An apparatus and methods for identifying a defect and/or an operating characteristic of a system being monitored (and/or one or more of the system's components) are described. In an embodiment, orthogonally related data monitored by two or more detectors may be fused to determine whether a component of a system is defective and/or malfunctioning. Additionally or alternatively, data from a first detector may be determined to be accurate using non-orthogonally related data outputted by a second detector. Both types of determinations may be made with minimal or no false indications, which lowers the cost of operating the system being monitored. Embodiments of the invention may also be configured to forecast and/or prevent accidents and/or damage to the system being monitored by predicting whether a defect and/or a malfunction will occur.