Abstract: Thinned rotating arrays of microwave/millimeter wave synthetic aperture imaging radiometer result in polar like visibility samplings where complex image reconstruction algorithms are in need and it is tough work to estimate important system parameters. To address this problem, a new method based on filtered back projection algorithm is proposed. In this approach, the system Point Spread Function (PSF) is obtained by 1-D Fourier-Bessel (Hankel) transforming from Dirac comb?function. Spatial resolution and alias-free of view affected by radial and angular sampling intervals are analyzed by decomposing PSF into main lobe and a series of ring lobes. A new formulation to estimate the radiometric sensitivity of thinned rotating arrays by filtered back projection algorithm is also proposed. The consistency between the numerical and measured point spread function indicates that the proposed model is accurate.