Hemispherical Reflectance Measurement Field Instrument Design.
Abstract
This Phase I small business innovation research (SBIR) final report describes the design of a man-portable, bidirectional reflectometer field instrument. The instrument can irradiate any sample surface with several spectral bands of radiation (ultraviolet, mid-infrared, and long-infrared) and measure the reflectance. The data from this reflectance measurement can characterize the bidirectional reflectance distribution function (BRDF) of the sample. The source illumination angle is varied, and a complete BRDF characterization can be obtained for each of a possible 90 illumination angles. The instrument is automatic and has self-test and self-calibrate features. The computer that controls the test gathers the digital data that can be transferred over a serial (RS232) or parallel (IEEE 488) data link. The vacuum sample stage is designed to securely hold foliage specimens in place without removal from the plant. This stage can be moved aside for other samples (i.e., rocks, limbs, ground, etc.). The low profile of the device allows the unit to rest directly on the sample to be tested permitting tests of road surfaces, grass fields, etc. This instrument has a sensor unit and a control/power unit. The unit can be powered from an automobile cigarette lighter or a 12-V battery belt.
Document Details
- Document Type
- Technical Report
- Publication Date
- Jul 15, 1991
- Accession Number
- ADA289671
Entities
People
- Till W. Liepmann