LDACS1-Based Passive Radar for Civil AviationAmbiguity Function Analysis

In civil aviation, the communications, navigation, and surveillance (CNS) infrastructure is currently undergoing a major modernization process, needed to accommodate the increasing number of aircraft as well as the future air-traffic management (ATM) concepts. For the air-to-ground communication in particular, a multicarrier L-band digital aeronautical communication system, LDACS1, has been specifically designed to cover future ATM needs. Moreover, we are currently investigating the possibility to set-up a passive radar system, which uses LDACS1 signals as signals of opportunity, to serve as a non-cooperative surveillance alternative and back-up. In this work, we evaluate the self and bistatic ambiguity function of the LDACS1 signal. The results show how, the signal structure on the one hand, and the system geometry on the other hand, influence the resolution capabilities of an LDACS1-based passive radar system.