Tracking of Nonstationary Noise Based on Data-Driven Recursive Noise Power Estimation

This paper considers estimation of the noise spectral variance from speech signals contaminated by highly nonstationary noise sources. The method can accurately track fast changes in noise power level (up to about 10 dB/s). In each time frame, for each frequency bin, the noise variance estimate is updated recursively with the minimum mean-square...

On the Estimation of Complex Speech DFT Coefficients Without Assuming Independent Real and Imaginary Parts

This letter considers the estimation of speech signals contaminated by additive noise in the discrete Fourier transform (DFT) domain. Existing complex-DFT estimators assume independency of the real and imaginary parts of the speech DFT coefficients, although this is not in line with measurements. In this letter, we derive some general results on...

LPC interpolation by approximation of the sample autocorrelation function

Bias propagation in the autocorrelation method of linear prediction

Autoregressive modeling for speech coding: Estimation, interpolation and quantization

Flight simulator evaluation of advanced MLS procedures

The flight simulator study described in this report concerns an evaluation of manually flown, flight director aided, curved MLS approach and departure procedures with a simulated wide-body transport aircraft. Four curved approach paths and two departure procedures have been evaluated, where these procedures were determined to be beneficial from...

Flight simulator evaluation of the flyability of curved MLS approaches with wide-body aircraft

The flight simulator study described In this report concerns an evaluation of flight director flown curved MLS approach paths with a simulated wide-body transport aircraft. Four curved approach paths, consisting of two straight segments and one 90 degrees circular segment with different straight final segment lengths, have been investigated....

Flight simulator investigation on the approach path parameters for MLS curved approaches

The present flight simulator study has been addressed to the evaluation of the approach path parameters for curved approach paths. A number of seven oblique approach paths has been investigated, varying in both straight final length and oblique angle. The investigation was carried out for various operating minima (decision height, runway visual...

Investigation on MLS approach path interception and transition techniques: part II: flight simulator investigation

Due to the wide coverage volume of MLS, in both azimuth and elevation, the system enables the introduction of new approach and terminal area procedures. For several years the NLR has been investigating the potential of MLS with respect to the execution of non-straight-in approaches. In an earlier theoretical study four MLS-guided interception...

Investigation on MLS approach path interception and transition techniques: part I: fast-time computer simulations

MLS provides the possibility to define non-straight-in approach paths and to use more advanced interception procedures. From an ATC point-of-view it became necessary to structure this capability as a prerequisite in order to make a realistic use of the potential capabilities of MLS. Four different MLS approach path interception procedures were...

A method for applying linear optimal control theory to the design of a regulator for a flexible- aircraft

This report deals with determining a hypothetic control system which provides improved rigid body and structural mode damping of a flexible aircraft in order to improve the riding qualities and to minimize the wing bending moment during flights in turbulence. The equations of motion used in the computations are related to a high' performance...

A simulation investigation on the feasibility of curved approaches under MLS guidance. Revised edition

The use of panel methods with a view to problems in aircraft dynamics

A survey is given of the basic principles of the panel methods. The most frequently used methods, steady as well as unsteady, are described in some detail. Recent developments aiming at improvönent and extension of the range of applicability are reviewed. The use of panel methods for the determination of stability derivatives is discussed....

Investigation on a passenger ride-comfort improvement system with limited control surface actuator performance for a flexible aircraft

For the low wing-loading aircraft, considered in this investigation, vertical acceleration appeared to be an important factor concerning passenger comfort. To reduce vertical motions, a ride-comfort improvement system was introduced. Determination of parameters of the system, like gains and allowable performance limitations, required analog...

Preliminary investigation on the ride-comfort improvement of a low wing-loading transport, including a limited comfort criteria study

A limited investigation on the possihility of improving the passenger ride comfort of a low wing-loading transport has heen descrihed in the present report. A literature study on comfort criteria, included in this report, did show that passengers attach much importance to vertical and lateral motion. It appeared that for the aircraft concerned...

Comparison of Fokker F28 wind tunnel and flight data; a summary

For an accurate prediction of aircraft characteristics the wind tunnel tests are of paramount impoitance. Therefore the significance of the test results and available extrapolation techniques have to be investigated as thoroughly as possible. For this reason a program for comparing wind tunnel and flight test data of the Fokker F-28 was set up,...