Analytic Method for Estimating Aircraft Fix Displacement From Gyroscope’s Allan-Deviation Parameters

Method for estimating scene parameters from color histograms

One of the key tools in applying physics-based models to machine vision has been the analysis of color histograms. In the mid-1980’s it was recognized that the color histogram for a single inhomogeneous surface with highlights will have a planar distribution in color space. I t has since been shown that the colors do not fall randomly in a plane but form clusters a t specific points. Physics-ba...

A new method for estimating joint parameters from motion data.

Joint centers and axes of rotation (joint parameters) are central to all branches of movement analysis. In gait analysis, the standard protocol used to determine hip and knee joint parameters is prone to errors arising from palpation, anthropometric regression equations, and misplaced alignment devices. Several alternative methods have been proposed, but to date none have been shown to be accur...

Method for Estimating Scan Parameters from Tomographic Data

Fast Computation of Time Deviation and Modified Allan Deviation for Telecommunications Clock Stability Characterization

Time and frequency characterization of precision clocks and oscillators is an important task in the maintenance of time and frequency standards. Recently, time domain signal characterization of clocks is generally preferred and several pedormance measures of clocks and oscillators are defined in ITU-T Recommendation G.810. Among these measures, Maximum Time Interval Error (MTIE), Time Deviation...

Validation of Methodology for Estimating Aircraft Unsteady Aerodynamic Parameters from Dynamic Wind Tunnel Tests

A basic problem in flight dynamics is the mathematical formulation of the aerodynamic model for aircraft. This study is part of an ongoing effort at NASA Langley to develop a more general formulation of the aerodynamic model for aircraft that includes nonlinear unsteady aerodynamics and to develop appropriate test techniques that facilitate identification of these models. A methodology for mode...