A Laboratory Goniometer System for Measuring Reflectance and Emittance Anisotropy

Sensors

Peter P. J. Roosjen¹  Jan G. P. W. Clevers¹  Harm M. Bartholomeus¹  Michael E. Schaepman⁴  Gabriela Schaepman-Strub²  Henk Jalink³  Rob van der Schoor³ 

[1] Laboratory of Geo-Information Science and Remote Sensing, Wageningen University, P.O. Box 47, 6700 AA Wageningen, The Netherlands; E-Mails:;Institute of Evolutionary Biology and Environmental Studies, University of Zurich, Winterthurerstrasse 190, CH-8057 Zurich, Switzerland; E-Mail:;Wageningen UR Greenhouse Horticulture, P.O. Box 644, 6700 AP Wageningen, The Netherlands; E-Mails:;Remote Sensing Laboratories, Department of Geography, University of Zurich, Winterthurerstrasse 190, CH-8057 Zurich, Switzerland; E-Mail:

关键词: reflectance anisotropy;    BRDF;    emittance anisotropy;    laboratory goniometer;    biophysical parameter retrieval;   

DOI  :  10.3390/s121217358

来源: mdpi

【 摘 要 】

In this paper, a laboratory goniometer system for performing multi-angular measurements under controlled illumination conditions is described. A commercially available robotic arm enables the acquisition of a large number of measurements over the full hemisphere within a short time span making it much faster than other goniometers. In addition, the presented set-up enables assessment of anisotropic reflectance and emittance behaviour of soils, leaves and small canopies. Mounting a spectrometer enables acquisition of either hemispherical measurements or measurements in the horizontal plane. Mounting a thermal camera allows directional observations of the thermal emittance. This paper also presents three showcases of these different measurement set-ups in order to illustrate its possibilities. Finally, suggestions for applying this instrument and for future research directions are given, including linking the measured reflectance anisotropy with physically-based anisotropy models on the one hand and combining them with field goniometry measurements for joint analysis with remote sensing data on the other hand. The speed and flexibility of the system offer a large added value to the existing pool of laboratory goniometers.

【 授权许可】

CC BY   
© 2012 by the authors; licensee MDPI, Basel, Switzerland