Haraka,
Ex Tartan Shadow was conducted at Kinloss in 1992. Nimrods were parked adjacent to seemingly abstract sharp edged shapes painted onto the toned down concrete. Some shapes were lighter 'concrete' colour, others were black.
We got the local Buccaneer guys to come over at various heights and speeds (without telling them what to expect) to see what they made of them.
The general consensus was that the 'shapes' were easy to tell apart from the real Nimrods, which was no great surprise. However, on their first encounter with the shapes they were momentarily distracted, wondering what they were. The scientists who came up with the shapes were delighted at this, as that apparently was what they had been hoping to achieve.
and then, just like everything else ... it was all forgotten ... and someone will re-invent it in another decade or so ...