Performance Measures for an Automated Navy Tactical Sounder System (NTISS).

Renewed interest by the Navy in the HF Radio Band has raised questions about the utility of the Navy Tactical Sounder System NTSS as part of the new systems of the 1980 and 1990 decades. NTSS was designed in the 1950s and used intermittently from 1960 to the present day. Funding and support for the system are currently undergoing reevaluation. In light of recent advances in digital technology and communication theory, it seemed propitious to reexamine the fundamental signal design and processing algorithms of the UPR-2 sounder receiver. The long term objective is a better receiver design easily implemented with microcircuit technology. This report covers the first step in this process, deriving performance measures related to signal detection and processing. The signal transmitted by the NTSS is essentially a channel probe meant to characterize the ionospheric path. The received signals contain information about path losses, time delays and frequency dispersion. From these basic parameters one can construct a channel model that can be used to estimate communication performance for any HF circuit. Channel performance metrics related to signal-to-noise ratio, error rate, synchronization and timing accuracy, multipath, fading, attenuation, and MUF and LUF can be extracted from the sounder receiver and used for management purposes. Thus NTSS serves as a feedback linkor feed forward for the express purpose of improving communications. Three performance measures are evaluated 1 probability of detection 2 probability of false alarm and 3 timing resolution.