Analysis of Single and Multiple Wavelength Radar Systems for Estimating Slant Path Attenuation Through Rain and Cloud at Frequencies Greater than 10 GHz.

摘要

The feasibility of using various types of radars including dual wavelength configurations for arriving at slant path attenuations through rain and cloud at frequencies up to 100 GHz has been analyzed. Optimum performance parameters of systems which best perform these functions are established. The configurations examined include single S-band (f = 3 GHz) and K sub u-band (f = 15.7 GHz) systems as well as dual wavelength systems operating at K sub a-S (35-3 GHz) and K sub u-S (15.7-3 GHz) bands. The following conclusions have been arrived at from the analysis of the above systems: (1) Of the various systems examined, the most straightforward is an S-Band system monitoring the path reflectivity profiles. (2) The use of a single attenuation wavelength radar (e.g., one operating at 15.7 GHz) for measuring rain path attenuation leads to unacceptably high errors and should be avoided. (3) A radar system operating at 15.7 GHz is suitable for estimating cloud liquid water content from which cloud path attenuation may be determined at frequencies above 10 GHz. (4) A dual wavelength system involving K sub a and S-band (35-3 GHz) radar system is feasible for establishing drop size distributions aloft from which appropriate empirical relations at higher frequencies may be generated. (5) A K sub u-S band (15.7-3 GHz) dual wavelength system may give rise to unacceptably large errors and its use should be avoided. (Author)