You are here

Precision Stabilization of Large, Wide Field of View Imaging Sensors

Description:

OUSD (R&E) CRITICAL TECHNOLOGY AREA(S): Microelectronics

 

The technology within this topic is restricted under the International Traffic in Arms Regulation (ITAR), 22 CFR Parts 120-130, which controls the export and import of defense-related material and services, including export of sensitive technical data, or the Export Administration Regulation (EAR), 15 CFR Parts 730-774, which controls dual use items. Offerors must disclose any proposed use of foreign nationals (FNs), their country(ies) of origin, the type of visa or work permit possessed, and the statement of work (SOW) tasks intended for accomplishment by the FN(s) in accordance with the Announcement. Offerors are advised foreign nationals proposed to perform on this topic may be restricted due to the technical data under US Export Control Laws.

 

OBJECTIVE: Develop a capability to accurately stabilize high performance, large, wide field of view (WFOV) imaging sensors during operations in adverse maritime environments.

 

DESCRIPTION: Imaging sensors (cameras) are used for a wide variety of purposes by naval vessels while underway. This includes general observation of the surroundings for purposes of navigation, specific search for objects both airborne and in the water, identification of other vessels, and target acquisition and tracking for weapons systems. WFOV cameras are typically used for navigation and general situational awareness while narrow-field of view (NFOV) cameras are used for target tracking and identification as well as scanning specific sectors of ocean and sky, searching for particular (and usually very small or very distant) targets. Both types of cameras require stabilization to compensate for ship motion and the buffeting effect of wind and wave during heavy sea states. NFOV cameras are almost always deployed on stabilized gimbal mounts that respond quickly to ship motion in the three axes of roll, pitch, and yaw. These cameras are used to move to a specific target cue or coordinate. Once a target is within view, these systems can employ feedback for stabilization or use inputs from inertial sensors to maintain target tracking.

 

WFOV cameras are very often used in “staring” mode. In this mode of operation, the camera does not scan or move to a target cue. The camera stares in a pre-defined direction (with respect to the platform), whether a target is present or not. In panoramic applications, multiple WFOV cameras can be assigned individual sectors of coverage and the composite image stitched together. In this way, even full 360° coverage can be achieved. However, this presents particular problems not experienced by NFOV systems. In general, WFOV imaging systems are typically larger than NFOV sensors, especially for multi-spectral systems, and their greater mass requires larger mounts and greater power input if active stabilization is to be used. In systems with 360° coverage and stitched panoramic output, the mount may be somewhat simplified since effects of ship yaw can be compensated for electronically. However, ship pitch and roll are extremely detrimental to the image quality as they inhibit proper stitching of the image and lead to images with a constantly moving horizon.

 

The Navy is fielding a suite of imaging sensors with unprecedented capability. These sensors will provide both WFOV and NFOV video imaging across a full 360° in both visible and infrared (IR) bands. Adequate stabilization technology exists for the NFOV sensors. However, the WFOV sensors present a particular challenge, as described above. The Navy needs a stabilization technology for large WFOV sensors that achieve 360° panoramic imaging through sector coverage. Currently there is no commercial capability that can meet the requirements. The desire is to provide imagery that can be efficiently processed (for example, through stitching) and achieves a stable horizon for easy viewing. Electronic stabilization cannot provide a solution in high sea states, so a mechanical solution is required. This is further complicated by the design of the sensor, which packages multiple cameras and apertures into a single unit.

For purposes of initial design and demonstration, the full sensor package to be stabilized can be viewed as a rectilinear “box”, approximately 65 inches across the face, 42 inches deep, and 29 inches high. The box has a weight not to exceed 560 lbs and a center of mass at the true center of the box. The sensor package covers a 135° sector of the vessel. The sensor package defined by this box’s dimensions must be stabilized for ship motion in ±20° roll and pitch displacement, 7.5°/sec roll and pitch velocity and 5.0°/sec2 roll and pitch acceleration (with ±40° roll and pitch displacement, 20°/sec roll and pitch velocity and 10°/sec2 roll and pitch acceleration as an objective). Stabilization to a minimum accuracy of 25 mirco-radians (15 micro-radians as an objective) in elevation is required. As an objective, the sensor package should also meet stabilization requirements while experiencing the vibration levels in MIL-STD-810H table 528.1-I. A solution that presents the minimum size, weight, and power (SWaP) necessary to achieve the required stabilization accuracy is desired. While the dimensions, weight, and center of mass listed above define the Navy’s current need, a solution that is extensible to both larger and smaller packages with variation in the center of mass represents a solution with broad utility that is highly desirable.

