I was looking at some photos the other day and one showed four separate structures that look like skateboard ramps turned up on the fat end. The tag said it was part of an abandoned radar installation. If so, what was their purpose?
That was most likely a low frequency radar. You must remember- the higher the frequency of the carrier wave, the shorter the wavelength, and the smaller the cross-section of the antenna. The modulation doesn't matter. The carrier wave freq is the only determinant.