Length measurements of mid‐latitude scintillation irregularities

The lengths of irregularities which produce 150‐MHz amplitude scintillations have been measured at 43°N, 81°W (geographic) using arrays of receivers with large spacings. The average length (major axis radius) of the irregularities was 6.1 km. This is much shorter than expected and implies that the measurements are of “young” irregularities, less than 1 minute old. These irregularities appear to be a large, 25–50% perturbation of the background density.