Complex gain calibration in “hybrid” low-frequency aperture arrays: An array prototype and the Murchison Widefield Array

Complex gain calibration is a process which solves and corrects for the composite effects of the unknown electronic and antenna gains from the uncalibrated cross-correlation products (“visibilities”) in radio interferometry. The resulting calibrated visibilities form the basis for astronomical post-processing such as imaging and telescope sensitivity measurements. Clearly, complex gain calibration is an essential prerequisite step.