Abstract: A method for incorporating a forward ranging feature into a radar altimeter is described. The method comprises positioning an antenna of the altimeter such that a side lobe of a radar signal radiates from the antenna in a forward direction and processing a radar return from the side lobe to determine a range to a forward object.

Abstract: A method for incorporating a forward ranging feature into a radar altimeter is described. The method comprises positioning an antenna of the altimeter such that a side lobe of a radar signal radiates from the antenna in a forward direction and processing a radar return from the side lobe to determine a range to a forward object.

Abstract: An antenna is described which includes first, second, and third conductive layers and a first and second laminate to separate the layers. The laminates are configured with plated through holes to provide contact between the first and third layers, the holes defining antenna cavities, the second conductive layers being the antenna. A plurality of slots in the first conductive layer align within the defined antenna cavities, further defining the antenna cavities for the second conductive layer.

Abstract: An antenna is described which includes first, second, and third conductive layers and a first and second laminate to separate the layers. The laminates are configured with plated through holes to provide contact between the first and third layers, the holes defining antenna cavities, the second conductive layers being the antenna. A plurality of slots in the first conductive layer align within the defined antenna cavities, further defining the antenna cavities for the second conductive layer.

Abstract: A radar altimeter for determining altitude of an air vehicle with respect to ground comprises a digital sequencer for digitally modulating a first signal. A transmitter coupled to the digital sequencer transmits a radar signal including the modulated first signal toward the ground. A receiver receives a reflected radar signal from the ground. The received radar signal includes the modulated first signal. A digitizer coupled to the receiver generates digital samples of the modulated first signal. A digital signal processor coupled to the digitizer receives digital samples of the modulated first signal from the digitizer, demodulates the received digital samples, processes the demodulated digital samples and outputs altitude data based on the demodulated digital samples.