  Spatial coherence plays an important role in several real-world applications
ranging from imaging to communication. As a result, its accurate
characterization and measurement are extremely crucial for its optimal
application. However, efficient measurement of an arbitrary complex spatial
coherence function is still very challenging. In this letter, we propose an
efficient, noise-insensitive interferometric technique that combines wavefront
shearing and inversion for measuring the complex cross-spectral density
function of the class of fields, in which the cross-spectral density function
depends either on the difference of the spatial coordinates, or the squares of
spatial coordinates, or both. This class of fields are most commonly
encountered, and we experimentally demonstrate high-fidelity measurement of
many stationary and non-stationary fields.
