Abstract: Aperture synthesis microwave radiometer uses correlation interference measure technique to inverse brightness temperature and it essentially belongs to airspace Fourier transforms domain. The de-correlation effects due to propagation delay between array elements were very important to the brightness temperature inversion results. The target brightness temperature inversion algorithm was studied through spatial frequency sampling. The influences of G matrix correlation and space de-correlation effects on target brightness temperature inversion error were discussed in this paper. Base on traditional BG algorithm, a method was present to compensate space de-correlation effects and the model used to correct brightness temperature inversion error due to the bandwidth and channel inconsistent characteristic was established using de-correlation matrix.