Estimation of Uncertainty in Automated Heliostat Alignment

Engineers seek to reduce the cost of solar-thermal central tower systems by reducing the cost of the heliostat field. Lower-cost heliostats can be achieved by accepting lower precision in manufacture and installation. Automated alignment methods can then be used to correct pointing errors due to misalignments after the heliostat is installed, to obtain and maintain the required pointing accuracy. The method under consideration here is the beam-target method, in which the location of the reflected spot on a target is measured repeatedly, and linear regression is applied to estimate various geometrically-based physical misalignment parameters to facilitate pointing error correction.