Measurements of the statistical properties of atmospheric turbulence at altitudes below 1000 feet

Abstract

Measured statistical properties of the three components of turbulence are presented for research flights at four altitudes below 1000 feet over flat terrain and two altitudes below 1000 feet over hilly terrain. The measured power spectral density distributions were closely approximated by the von Karman spectral shape. The derived scales of the three components were all about the same, being approximately proportional to height over the flat terrain. The derived scales at the higher altitudes appeared to be related to the terrain a considerable di stance up-wind from the track along which the measurements were made. A comparison of the present results with those from the U. S. Air Force sponsored LO-LOCA T measurements showed good general agreement with the exception that the intensities at the higher wind velocities were significantly greater than those of the LO-LOCAT studies.