Digital radar altimeter

摘要

A method for determining a height above ground of an aircraft broadly comprises the steps of generating a transmit signal with a transmitter, transmitting the transmit signal with a first antenna, generating a local oscillator signal with a local oscillator, receiving a receive signal with a second antenna, mixing the receive signal with the local oscillator signal to generate a baseband signal, determining a frequency of interest of the baseband signal, and calculating an aircraft altitude corresponding to the frequency of interest.

主权项

1. A method for determining a height above ground of an aircraft, the method comprising the steps of:
generating, using a local oscillator linear sweep generator, a local oscillator signal that is swept over a frequency range; generating, using a transmitter linear sweep generator, a transmit signal with a transmitter that is swept over the frequency range and delayed in time with respect to the local oscillator signal; transmitting the transmit signal with a first antenna; receiving a receive signal with a second antenna; mixing, using a mixer, the receive signal with the local oscillator signal to generate a baseband signal having a frequency of interest for calculating an aircraft altitude; adjusting, using a controller, the delay in time while the aircraft is on the ground until the frequency of interest is at least equal to a minimum difference frequency; and calculating, using the controller, the aircraft altitude based on the frequency of interest determined from the receive signal and the local oscillator signal.