DAHLGREN, Va. –
“You can’t hit what you can’t see…” were the words of Washington Senators pitcher Walter “Barney” Johnson 100 years ago. Today, his baseball wisdom describes the goal of some of the most cutting-edge testing and evaluation happening at Naval Surface Warfare Center Dahlgren Division (NSWCDD) in the Laser Weapon System Integration and Weaponization Branch: identify the best-in-class imagers for the next generation of point-targeting systems.
One such system, the Portable Laser System (PLS) is equipped with several cameras that allow PLS to see a high level of detail at a distance and perform complex alignment functions that provide game-changing intelligence, surveillance and reconnaissance capabilities. Selection of the system imagers was critical, as was reducing the human error often found in imager selection.
Traditionally, imager comparison is similar to a visit to the eye doctor: test subjects visually compare images from each sensor and select the one that appears to be the best quality. This approach has several issues including individual bias, the limits of the human eye and the highly environmentally-dependent nature of imager testing. The traditional method is vulnerable to user subjectivity and is therefore not reliably repeatable, requiring increased manpower to gather enough data to conduct sufficient analysis.
To accomplish the task of PLS imager selection, the NSWCDD team conducted field testing of multiple imagers, and then compared the results using a novel edge-identification approach – but the NSWCDD team did not do it on their own. Collaborative efforts spanned across multiple departments throughout the Navy, as well as private industry. Camera Sensor and Atmospheric subject matter experts at the Naval Research Laboratory (NRL) shared test validated imager performance models aiding evaluation of imagers. Another NSWCDD team provided operationally relevant environmental camera selection data and industry partners gave hands-on interactive training that enabled the NSWCDD team to successfully down select the best of each type of imager.
Field testing of the imagers selected for the study occurred over four months, in a wide range of environmental conditions. The NSWCDD team tested each camera, provided by various industry vendors, in operationally-relevant environmental conditions across various distances. The team familiarized themselves with each system’s components, software and equipment. Since PLS required imagers that would need to perform under very harsh environmental conditions, demonstrating each camera’s capability in a specific environment was imperative for selection.
Once the NSWCDD team completed the test series, the imaging data was compiled, analyzed and compared using a novel algorithm-based analytical approach developed by the project to numerically ‘grade’ each imager. This numerical analysis eliminated the human test subject needed for the traditional approach and controlled for variations in environmental conditions. To validate this novel analytical approach, the NSWCDD team also conducted a qualitative “eye-doctor” style test. The NSWCDD team weighted the compiled quantitative and qualitative data in order to select the appropriate imagers to meet project requirements. The results of the novel approach corroborated the traditional qualitative testing, but was much more objective, and efficient in grading the performance of each sensor. The novel approach enabled the test team to analyze each image in a manner that was quantifiable, repeatable and utilized only a single individual, significantly decreasing required manpower.
Now that the NSWCDD team knows they have the best imager for seeing what they need to hit, the program is rapidly moving toward integration of the imagers and designing the surrounding components to optimize imaging capabilities while meeting other key project requirements.
The tailored testing and evaluation demonstrated by the NSWCDD PLS team has already been adopted by other Directed Energy projects at NSWCDD in their selection of imagers and other required components. Looking ahead, NSWCDD will continue to test and evaluate critical design components in tailored environments to demonstrate current capabilities to future sponsors and customer representatives.