Lab developed software, with source code available under license agreements:
The NIO (Non-Intrusive Optical) method is a UAS surveying method for large heliostat fields. Commercial UAS fly pre-generated flight paths to capture the reflection of a CSP plant’s central tower moving across each heliostat. These images are processed using advanced computer vision algorithms to assess the surface shape quality of each heliostat. NIO measures the pointing, facet canting, and surface slope of measured heliostats. NREL is currently working on automating this tool for large-scale processing.
- A non-intrusive optical (NIO) approach to characterize heliostats in utility-scale power tower plants: Methodology and in-situ validation
- A non-intrusive optical approach to characterize heliostats in utility-scale power tower plants: Flight path generation/optimization of unmanned aerial systems
ReTNA (Reflected Target Non-intrusive Assessment) is a lightweight, high-precision method to measure heliostats in the laboratory, on the manufacturing assembly line, and in the field. This system measures the deflection of reflected computer vision targets to characterize heliostat surface shape. ReTNA is comparable and complimentary system to traditional fringe deflectometry. By using a printed target and careful calibration of the system with photogrammetry, the tool can stitch together many images to measure a large heliostat with a small lightweight target.
- Improvements in Optical Surface Measurement Using Reflected Computer Vision Targets
- Improvements in Reflected Target Non-intrusive Assessment (ReTNA)
- A New Reflected Target Optical Assessment System: Stage 1 Development Results