Method for Obtaining Three- and Four-Element Array Spacing for Interferometer Direction-Finding System

A number of methods are available to obtain the spacing of three- and four-element arrays for a phase interferometer direction-finding (DF) system. Although these methods provide the array spacing having no angle ambiguity, some of these methods do not provide the information about phase error. Furthermore, some methods offer the phase error information but present the limited number of array spacings. The method proposed in this letter provides array spacings that satisfy the maximum phase error that is required at interferometer DF system by using the phase-difference and rotation matrices.