Isadore Katz

Tropopause Detected by Radar

The tropopause has been detected by ultrasensitive, narrow-beam, microwave (10.7-centimeter) and ultrahigh-frequency (71.5-cm) radars. Its reflectivity is consistent with that expected theoretically for a refractively turbulent medium. Indications are that the layer is also mechanically turbulent, and that electromagnetic scatter techniques may be used to detect high-altitude clear-air turbulence.

Clear-air turbulence - Simultaneous observations by radar and aircraft.

Ultrasensitive radars and uninstrumented jet aircraft in concert have probed regions of the clear atmosphere in search of clear-air turbulence. All sources of clear-air radar echoes above 6 kilometers that were probed simultaneously by the aircraft were found to be turbulent.

A Momentum Disdrometer for Measuring Raindrop Size from Aircraft

There exists a need to measure raindrop distributions in storms being investigated by radar. A new airborne instrument for such measurements has been developed which measures simultaneously the dro...

Probing the Optically Clear Atmosphere with Radar

The recent use of high-power radars for lower atmosphere research has shown these radars are capable of yielding information not possible heretofore. Most microwave radars were useful in studying processes associated with precipitation and, to some extent, clouds. With the advent of radars of the class of those at Wallops Island (Katz, 1966) whose minimum detectible signals were perhaps 30 db better than radars in use as weather radars, it became possible to view the optically clear atmosphere in motion, at least under certain conditions. This review will be limited to a discussion of such phenomena visible with radars within the lower, say, 20,000 feet of the earth’s surface. We shall also restrict our discussion to those radar echoes which are of atmospheric origin and omit any mention of the large and interesting class of dot echoes, i.e. echoes from birds or insects. In the following we shall discuss layer type echoes, echoes from convective cells and instrumented aircraft flights into echo regions to find a relationship between echo signal strength and statistical properties of the atmosphere.

Radar Meteorology at Radiation Laboratory, MIT, 1941 to 1947

The Radiation Laboratory of the Massachusetts Institute of Technology (MIT) was primarily responsible for the development of radar during World War II. The Laboratory was divided into many specialized groups; Group 42, a subdivision of the Laboratory, was assigned the field of propagation of electromagnetic (EM) waves, especially in the centimeter wavelength region (Kerr, 1951).