is demodulated by the radar altimeter.
Dependencies are inferred from the claim text.