In many fields of spectroscopy, classification of the measured multivariate response is not always a straightforward process. Accurate classification is limited by many factors that are highly dependent upon the spectroscopy method being utilized. In all cases, however,...

One of the more critical constraints to the continued growth of air traffic is the related concern regarding aircraft noise. This concern has resulted in increasingly stringent noise restrictions for airports, both nationally and internationally. One of the major stretch goals for NASA is to...

Visual acuity (clearness of vision) usually is measured by an eye doctor using an eye chart. It measures the smallest letters that can be reliably identified by the patient at a specified distance. The traditional test requires the patient to look and report which letters they see.

Aircraft noise is a significant problem with both economic and public health implications, especially for communities near airports. As a result, increasingly stringent constraints are being placed on aircraft carriers worldwide to reduce this noise. The current disclosure focuses on airframe noise generated at or...

A paper describes a new technique designed to increase significantly the sensitivity for finding and tracking small, dim, and fast-moving near Earth asteroids (NEAs). The technique relies on a combined use of a novel data processing approach and a new...

Astronauts suffer from poor dexterity of their hands due to the clumsy spacesuit gloves during Extravehicular Activity (EVA) operations, and NASA has had a widely recognized but unmet need for novel human-machine interface technologies to...

A proof-of-concept technique has been developed for measuring and controlling the individual phases of array elements. Electro-optic steering and beam-forming of laser beams is an emerging field with devices such as optical phased arrays that are capable of steering with significantly...

Visual odometry (VO) refers to the estimation of vehicle motion using onboard cameras. A common mode of operation utilizes stereovision to tri angulate a set of image features, track these over time, and infer vehicle motion by computing the apparent point cloud motion with respect to the cameras. It has...

Visual odometry (VO) refers to the estimation of vehicle motion using onboard cameras. A common mode of operation utilizes stereovision to tri angulate a set of image features, track these over time, and infer vehicle motion by computing the apparent point cloud motion with respect to the cameras. It has...

Theoretical analysis has long indicated that feedback improves the error exponent but not the capacity of point-to-point memoryless channels. The analytic and empirical results indicate that at short blocklength regime, practical rate-compatible punctured convolutional (RCPC) codes achieve low latency with the...

The objective of this research was to develop a fundamentally new method for detecting hidden moving targets within noisy and cluttered data-streams using a novel “soliton resonance” effect in nonlinear dynamical systems.

A document discusses the CCD97 from e2v technologies as it is being evaluated at Goddard Space Flight Center’s Detector Characterization Laboratory (DCL) for possible use in ultra-low background noise space astronomy applications, such as Terrestrial Planet Finder Coronagraph...

Direct to Earth return links are limited by the size and power of lander devices. A standard alternative is provided by a two-hops return link: a proximity link (from lander to orbiter relay) and a deep-space link (from orbiter relay to Earth). Although direct to Earth return links are limited...

A report describes the Submillimeter Planetary Atmospheric Chemistry Exploration Sounder (SPACES), a highsensitivity laboratory breadboard for a spectrometer targeted at orbital planetary atmospheric analysis. The frequency range is 520 to 590 GHz, with a target noise temperature...

A Sensor Data Qualification (SDQ) function has been developed that allows the onboard flight computers on NASA’s launch vehicles to determine the validity of sensor data to ensure that critical safety and operational decisions are not based on faulty sensor...

A document discusses sequential probability ratio tests that explicitly allow decision-makers to incorporate false alarm and missed detection risks, and are potentially less sensitive to modeling errors than a procedure that relies solely on a probability of...

A method has been developed to measure the total effective noise power in a GPS receiver, including contributions from the system temperature, the antenna temperature, interference, lossy components, etc. A known level of noise is periodically injected before the...

Free space optical communications links from deep space are projected to fulfill future NASA communication requirements for 2020 and beyond. Accurate laser-beam pointing is required to achieve high data rates at low power levels. For the highest pointing accuracy, a laser beacon transmitted...

Supersonic aircraft generate shock waves that move outward and extend to the ground. As a cone of pressurized air spreads across the landscape along the flight path, it creates a continuous sonic boom along the flight track. Several factors can influence sonic booms: weight, size, and...

At extreme temperatures, cryogenic and over 300 °C, few electronic components are available to support intelligent data transfer over a common, linear combining medium. This innovation allows many sensors to operate on the same wire bus (or on the same airwaves or optical...

Single-slope analog-to-digital converters (ADCs) are particularly useful for on-chip digitization in focal plane arrays (FPAs) because of their inherent monotonicity, relative simplicity, and efficiency for column-parallel...

The purpose of this program was to develop single-photon-sensitive shortwavelength infrared (SWIR) and midwavelength infrared (MWIR) avalanche photodiode (APD) receivers based on linear-mode HgCdTe APDs, for application by NASA in light detection and ranging (lidar) sensors. Linear-mode...

Investigation of sonic boom has been one of the major areas of study in aeronautics due to the benefits a low-boom aircraft has in both civilian and military applications. Current Federal Aviation Administration regulations prohibit supersonic flight over land due to...

Packaging of MMIC LNA (monolithic microwave integrated circuit low-noise amplifier) chips at frequencies over 200 GHz has always been problematic due to the high loss in the transition between the MMIC chip and the waveguide medium in which the chip will typically be used. In...