Fraunhofer-gesellschaft Zur Foerderung Der Angewandten Forschung E.v.

Peter Schoettl

Peter Nitz

Gregor Bern

Anna Heimsath

Thomas Schmidt

De Wet Van Rooyen

Moritz Bitterling

A method for the optical determination of an intensity distribution, includes a) producing a spatially inhomogeneous radiation field of electromagnetic radiation; b) producing a first relative movement between a position-resolving image sensor and the radiation source with the radiation field moving along a first measurement path over a sensor field of the image sensor, so it is scanned by a first measurement path region of the radiation field; c) recording a first image set with position-resolved images of the radiation field during the first movement; d) producing a similar second relative movement between the image sensor and the radiation source, along a second measurement path not parallel to the first movement path; d) similarly recording a second image set during the second relative movement; e) evaluating the position-resolved images of the first and second image sets at least at points of intersection, the locations of which are defined by evaluation lines; and f) determining a relative intensity distribution based on points of intersection of the evaluation lines to characterize the image sensor and/or the radiation field.

Method for the optical determination of an intensity distribution

The invention relates to a calibration method for a group of reflectors for concentrating solar radiation onto a radiation receiver, having the following steps: A) aligning the reflectors in order to at least partly expose a calibration surface to solar radiation reflected by the reflectors; B) modifying the intensity distribution of the radiation incident on the calibration surface by carrying out a pattern of movements by each reflector of the group, wherein at least one specified parameter for the pattern of movements of each reflector differs from the parameters of the other reflectors, said parameter being selected from the group: &#x2014;movement frequency,&#x2014;movement amplitude,&#x2014;movement phase angle, and&#x2014;trajectory of the solar radiation, reflected by the reflector, within the calibration surface; C) recording rows of pixels for a plurality of differently located location points of the calibration surface by at least one camera, each row of pixel having at least five temporally offset pixel recordings; D) ascertaining a spectrum for each row of pixels by transforming the row of pixels into the frequency domain; E) assigning a subset of spectra to the reflectors on the basis of the movement pattern parameter of the reflector; and F) determining at least one reflection target position for each reflector at least on the basis of the subset of spectra assigned to the reflector. The invention additionally relates to a calibration device for a group of reflectors for concentrating solar radiation onto a radiation receiver.

Calibration method and calibration device for a group of reflectors for concentrating solar radiation onto a radiation receiver

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Freiburg, Germany

Peter Schoettl