SBIR-STTR Award

This Phase I proposal is to establish the feasibility of developing a near-forward looking sonar to enhance the near-nadir bottom survey and obstacle avoidance capability for small undersea unmanned vehicles (UUV) such as REMUS. The proposed approach is a relatively simple Frequency Scanned Phased-Array (FSPA) sonar that takes advantage of the frequency dependence of the direction of phased-array beams to form multiple beams within a forward sector, mapping range and angle into time-frequency space. The FSPA approach has the flexibility to be implemented in several different beam geometry configurations, ranging from small angle sector to full two-axes coverage. The simple implementation will be practical and affordable for use in small UUV's. During Phase I we will conceptually configure a FSPA sonar to the UUV requirements, use theoretical analysis aided by experiments to validate the concept, identify the performance limitations, and specify a prototype to be developed in Phase II. The anticipated benefits of the of Phase I and II development is availability of a prototype sonar practical for use on small UUV's to enhance the near-nadir bottom survey and obstacle avoidance capability. Potential commercial applications include use on a wide range of commercial and military UUV's involved in bottom bathymetry mapping and operating in environments with obstacles.

Keywords:
Sonar, Survey, Gap-Filler , Search, Forward-Looking, Near-Nadir

This Phase II proposal is to develop, build and operationally evaluate a prototype obstacle avoidance and near nadir sonar (OAS/NNS) for use in the Semi-Autonomous Hydrographic Reconnaissance Vehicle (SAHRV). The proposed approach will combine the results of a Phase I feasibility study with an innovative array-based sonar electronics architecture, modern beamforming methodologies and state-of-the-art high frequency sonar transducer technology to provide a low power, small size, and high performance OAS/NNS capability ideally suited to a wide variety of small undersea unmanned vehicle applications. The prototype system configuration will be sufficiently flexible to be tailored to suit requirements for specific mission scenarios and applications by trading off operational parameters such as power consumption and field-of-view coverage, resolution and update rate. During the Phase II baseline effort, a methodical design analysis will be carried out to characterize and predict performance and power consumption parameters and a rapid prototyping COTS based an operational prototype will be developed and tested. The prototype will be integrated onboard the SAHRV vehicle and initial at-sea operational evaluation performed. An optional development phase will provide integration with an obstacle avoidance processor (OAP) and at-sea testing on the SAHRV vehicle.

Keywords:
UUV's, Optical avoidance sonar, Near Nadar Sonar, beamforming, imaging sonar