Heliostat beam characterization system-calibration technique

Conference · Mon Jan 01 00:00:00 EST 1979

OSTI ID:6079363

Phipps, G S

The Beam Characterization System (BCS) used at the Central Receiver Test Facility digitizes the output signal from a standard 525-line video camera to obtain raw data for measurements of solar heliostat images. A rapid data rate and relative availability of off-the-shelf equipment favor the use of a video camera system, but the problem of an accurate absolute radiometric calibration must be addressed. Absolute irradiance values are obtained from a calibrated pyrheliometer included on the target screen. The video camera must measure relative irradiance values of areas of identical spectral composition, greatly simplifying the calibration procedure. Not only must the camera and digitizer linearity be measured, but imaging screen reflectance, lens and filter effects, and camera spatial sensitivity must also be considered for accurate results. Measurements are made over a two dimensional spatial array of N screen locations. Calibration corrections must be applied to the data from the N locations to obtain a single calibrated irradiance data matrix. Methods of obtaining these corrections are discussed and measured results are presented to support the various assumptions.

• Research Organization: Sandia Labs., Albuquerque, NM (USA)
• DOE Contract Number: EY-76-C-04-0789
• OSTI ID: 6079363
• Report Number(s): SAND-79-1532C; CONF-791005-2
• Resource Relation: Conference: ISA national conference, Chicago, IL, USA, 22 Oct 1979
• Country of Publication: United States
• Language: English

Related Subjects

14 SOLAR ENERGY
HELIOSTATS
BEAM OPTICS
CALIBRATION
CENTRAL RECEIVERS
CORRECTIONS
IMAGES
PYRHELIOMETERS
RADIOMETERS
SOLAR FLUX
TEST FACILITIES
VIDICONS
CAMERA TUBES
IMAGE TUBES
MEASURING INSTRUMENTS
RADIATION DETECTORS
SOLAR RECEIVERS
TELESCOPES
140702* - Solar Thermal Power Systems- Central Receiver