Measurements of cross-correlation between spaced receivers from the Virginia Tech OLYMPUS experiment

The Virginian Tech experiment includes 12-, 20-, and 30-GHz beacon receivers and colocated 20-GHz and 30-GHz small-scale diversity terminals to provide data in which the effects of frequency diversity are combined with the effects of spatial diversity. The results obtained with this array of terminals are useful in studying the structure of small-scale turbulence and also in determining optimal diversity configurations. The effects of spatial diversity are studied, through a cross-correlation analysis. The median value of the correlation coefficient is plotted as a function of vertical spacing and the total spacing between the beams of each pair of terminals. As the spacing (total or vertical) increases, the median cross-correlation coefficient decreases fairly rapidly, and then reaches a region of slower variations where the median correlation is nearly constant, with values that may be negative. As the spacing is further increased the median correlation converges to 0.<>