A microwave radiometric landing assist system is provided which serves as an aid for landing aircraft, for example, and which may complement the present practice of using visible light sources for runway guidance. The landing assist system of the present invention involves the use of passive metallic objects positioned on the ground in a predetermined pattern. These objects are detected by a microwave radiometric receiving system located in the aircraft, and which likewise may be considered passive in that it does not radiate energy from the aircraft. The microwave radiometric landing assist system of the invention provides a display for the pilot which is analogous to the display provided by visible light sources, for example, but which is available day and night and under all types of weather conditions. The information presented to the pilot is obtained at a rapid rate over an area which includes the metallic objects pattern. The area frame rate is fast enough to allow the pilot to react properly in flying the terminal approach.
A system for displaying a landing/taxiing area as an aircraft approaches/taxis that landing/taxiing area. The system includes means on the landing/taxiing area that absorbs radar signals. The remainder of the landing/taxiing area reflects radar signals, and the system includes processors on board the aircraft or in the control tower for translating the signals and the lack of signals into a graphic representation of the landing/taxiing area. The representation changes as the orientation and position of the aircraft changes with respect to the landing/taxiing area. The system can include an autopilot control, head-up displays and memory systems. The system permits surface control by the tower.
Adding a quantity of metallic shot or particles of other materials having a high dielectric constant to the thermoplastic paint in the mixing pot of ordinary roadway marker fixation equipment, which extrudes the paint and applies same to the roadway surface, enhances the MMW radiometric visibility of the marker without adverse effect to the affixation equipment. Vehicles containing MMW radiometers directed down toward the roadway surface moves along the roadway surface is able to automatically sense microwave/millimeter wave energy from a marker in the vehicles path. In one system, the sensed energy is used in conjunction with other apparatus to assist to guide the vehicle within a traffic lane. In another system, the sensed energy is decoded and displayed as pertinent information for the vehicle's driver.
Adding a quantity of metallic shot or particles of other materials having a high dielectric constant to the thermoplastic paint in the mixing pot of ordinary roadway marker fixation equipment, which extrudes the paint and applies same to the roadway surface, enhances the MMW radiometric visibility of the marker without adverse effect to the affixation equipment. Vehicles containing MMW radiometers directed down toward the roadway surface moves along the roadway surface is able to automatically sense microwave/millimeter wave energy from a marker in the vehicles path. In one system, the sensed energy is used in conjunction with other apparatus to assist to guide the vehicle within a traffic lane. In another system, the sensed energy is decoded and displayed as pertinent information for the vehicle's driver.
A system for measuring radiant signals includes a detector circuit for detecting a time multiplexed, measured radiant signal and reference signal. A switch is connected to the detector circuit for receiving signals from the detector circuit. A measured signal sampling circuit, a reference signal sampling circuit, a measured alias circuit and a reference alias circuit are connected to the switch, which is operative for switching among the sampling and alias circuits to remove sampling noise and improve switching latency.
The attitude of a body 12 is determined, or refined, by illuminating it with a direct beam and one or more indirect beams which are reflected from a scattering surface SS, all of the beams being radiated from the same or adjacent sources. The directions of arrival of the beams are determined to allow the attitude to be determined or refined.
