July - September 1996, Volume 17, Number 3


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Research and Development Updates

Basic Research

Investigation of Signal Characteristics Using the Continuous Wavelet Transform
J. Sadowsky

Applied Research

Development of Optical Filters Based on Photorefractive Materials
P. R. Schuster, J. A. Miragliotta, M. E. Thomas, and D. M. Rust

Astronomical Refraction
M. E. Thomas and R. I. Joseph


Shared Aperture Technology Development
T. A. Axness, R. V. Coffman, B. A. Kopp, and K. W. O'Haver

Information Technology

Collaborative Virtual Prototyping
J. S. Lombardo, E. Mihalak, and S. R. Osborne

Systems Engineering

The Emerging Joint System of Systems: A Systems Engineering Challenge and Opportunity for APL
W. H. J. Manthorpe, Jr.

System Integration

Integration of the Evolved Seasparrow Missile into Ships of the NATO Seasparrow Consortium Navies
S. A. Hyer, J. J. Johnston, and C. L. Roe

Book Review

A Comprehensive Look at Flame Research
R. G. Gann

APL Awards

Awards for Publications and Research and Development
L. L. Maier-Tyler

In Memoriam

Chih Kung Jen - A Remembrance
W. G. Berl


Publications, Presentations, and Colloquia

The cover: What are seemingly rock columns in a cavern are actually features of a time versus scale representation of a transient signal. The image was generated with a continuous wavelet transform using a Morlet wavelet (see the article by J. Sadowsky in this issue). The transform produces a complex image (i.e., each pixel has both intensity amplitude and phase). Phase is represented as saturation by black dots, and amplitude is represented as grayscale, where darker gray corresponds to higher amplitude. The horizontal direction in the image is time, and the vertical direction is scale; the smaller scale representing finer detail is at the top. The periodicity of the columns indicates frequency at the scale and is due to the phase of the complex image. (Cover illustration by Kenneth R. Moscati.)

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Editorial Board
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© 1996 by The Johns Hopkins University Applied Physics Laboratory

The Electronic Version of The Johns Hopkins APL Technical Digest was created by the Technical Publications Group (TIR).