HelioPoint – A Fast Airborne Calibration Method for Heliostat Fields

The pointing calibration of a newly built heliostat field can take up to several years. The state-of-the-art method typically used is accurate but slow. A faster method could reduce the commissioning time and therefore increase the viability of a solar tower plant significantly. In this work, we present HelioPoint, a fast airborne heliostat calibration technique, and demonstrate its accuracy to be better than 0.3 mrad. The measurement is performed using a light-emitting diode (LED) and a camera fitted to a drone. The only infrastructure required is the roughly pre-aligned heliostats themselves. The method is independent of the sun position and can be performed at any time for arbitrary calibration points.