Bandwidth smearing

Bandwidth smearing is a chromatic aberration of the reconstructed image of a celestial body observed by an astronomical interferometer that occurs because of the frequency bandwidth. In Fourier terms, the different frequencies of the bandwidth probe different spatial frequencies which results in a reconstruct map containing elongated radial features.

It is overcome by going to higher spectral resolutions or, in radioastronomy, by using different centres of phase for image reconstruction.