| Summary: | The purpose of this thesis has been to create tools for radar performance estimation in true operational environments and to evaluate the feasibility of millimeter wave band for radar applications. Radar wave propagation and backscattering was studied in different environments using real radar data obtained from field measurement campaigns. Measurement results of radar clutter in typical illumination geometries encountered using a ground-based radar are presented for Ka- and V-band. The low grazing angle (<5°) clutter backscattering measurements as well as measurements at perpendicular incidence presented in this work are completely new results, for which comparisons can not be found in open literature. For example, the snow covered ground backscattering coefficient at V-band was found to be on average 12 dB larger than at Ka-band. Additionally, new volumetric backscattering coefficients of rain and snow at Ka-band are given. Also new spectral dependency values for vegetation clutter spectrum at Ka-band are proposed. The cross-over level from Gaussian low-frequency components to Lorentzian high-frequency components for vegetation clutter, according to our measurements, is 5 dB higher than what was previously reported. Phenomena related to radar wave propagation are discussed and new measurement results concerning clear sky backscattering variations due to meteorological inversion layer are presented. A lens-effect theory proposed by Schneider (1998) is verified to be valid also in connection to long radar ranges up to 3 kilometers and for successive concave and convex terrain profiles. Furthermore, this thesis addresses several details concerning arranging and conducting practical radar measurements in true operational environments, including calibration issues and definition of antenna beamwidth in clutter measurements. A 1.2 dB uncertainty has been achieved in practical field measurements of clutter and target backscattering. Also a novel and easy-to-use approach for radar pulse width optimization has been ...
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