The heliostat array in the above picture was brought to my attention by the users of this site’s forums, so credit goes to iamtawon and samd for finding it.
The system works by using a CMOS camera to examine the reflected light and determine how the heliostats must adjust themselves in order to reflect the sun’s light at the target.
Don’t take my word for it though. You can read all about it yourself in the pdf at this link. Its contents are the brainchild of Joel Thomas Masters who used it as part of his work towards a degree for Master of Science in Mechanical Engineering at California Polytechnic State University.
The document is quite extensive. At the end of it, you’ll even find the code used for controlling the heliostats. It’s definitely worth a look.