Observations of insects and birds with a polarimetric radar

The authors present observations of biological scatterers with a polarimetric weather radar. The radar has a pencil beam, a high power, and a wavelength of 10 cm. It transmits horizontally and vertically polarized waves alternately. The available polarimetric variables are differential reflectivity, differential phase, and correlation coefficient between orthogonally polarized returns. Two types of biological scatterers, insects and birds, are contrasted. Observed polarimetric signatures of these are compared and explained with a simple scattering model. Finally, the authors discuss the implications of recognizing the biological scatterers' type and the size of birds.