Abstract. Systems supporting situation awareness typically integrate information about a large number of real-world objects anchored in time and space provided by multiple sources. These sources are often characterized by identical, incomplete, and even contradictory information. Because of that, duplicate detection methods are of paramount importance, allowing to explore whether or not information concerns one and the same real-world object. Although many such duplicate detection methods exist, a recent survey revealed that the characteristics of situation awareness--highly dynamic and vague information, which is often available in qualitative form only--are not supported sufficiently well. This paper proposes concepts for qualitative duplicate detection to cope with these key issues of situation awareness based on spatio-temporal relations between objects.