Abstract: An air data system and method for a rotary aircraft is described. The air data system includes a plurality of flush ports connected via tubing to a plurality of air flow sensors that can measure air flow speeds as low as approximately 0.02 knots. The flush ports are arranged around a main rotor shaft and below a rotor hub of the rotary aircraft to help reduce the impact of rotor downwash. The flush ports and tubing permit air to flow into the air flow sensors, which allows the plurality of air flow sensors to measure speed and direction of cross-wind components of air flow surrounding the rotary aircraft.

Abstract: A vehicle detecting system and method for use on a specific location such as an airport, including a sensor string nominally perpendicular to the direction of vehicle travel at the location. The sensor string includes at least one magnetic field sensor and a transmitter for transmitting signals from the at least one sensor to a monitoring point. A plurality of sensors is preferred. The transmitter includes a control unit for receiving the signals and a sender for sending the signals to the monitoring point. The preferred magnetic field sensor is a magnetoresisteive sensor having a field range of at least ±5 gauss. A preferred location for the sensor string is in a groove in the surface.

Abstract: A differential pressure-induced airflow based approach is used to measure Angle-Of-Attack (AOA) or Angle-Of-Sideslip (AOS) for an aircraft. Ports on opposing sides of an aircraft fuselage are coupled by an airway incorporating a mass airflow sensor. As the relative wind's angle of incidence changes direction with respect to the aircraft's longitudinal axis or wing chord, a differential pressure is created. The differential pressure induces an airflow between the ports whose magnitude is measured by a mass airflow sensor. The resulting airflow is a function of the respective AOA or AOS. The measured airflow and air data computer supplied parameters of airspeed (or dynamic pressure) and altitude (or static pressure) are utilized by an algorithm that reduces the data into angular AOA or AOS measurements.

Abstract: An air data sensor for an aircraft has a flush mounted plate at the outside surface of the aircraft and a housing for the sensor within the aircraft below the plate. A plurality of holes in the plate provide air flow to a pressure sensor in the housing. To prevent water from reaching the sensor, a trap chamber is provided below the holes. Various contorted air flow paths are disclosed. The tube to the pressure sensor may be heated.

Abstract: A vehicle detecting system and method for use on a specific location such as an airport, including a sensor string nominally perpendicular to the direction of vehicle travel at the location. The sensor string includes at least one magnetic field sensor and a transmitter for transmitting signals from the at least one sensor to a monitoring point. A plurality of sensors is preferred. The transmitter includes a control unit for receiving the signals and a sender for sending the signals to the monitoring point. The preferred magnetic field sensor is a magnetoresisteive sensor having a field range of at least ±5 gauss. A preferred location for the sensor string is in a groove in the surface.

Abstract: An air data sensor for an aircraft has a flush mounted plate at the outside surface of the aircraft and a housing for the sensor within the aircraft below the plate. A plurality of holes in the plate provide air flow to a pressure sensor in the housing. To prevent water from reaching the sensor, a trap chamber is provided below the holes. Various contorted air flow paths are disclosed. The tube to the pressure sensor may be heated.

Abstract: A magnetometer vehicle detector for detecting various parameters of traffic on a roadway. A number of sensors, having a compact package, along with connecting cables, may be placed in road way with a small number of standard width sawcuts. Alternatively, sensors may be placed in the roadway within tubes under the external surface of the roadway. The package design of the sensor is such that the sensor can be placed in the sawcut or tube only in a certain way or ways resulting in the most sensitive axis of the sensor being most likely affected by just the traffic or vehicles desired to be detected and measured. The sensor may be a magnetoresistive device having a permalloy magnetic sensing bridge. Multiple sensors may be placed in single or multiple lanes of the roadway for noting the presence of vehicles and measuring traffic parameters such as average speeds, vehicle spacings, and types and numbers of vehicles.

Abstract: A switched-magnetization closed-loop magnetometer having a magnetoresistive bridge for sensing external magnetic fields. The output signal from the bridge to an amplifier, is magnetically nulled by a feedback coil. Each of the bridge elements have a magnetic easy axis that is periodically and magnetically flipped by a reset coil. The output of the amplifier goes to an analog switch and an integrator in one or the other order. The output of the analog switch or the integrator may go on to a sample and hold circuit, or other sampling device, that alternately samples the output to it in synchronism with the reset coil. The output is processed by a low pass amplifier. A clock provides signals to the reset coil, the analog switch and the sample and hold switch.

Abstract: A passive ring resonator gyro is constructed of an electromagnetic waveguide ring path which causes a specified rotation of the polarization of the waves, once for each round trip through the ring path. For an optical fiber ring path, a splice at some point is introduced in the ring path in which the fiber ends are rotated relative to each other in order to effect polarization rotation.