Methodology of construction of correlation-extreme systems of navigation and guidance of aircrafts, invariant to instability of geophysical field and influence of interference is presented. The main attention is paid to the method of forming an informative parameter of the geophysical field, invariant to the main factors of its instability. Unlike previously used approaches, the informative parameter is considered as a vector quantity. This creates the potential to counteract or substantially reduce the effects of disturbances (instability factors and geophysical field interference) on the received signal by analyzing its fine structure.