The UWB scattered Field from 5 different classes of spheres is computed in the far-field region from 0.01 to 5 GHz, for both mono and bi-static configurations, using Mie series algorithm implemented in Matlab. The scattered field is recovered for both field components Etheta and Ephi. It is recovered for multiple observation angles where θ varies from 0° to 180° with 5° step and ϕ from -180° to 180° with 10° step. The pre-processing of the scattered Field is done by extracting the natural frequencies and their associated residues from the frequency response of each simulated object using Vector Fitting algorithm implemented in MATLAB (https://www.sintef.no/projectweb/vectorfitting/). The 5 classes of spheres are: PEC sphere, sphere with a relative permittivity er= 4 and conductivity σ= 0.5, three lossless dielectric spheres with er equal to 2, 4 and 9. They are enumerated as classes 0 to 4 respectively. To reduce the size of the datasets, we include data from only three main planes; ϕ=0° and θ varies (XoZ plane), ϕ =90° and θ varies (YoZ plane), θ=90° and ϕ varies (XoY plane). The datasets contain four parameters : natural frequencies, Q-factors and their respective residues