 

Note that the Navy does not intend to furnish tactical or otherwise representative imaging system hardware for this effort. The proposed solution should therefore include the means for test and demonstration on surrogate hardware, provided as part of the solution. A prototype (hardware and software) of the technology will be delivered to NSWC Crane Division at the conclusion of Phase II.

 

Work produced in Phase II may become classified. Note: The prospective contractor(s) must be U.S. owned and operated with no foreign influence as defined by 32 U.S.C. § 2004.20 et seq., National Industrial Security Program Executive Agent and Operating Manual, unless acceptable mitigating procedures can and have been implemented and approved by the Defense Counterintelligence and Security Agency (DCSA) formerly Defense Security Service (DSS). The selected contractor must be able to acquire and maintain a secret level facility and Personnel Security Clearances. This will allow contractor personnel to perform on advanced phases of this project as set forth by DCSA and NAVSEA in order to gain access to classified information pertaining to the national defense of the United States and its allies; this will be an inherent requirement. The selected company will be required to safeguard classified material during the advanced phases of this contract IAW the National Industrial Security Program Operating Manual (NISPOM), which can be found at Title 32, Part 2004.20 of the Code of Federal Regulations. Reference: National Industrial Security Program Executive Agent and Operating Manual (NISP), 32 U.S.C. § 2004.20 et seq. (1993). https://www.ecfr.gov/current/title-32/subtitle-B/chapter-XX/part-2004

 

PHASE I: Develop a concept for a WFOV imaging sensor stabilization system that meets the objectives as stated in the Description. Demonstrate the feasibility of the concept in meeting the Navy’s need by any combination of analysis, modelling, and simulation. Analyze the accuracy of the proposed technology in compensating for ship motion. The Phase I Option, if exercised, will include the initial design specifications and capabilities description necessary to build a prototype solution in Phase II.

 

PHASE II: Develop and deliver a prototype sensor stabilization system based on the concept, analysis, preliminary design, and specifications resulting from Phase I. Demonstrate the technology using a surrogate payload in place of the Navy’s imaging sensor package in either actual or simulated sea states sufficient to achieve the roll and pitch described above.

 

It is probable that the work under this effort will be classified under Phase II (see Description section for details).

 

PHASE III DUAL USE APPLICATIONS: Support the Navy in transitioning the technology for Government use. Develop specific hardware, software, and operating instructions for specific Navy imaging sensors. Establish hardware and software configuration baselines, produce support documentation, production processes, and assist the Government in the integration of the stabilization technology into existing and future imaging sensor systems.

 

The technology resulting from this effort is anticipated to have broad military application. In addition, there are scientific and commercial applications, for example, the stabilization of telescopes and motion picture cameras.

 

REFERENCES:

  1. Miller, John L., et al. "Design challenges regarding high-definition electro-optic/infrared stabilized imaging systems." Optical Engineering 52.6 (2013): 061310-061310. https://www.spiedigitallibrary.org/journals/optical-engineering/volume-52/issue-6/061310/Design-challenges-regarding-high-definition-electro-optic-infrared-stabilized-imaging/10.1117/1.OE.52.6.061310.short?SSO=1
  2. Short, Robert E., et al. "Holistic approach to high-performance long-wave infrared system design." Optical Engineering 58.2 (2019): 023113-023113. https://www.spiedigitallibrary.org/journals/optical-engineering/volume-58/issue-2/023113/Holistic-approach-to-high-performance-long-wave-infrared-system-design/10.1117/1.OE.58.2.023113.short
  3. Larry A. Stockum, George R. Carroll, "Precision Stabilized Platforms for Shipboard Electro-Optical Systems," Proc. SPIE 0493, Optical Platforms, (23 October 1984); https://doi.org/10.1117/12.943843
  4. Watson, Edward A., Donald T. Miller, and Paul F. McManamon. "Applications and requirements for nonmechanical beam steering in active electro-optic sensors." Diffractive and Holographic Technologies, Systems, and Spatial Light Modulators VI. Vol. 3633. SPIE, 1999. https://www.spiedigitallibrary.org/conference-proceedings-of-spie/3633/0000/Applications-and-requirements-for-nonmechanical-beam-steering-in-active-electro/10.1117/12.349329.short
  5. MIL-STD-810H, Environmental Engineering Consideration and Laboratory Tests, Revision H w/ Change 1, 2022. https://quicksearch.dla.mil/qsDocDetails.aspx?ident_number=35978

 

KEYWORDS: Stabilization; Imaging Sensor; panoramic imaging; Wide Field of View; WFOV; video imaging; Narrow Field of View; NFOV

US Flag An Official Website of the United States Government