Mystery structure

For the past 2 years I have been walking past this strange metal structure in the middle of a patch of public grass. Until recently it was mostly covered in plastic sheeting and I always wondered what it was. Now it has at last been revealed but the mystery continues. It might be measuring something as the blue lights in the centre are constantly moving up and down. But what? noise? the sea? light? There is no information on what it is, why it's there or who put it there. Weird.