Keyword: Noise

Briefs: Photonics/Optics

A complementary metal oxide/semiconductor (CMOS) focal-plane readout circuit for an imaging array of long-wavelength infrared (LWIR) photodetectors effects in-pixel current-mode...

Briefs: Information Technology
Strategies for Optimal Placement of Sensors and Actuators

A paper presents a survey of sensor- and actuator-placement problems from various applications that involve a wide range of engineering disciplines. "Smart" structures that contain sensors (e.g., microphones or strain sensors) and actuators (e.g., loudspeakers or piezoelectric actuators)...

Briefs: Photonics/Optics
High-Speed Image Detectors With Subelectron Noise Floors

Parallel ultra-low-noise hybrid detectors (PHUDs) are developmental image-detector devices for use in low-power, scientific-grade video cameras. The hybrid nature of a PHUD lies in the incorporation of both charge-coupled-device (CCD) image-detection circuitry and complementary metal...

Briefs: Photonics/Optics

Photomultiplier tubes (PMTs) have long been recognized as the detector of choice for very weak light detection. The high gain of the PMT, in excess of 10 ×106, makes...

Briefs: Software

Automotive interior noise has become a critical consideration for manufacturers. Many studies have shown that interior noise in a vehicle has a major impact on the customer's perception of...

Briefs: Mechanical & Fluid Systems
Experiments on Vibration and Noise in Fuselages

A paper summarizes a continuing program of vibro-acoustic testing of two aircraft fuselage structures: (1) a 12-ft (3.7-m)-long generic aluminum test-bed cylinder that contains stiffening rings and stringers and (2) the 40-ft (12.2-m)-long fuselage of a 10-passenger turboprop airplane, made of...

Briefs: Photonics/Optics

There are a number of important OEM photonic applications based on the detection of low incident light levels, including flow cytometry, PET (positron emission tomography) imaging,...

Briefs: Software
Updated Software for Predicting Noise From Aircraft

The FOOTPR and RADIUS computer programs implement state-of-the-art mathematical models for predicting levels of noise generated by existing or proposed aircraft. These programs can be used to calculate Federal Aviation Administration (FAA) noise-certification levels, airport-vicinity noise...

Briefs: Physical Sciences

Improved sensor assemblies have been invented for measuring acoustic signals in gases or liquids flowing in or around any of a variety of moving or stationary objects. Examples of such objects...

Briefs: Information Technology

A method for detecting and characterizing faults in a rotating machine involves analysis of selected aspects of the evolution of the spectral distribution function (SDF) of...

Briefs: Mechanical & Fluid Systems

Streamlined fairings have been invented for housing single or multiple microphones to measure noise in flowing gases and liquids. Each fairing of this type is designed to minimize the...

Briefs: Software
Software Detects Small Satellites in Spacecraft Imagery

A computer program processes images acquired at different times by instrumentation aboard a spacecraft to detect small satellites of asteroids and other planetary bodies. The program coregisters the images, removes instrument artifacts and images of background stars, and performs a...

Briefs: Mechanical & Fluid Systems
Improved Mufflers for General Aviation

Innovative designs of mufflers for engines of small airplanes have been investigated in an effort to satisfy conflicting demands to maximize the reduction of exhaust noise while minimizing back pressure, size, and weight. Automotive-type muffler designs are not suitable for this purpose because they entail...

Briefs: Electronics & Computers

An electronic engine-health-monitoring system is based on (1) computation of frequency-phase-normalized (FPN) spectra from the digitized outputs of vibration sensors and (2) the use of...

Briefs: Electronics & Computers
SQUID-Based Asymmetric Planar Gradiometer

Berkeley Laboratory researchers have demonstrated a novel superconducting gradiometer that helps to reduce ambient magnetic field noise generated by relatively distant sources in favor of tiny magnetic signals generated by a local source. This is another step toward the operation of SQUID-based...

Briefs: Electronics & Computers

An improved type of optoelectronic oscillator is based on Brillouin amplification. An oscillator of this type converts light energy into an electro-optical oscillation, typically at a...

Briefs: Information Technology

An improved method of analysis and design offers the potential to enhance the performances of adaptive feedforward tracking systems. The method can, in principle, make it possible to...

Briefs: Electronics & Computers

Hybrid high-temperature-superconductor (HTS)/semiconductor planar oscillator circuits that operate at a frequency of 8.4 GHz have been developed. In the original intended application,...

Briefs: Electronics & Computers

An algorithm estimates the Doppler frequency shift in a received radio signal with square-wave-pulse binary differential-phase-shift-keyed (DPSK) modulation. [With little...