Abstract:
In a water content evaluation method, when water content of a part of a plant is evaluated, a white reference substrate (background material) is disposed so as to cover a back surface of a leaf of plant. A first beam source radiates a near infrared beam (reference beam) with a wavelength of 905 nm that has a characteristic of tending not to be absorbed in water toward leaf. A second beam source radiates a near infrared beam (measuring beam) with a wavelength of 1550 nm that has a characteristic of tending to be absorbed in water toward the leaf. Threshold level setter/water content index detector calculates a water content index of one leaf that is total sum Σ Ln (I905/I1550) of the reflection intensity rate at all irradiation positions of the leaf based on a reflection light of a reference beam and a reflection light of a measuring beam that are reflected on all irradiation positions of the leaf.
Abstract:
A method and apparatus for measuring light reflections of an object, comprising a light-source illumination-observation assembly, the assembly comprising: (A) an illumination unit comprising an illumination light source and illumination aperture stop being arranged to provide a confined luminous field, an illumination field stop ( 307 ) adapted to provide an illumination beam ( 305 ) of light from said confined luminous field, an collimating optical element ( 309 ) adapted to collimate said illumination beam and to provide an illumination field ( 313 ) on an object; (B) an observation unit comprising: at least one observation field stop adapted to provide an observation beam ( 306 ) comprising a ray boundary, at least one focusing optical element ( 309 ) adapted to focus said observation beam, an observation light receiver; and (C) at least one common optical element ( 309 ) arranged so that said illumination beam and said observation beam form an overlap therein; and (D) a unit separation stop ( 310 ) adapted to stop light from said illumination unit in reaching said observation light receiver of said observation unit; wherein said at least one observation field stops ( 308, 310, 311 ) comprises at least one limiting field stop ( 310 ) adapted to limit said ray boundary of said observation beam and to maintain said overlap of said illumination beam and said observation beam; a diffuser light-source assembly; and use thereof.
Abstract:
A method and apparatus for estimating reflectance parameters and a position of the light source(s) of specular reflections of a scene include RGB sequence analysis with measured geometry in order to estimate specular reflectance parameters of an observed 3D scene. Embodiments include pixel-based image registration from which profiles of 3D scene points image intensities over the sequence are estimated. Profiles are attached to a 3D point and to the set of pixels that display its intensity in the registered sequence. Subsequently, distinction is made between variable profiles that reveal specular effects and constant profiles that show diffuse reflections only. Then, for each variable profile diffuse reflectance is estimated and subtracted from the intensity profile to deduce the specular profile and the specular parameters are estimated for each observed 3D point. Then, the location of at least one light source responsible for the specular effects is estimated. Optionally, the parameters can be iteratively refined to determine color information and specular reflectance parameters.
Abstract:
Systems, methods and apparatus are provided for monitoring soil properties including soil moisture, soil electrical conductivity and soil temperature. Embodiments include a soil reflectivity sensor and/or a soil temperature sensor for measuring moisture and temperature.
Abstract:
A wavelength correction function provides corrected reflectance values from actual reflectance values taken in a reflectance-base instrument. The correction is provided as a function of measured reflectance values and a predefined set of high resolution reflectance values established for the reflectance-based instrument implementing the wavelength correction function.
Abstract:
A quality evaluation method includes an acquisition step of acquiring spectral data related to transmitted light or diffusely reflected light from a cell mass by irradiating the cell mass with measurement light including near-infrared light, and an evaluation step of evaluating quality of the cell mass, based on the spectral data of the cell mass acquired in the acquisition step.
Abstract:
Apparatus for analysing a surface which, in use, is subject to drag, the apparatus comprising, a light source for generating light of at least one predetermined wavelength, a light source holder for holding and positioning the light source so as to direct it at the surface, a light detector for detecting reflected light from the surface and generating a signal in response thereto, a light detector holder for holding the light detector and positioning it so as to detect the reflected light, and a connector for connecting the light detector to a microprocessor to analyse the signal. Also disclosed is a method of analysing a surface which, in use, is subject to drag.