Feasibility of range estimation using sonar LPI

Abstract

Using a detailed waveform-based simulation framework, a study on the feasibility of LPI sonar is performed for covert range estimation. A frequency selective channel filter is applied for realistic ocean simulation. The platform uses matched filtering and the target uses energy detection for processing the received signal. The objective of the platform is to estimate the range to the target while ensuring that the target still fails to detect the platform's pinging LPI waveform. A platform-target encounter scenario was designed for Monte Carlo simulation. Evaluation of system parameters was performed to assess for the feasible conditions for covert range estimation.

Low Probability of Detection for Underwater Acoustic Communication: A Review

“…Also military surveillance systems use UWAC, for example when mobile devices such as autonomous underwater vehicles (AUVs), drifters such as gliders and underwater buoys, and human divers require either peer-to-peer or network communication capability for threat detection and long range survey. While covert transmission is also required for active sonar activities for estimating the range to an object without being detected [2], the majority of applications for low probability of detection (LPD) involves underwater acoustic communications. For military applications, LPD is of interest when the transmitter (e.g., a submarine) wishes to remain undetected, or when the mere knowledge of communication may point to the existence of a receiver (e.g., a diver).…”

“…Second, the strong location dependency of the UWAC channel [36], makes it essential to consider different attenuation models for the receiver and interceptor in calculating the LPD capability. Furthermore, without accurate bathymetry information 2 it is difficult to model the UWAC channel reliably and bounds need to be used to calculate the reception and interception ranges. Third, LPD transmission and reception methods are challenged by typically long and fast time-varying channel impulse responses, which require high complexity and fastconvergence equalizers.…”

“…It consists of a transmitter with an associated legitimate receiver and an interceptor located in some proximity of the transmitter. Given several basic transmission parameters (e.g., the packet duration and the bandwidth of the communication 2 Bathymetry refers to a topographic map of the sea bottom with depth indication. Bathymetry is mostly obtained in multibeam surveys.…”