In order to verify the theory of aperture synthesis at low expense, two-channel ka-band correlation radiometer which is
basic part of synthetic aperture radiometer is designed firstly before developing the multi-channel synthetic aperture
radiometer. The performance of two-channel correlation radiometer such as stability and coherence of visibility phase
are tested in the digital correlation experiment. Subsequently all required baselines are acquired by moving the antenna
pair sequentially, corresponding samples of the visibility function are measured and the image of noise source is
constructed using an inverse Fourier transformation.