In this paper, we describe our approach to the localization in GNSS-denied and risky unknown environments of first responders (FRs). The INGENIOUS project is an EU funded project which is developing a new integrated toolkit to support the operations of FRs. The micro indoor-drones (MINs) developed within the INGENIOUS project represent a component of the toolkit which will support the localization of FRs in search-and-rescue (SAR) operations. In this paper, the concept behind the MINs and the current achievements are illustrated
