  We explore non-redundant aperture masking to derive the size and shape of the
ALBA synchrotron light source at optical wavelengths using synchrotron
radiation interferometry. We show that non-redundant masks are required due to
phase fluctuations arising within the experimental set-up. We also show, using
closure phase, that the phase fluctuations are factorizable into element-based
errors. We employ multiple masks, including 2, 3, 5, and 6 hole configurations.
We develop a process for self-calibration of the element-based amplitudes
(square root of flux through the aperture), which corrects for non-uniform
illumination over the mask, in order to derive visibility coherences and
phases, from which the source size and shape can be derived. We explore the
optimal procedures to obtain the most reliable results with the 5-hole mask,
based on the temporal scatter in measured coherences and closure phases. We
find that the closure phases are very stable, and close to zero (within $2^o$).
Through uv-modeling, we consider the noise properties of the experiment and
conclude that our visibility measurements per frame are likely accurate to an
rms scatter of $\sim 1\%$.
