Active Pixel Sensor Design and Operation

An active pixel sensor performs at least as well as conventional charge coupled device (CCD) imagers without drawbacks such as susceptibility to radiation damage. This active pixel sensor, which can be fabricated using an industry-standard CMOS-compatible process and smaller-sized pixels, is an integrated imaging device that is well suited for applications such as guidance and navigation in aerospace, and robot vision.

Floating Ultrasonic System

A Floating Ultrasonic System for improved nondestructive testing is based on a momentary-touching scheme where a vibrating probe comes in contact with the structure for fractions of a second while performing measurements, giving the probe the appearance of floating across a surface. The design allows for the easy movement of the probe over surfaces being inspected without the use of a liquid couplant between the probe and the surface.

Coherence Multiplexing of Wireless Surface Acoustic Wave (SAW) Sensors

This integrated, multi-sensor network quickly identifies gaseous leaks in extreme environments in ground systems, spaceflight, and space exploration by utilizing a chemical sensing film located on a piezoelectric substrate that wirelessly transmits the data collected through pairs of antennas located on the sensor. The multiplexed system is unique because it allows multiple sensors to communicate simultaneously without incurring degradation through returning signal echoes.

Magnetic Field Response Measurement Acquisition System

This measurement acquisition system uses magnetic fields to provide power to sensors and to acquire physical property measurements from them. It can make multiple measurements of different, non-related physical properties without the constraint of a limited number of data acquisition channels. The technology has been demonstrated with a leading aircraft landing gear manufacturer to wirelessly measure the fluid levels in landing gear shock struts.

Low-Frequency Portable Acoustic Measurement System

This system detects and locates atmospheric clear air turbulence using a ground-based infrasonic array to serve as an early warning system for aircraft. This system could augment existing systems such as pilot reports, airborne lidar, and airborne radar. The system has been able to detect known events such as detection of the launch of the space shuttle in Florida all the way from Virginia.

Hermetic Seal Leak Detection

This apparatus is used in nondestructive testing of hermetic seals of containers or instrumentation. It is capable of detecting both large and small leaks, and can be calibrated to characterize the relative leak rate. The technology is used in aerospace applications, food packaging, and other applications such as automotive components, semiconductors, thermostats, switches, optical devices, and harsh environment sensors.

Cryogenic and Non-Cryogenic Optical Liquid Level Instrument for Stratified Conditions

A novel process measures the liquid level in a tank. It can operate in a range of environments, including high and low temperatures and pressures. The instrument also provides far greater accuracy and faster results in cryogenic conditions than typical cryogenic liquid metering methods. It is used for cryogenic and non-cryogenic ground tank metering applications, and zero-gravity systems that include stratification or settling techniques.

Monitoring Method and Apparatus

A monitoring system includes a base station and at least one sensor unit mounted at some distance away that is in wireless, one-way communication with the base station. The sensor lies dormant until it receives a voltage trigger from a vibration-sensitive switch. When activated, the sensor takes a measurement, transmits the data to the base station, and then returns to its dormant state. The measurement taken is recorded and time stamped.

In-Situ Health Monitoring of Piezoelectric Sensors

An in-situ measurement system monitors the performance of piezoelectronic sensors, particularly accelerometers. Characteristics such as resonant frequency, response, cable status, connectivity, bonding, and linear range can be determined. Sensors can be tested in a very wide frequency range without removing them from their mounted locations, and without requiring specially constructed transducers or special wiring.