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Titre du document / Document title

Coherent backscatter : Measurement of the retroreflective BRDF peak exhibited by several surfaces relevant to ladar applications

Auteur(s) / Author(s)

PAPETTI Thomas J. (1) ; WALKER William E. (1) ; KEFFER Charles E. (1) ; JOHNSON Billy E. (2) ;

Affiliation(s) du ou des auteurs / Author(s) Affiliation(s)

(1) EDO-CAS, Inc., P.O. Box 11190, Huntsville, AL 35814, ETATS-UNIS
(2) U.S. Army Space and Missile Defense Command, P.O. Box 1500, Huntsville, AL 35807, ETATS-UNIS

Résumé / Abstract

The sharp retroreflective peak that is commonly exhibited in the bidirectional reflectivity distribution function of diffuse surfaces was investigated for several materials relevant to ladar applications. The accurate prediction of target cross-sections requires target surface BRDF measurements in the vicinity of this peak. Measurements were made using the beamsplitter-based scatterometer at the U.S. Army's Advanced Measurements Optical Range (AMOR) at Redstone Arsenal, Alabama. Co-polarized and cross-polarized BRDF values at 532 nm and 1064 nm were obtained as the bistatic angle was varied for several degrees about, and including, the monostatic point with a resolution of better than 2 mrad. Measurements covered a wide range of incidence angles. Materials measured included polyurethane coated nylons (PCNs), Spectralon, a silica phenolic, and various paints. For the co-polarized case, a retroreflective peak was found to be nearly ubiquitous for high albedo materials, with relative heights as great as 1.7 times the region surrounding the peak and half-widths between 0.11° and 1.3°. The shape of the observed peaks very closely matched coherent backscattering theory, though the phenomena observed could not be positively attributed to coherent backscattering or shadow hiding alone. Several data features were noted that may be of relevance to modelers of these phenomena, including the fact that the widths of the peaks were approximately the same for 532 nm as for 1064nm and an observation that at large incidence angles, the width of the peak usually broadened in the in-plane bistatic direction.

Revue / Journal Title

Proceedings of SPIE, the International Society for Optical Engineering    ISSN  0277-786X   CODEN PSISDG 

Source / Source

Congrès
Polarization science and remote sensing III :   ( 29-30 August 2007, San Diego, California, USA )
Polarization science and remote sensing, San Diego CA , ETATS-UNIS (2007)
2007  , vol. 6682, pp. 66820E.1-66820E.13[Note(s) : various pagings, ] (14 ref.) ISBN 978-0-8194-6830-7 ; 0-8194-6830-4 ;  Illustration : Illustration ;

Langue / Language

Anglais

Editeur / Publisher

Society of Photo-Optical Instrumentation Engineers, Bellingham, WA, ETATS-UNIS  (1981) (Revue)
SPIE, Bellingham, Wash., ETATS-UNIS  (2007) (Monographie)

Mots-clés anglais / English Keywords

Albedo

;

Paints

;

Polyurethanes

;

Military application

;

Silica

;

Cross polarization

;

Optical polarization

;

Reflectivity

;

Visible radiation

;

Incidence angle

;

Measuring methods

;

Beam separators

;

Backscattering

;

Mots-clés français / French Keywords

8920D

;

4279F

;

4225J

;

0130C

;

Albédo

;

Peinture

;

Uréthanne polymère

;

Application militaire

;

Silice

;

Polarisation croisée

;

Polarisation optique

;

Facteur réflexion

;

Rayonnement visible

;

Angle incidence

;

Méthode mesure

;

Séparateur faisceau

;

Rétrodiffusion

;

Mots-clés espagnols / Spanish Keywords

Aplicación militar

;

Polarización cruzada

;

Localisation / Location

INIST-CNRS, Cote INIST : 21760, 35400017285025.0120

Nº notice refdoc (ud4) : 20649919



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