University of Surrey

Test tubes in the lab Research in the ATI Dance Research

Doppler Signatures From Canonical Rotating Targets.

Christensen, John Kenneth. (2004) Doppler Signatures From Canonical Rotating Targets. Doctoral thesis, University of Surrey (United Kingdom)..

[img]
Preview
Text
11010057.pdf
Available under License Creative Commons Attribution Non-commercial Share Alike.

Download (22MB) | Preview

Abstract

This thesis adopts an empirical approach to explore the issues associated with the dynamic radar signatures of spinning electrically large dielectric and metallic canonical targets; and especially rotating cylinders. A survey of historical and contemporary open source literature indicates a lack of material in this subject area. A focussed field of investigation is therefore formulated and followed to address this 'short fall'. New coherent phase coded pulse Doppler radar hardware is described and used to gather new and original data. Novel results are presented for nominally axi-symmetric spinning broadside plane wave illuminated electrically rough and electrically smooth cylinders. These results contain strong Doppler shifted components of the rotation frequency. An asymmetric and discrete line spectrum is seen that can be characterised by AM and PM components. A new 'vector in a box' approach is used to understand concomitant ambiguities associated with the representation of these types of modulation phenomena. The concept of 'complex Doppler' is introduced and a non-typical application of the dark field illumination technique is used to decompose the target signature to identify direct (first order) and delayed (second order) Doppler mechanisms. Other results for three classes of geometry of motion provide deeper insights into dynamic target phenomenological behaviour. It is suggested that these results could lead to improved methods for the aero-ballistic analysis of projectile angular motion. The totality of the results presented in this thesis represent a significant addition to the open source data pool and have advanced the state of the art in the understanding of dynamic signatures from rotating cylinders. The results are shown to have relevance to a variety of defence and industrial scientific applications and will therefore be of interest to a wide audience. Finally a new Doppler-surface mapping (D-map) methodology is given that provides a mechanism to discriminate between targets with differing electrical (material) properties or surface roughness characteristics. The D-map technique is simple to apply and exploits the unique spectral features associated with the Doppler line spectra from rotating electrically large canonical targets such as cylinders. The D-map technique is therefore shown to be a useful tool and is hence a valuable contribution to the state of the art in the area.

Item Type: Thesis (Doctoral)
Divisions : Theses
Authors : Christensen, John Kenneth.
Date : 2004
Additional Information : Thesis (Ph.D.)--University of Surrey (United Kingdom), 2004.
Depositing User : EPrints Services
Date Deposited : 30 Apr 2019 08:07
Last Modified : 20 Aug 2019 15:32
URI: http://epubs.surrey.ac.uk/id/eprint/851324

Actions (login required)

View Item View Item

Downloads

Downloads per month over past year


Information about this web site

© The University of Surrey, Guildford, Surrey, GU2 7XH, United Kingdom.
+44 (0)1483 300800