DON26BZ01-NV019 — Improved Portable Underway Replenishment (UNREP) Tester/Trainer (Copy)

Award Maximum: $140,000 (Base) / $100,000 (Option) Period of Performance: 6 months (Base) + 6 months (Option) Phase Type: Phase I

OBJECTIVE: Develop an auto-focus signal processing capability to optimize detection of quiet contacts by arrays of hydrophones.

DESCRIPTION: Arrays of hydrophones are used to detect, classify, and localize contacts in the ocean environment. Finding a contact, especially a quiet contact, is extremely challenging due to the large volume of data that needs to be searched as well as the large number of other noise sources (e.g., shipping, fishing, whales, etc.) that generate clutter on the displays.

Array signal processing, also known as beamforming, steers many beams to spatially filter the noise environment and generate a 3-D data volume that is a function of time, frequency, and bearing (i.e., steered beam) that are processed to generate several detection surfaces.

Several parameters can be adjusted to optimize the detection of a signal on an array. One of these parameters is focus range. However, only a limited number of display surfaces are typically generated due to processing constraints, and this may not provide the best opportunity to detect all signals.

Automation approaches have been developed for decades to help reduce operator workload. However, a well-trained operator can still detect lower Signal to Noise Ratio (SNR) signals than the state-of-the-art automation. The main reason for this is if the automation detection threshold is adjusted to detect lower SNR signals, it will cause an increase in the number of false alerts that detracts from the search process.

The objective of this SBIR topic is to develop a signal processing approach that will auto-focus on the signal processing (much like a digital camera does) with respect to parameters such as focus range. There is currently nothing available commercially.

The easiest example to understand is range focusing. If we process a single far field focus range, then close-range contacts may barely be detected. Instead, if we process several focus ranges from close to far, there will be one focus range where each contact displays the clearest signal with the highest SNR. The innovative part of this SBIR topic is the use of this larger data volume to build a combined display that contains the best representation of every available signal.

Overall, it is expected that this auto focus approach will allow system gains that are currently not being realized with the current signal processing and automation approach. This would significantly improve system performance by providing earlier detections and longer holding times of contact without increasing the operator workload or requiring a complete overhaul of the signal processing and automation framework.

Work produced in Phase II may become classified.

PHASE I: Develop a concept for a technical approach for implementing an auto-focus signal processing and automation capability that accomplishes the intent identified in the Description. Demonstrate this approach by using the focus range parameter as an example using an unclassified simulated dataset. Establish feasibility through analysis and modelling. During the Phase I period of performance, the government team will provide the simulated dataset. The Phase I Option, if exercised, will include the initial design specifications and capabilities description to build a prototype solution in a Phase II plan.

PHASE II: Develop and deliver a prototype auto-focus signal processing and automation capability using additional optimization parameters identified by the Government team. This will be implemented as a research code and tested against classified datasets provided by the Government to the Phase II awardee(s). Deliver a prototype, software description document, a working copy of the development code, and test results from processing two or more classified datasets. It is probable that the work under this effort will be classified under Phase II.

PHASE III DUAL USE APPLICATIONS: Support the Navy in transitioning the technology to Navy use to allow for further experimentation and refinement. Develop production level code that is containerized and assist with integration efforts to incorporate the SBIR-developed code into the Government's Processing Testbed (PTB). This technology does have significant dual-use applicability. The underlying concept is built upon array processing fundamentals that are applicable to SONAR, RADAR, communications, geophysical exploration, astrophysics, and biomedical imaging.

KEYWORDS: SONAR; Array Signal Processing; Surveillance Automation; Acoustic Detection; Acoustic Target Classification; Sonar Operator Workload