Defence Research Agency

About: Defence Research Agency is a based out in . It is known for research contribution in the topics: Synthetic aperture radar & Radar. The organization has 1211 authors who have published 1109 publications receiving 31542 citations.

Estimating the Inverse Autocorrelation Function from Outlier Contaminated Data

Abstract: We show how a number of commonly used estimates of the inverse autocorrelation function can be modified to deal with outlier contaminated data. The robust analogues of the orthogonal and interpolation based techniques appear to be new, and provide an alternative to the robust autoregressive approach. We examine the performance of these techniques in a large scale numerical experiment. This shows significant improvements in performance in outlier contaminated data when robust techniques are used. While there was no uniformly best robust technique, our experiments support the use of the autoregressive approach to avoid catastrophic reductions in performance, and robust interpolation for short series corrupted by few outliers.

Integrated Flying Helmets

Abstract: The addition of vision enhancement, display and control functions to aviator's headgear is operationally attractive. Fast jets and helicopters currently under development call for headgear with a combination of these novel facilities.This paper reviews the recent history of such helmet systems, which demonstrate admirably the inventiveness of the design teams. However, there are attendant perceptual and operational concerns and the addition of extra components invariably compromises basic ergonomic qualities.It is suggested that a new design philosophy, which emphasizes functional integration rather than the incorporation of compatible sub-systems, has become essential. This will be assisted significantly when key optical and electro-optical technologies become mature.