Description
Objective: Develop a technology to determine the range of multiple, simultaneous, widely spaced, and independently moving small airborne targets using electro-optical/infrared (EO/IR) means. Description: The Navy fields, and continuously updates, multiple systems incorporating imaging sensors (cameras). Across all systems, the Navy will have cameras covering both wide and narrow fields of view, operating over essentially the entire span of visible to infrared (IR) wavelength bands. While there is no strict operational division, wide field of view (WFOV) cameras typically provide general situational awareness over a broad sector. When an object of interest is observed, the WFOV camera system then provides coordinates (azimuth and elevation angles) to cue narrow field of view (NFOV) cameras for high magnification imaging of the object. If the target can then be positively identified and is of a known type (for example, a cargo ship or commercial airliner), its range might then be inferred. Otherwise, or when precise range information is required, a laser rangefinder may be employed. Laser rangefinders and NFOV cameras are typically deployed in stabilized gimbaled mounts, providing full degrees of freedom and precise aiming. They are valuable and expensive resources. A challenging problem arises when multiple targets are simultaneously present in the sector covered by a WFOV camera. While the WFOV camera images the targets and calculates their relative coordinates instantly, the NFOV cameras and rangefinders must mechanically slew to each target and hold on that target for some finite moment in order to effectively focus the image and capture the range data. This is a significant problem if the targets are small, widely dispersed throughout the field of view, and maneuvering independently, especially at high speed. As the number of targets grows, the point is reached where the NFOV camera and the range finder (often mounted on the same gimbal) simply cannot move fast enough to follow every target. Airborne targets can be exceptionally challenging to cover because they are free to move in three dimensions and because they can typically maneuver at much higher velocities than surface targets. Alternately, small surface targets are often obscured by more severe clutter conditions due to wave action but move slower and are confined to the ocean surface. Consequently, swarms of surface and airborne targets present entirely different problems in detection and range determination. There is currently no commercial technology known that solves this problem. The Navy needs an EO/IR sensing technology that can rapidly determine the ranges of large numbers of small, independent, rapidly maneuvering airborne targets in complex raid scenarios. Solutions may employ active means, semi-active means, or passive means. In this regard, “active means” refers to a laser-based solution, such as a lidar or conventional laser rangefinder where the solution incorporates a laser (or multiple lasers), a dedicated receiver for detecting the laser return(s), and an appropriate steering or scanning mechanism, all mounted together. A “semi-active” solution would incorporate a laser (or multiple lasers) but would make use of the separate and already available WFOV imaging sensors to detect the laser return. For this purpose, WFOV cameras can be assumed to be available in the visible and mid-wave IR (MWIR) bands. A strictly passive solution would determine range solely by the (optional) utilization of existing WFOV cameras and any passive imaging sensor necessary to augment the WFOV cameras. Cost is always a factor and WFOV cameras are expensive and typically require a dedicated aperture, which further increases system cost and complexity. Therefore, solutions that require the modification of existing WFOV cameras or the incorporation of additional WFOV cameras are excluded from consideration. Utilization of the ship’s existing NFOV cameras is also not permitted. Solutions that require a library of target images or signatures are also not allowed. Because of blockages from the ship superstructure, the maximum azimuthal field of regard is 190 degrees (180-degree coverage plus 5-degree margin at either end) and 45-degree elevation. However, for purposes of the prototype delivered under this effort, design for and demonstration of 45-degree azimuthal coverage is acceptable, provided that the solution can be readily extended to the full field of regard without loss of performance. As an initial performance baseline, consider ten airborne targets randomly scattered over the field of regard, both in azimuth and elevation. Range measurements for these ten targets should be refreshed at a minimum rate of once per second (for the full 190-degree field of regard). It is understood that the measurement refresh rate may slow proportionately as the number of simultaneous targets increases. A nominal range resolution of ±1.0 m at 1000 m range is desired. For active and semi-active solutions, maximum usable range is assumed to scale with laser power. For the prototype demonstrated under this effort, an eye-safe condition at the emission aperture is desired with the understanding that (future) tactical units may require higher power. Consequently, for solutions that incorporate lasers, system architectures that permit scaling of the laser power are most attractive. Conversely, indiscriminate beaming of laser energy can interfere with nearby Navy and civilian aircraft so, for the case of active and semi-active solutions, a low probability of intercept technology is also desired. The technology developed under this SBIR topic is not expected to detect new or otherwise previously unobserved targets. This topic assumes that targets are visible to and have been detected by the WFOV cameras. Consequently, target coordinates in azimuth and elevation may be assumed to be available to the range measurement system. Likewise, for active and semi-active solutions, sector blanking (that is “do not lase”) coordinates should also be accommodated. In short, the desired ranging technology is expected to interface, work, and compliment the ship’s existing WFOV camera(s). However, the Navy cannot provide tactical hardware, and it is incumbent on proposers to include surrogate hardware (or emulation software) that replicates the function of a WFOV staring (fixed) camera. A test plan that includes representative targets should also be included as part of the proposed solution. Considering the requirements and objectives described above, system complexity and cost is the next most relevant factor. Systems that incorporate more than one laser or sensor element should strive to use a single aperture. If a dedicated focal plane array is included, it should be of the smallest possible size and cost and increase system complexity as little as possible. Mechanical components such as gimbals, steering mirrors, and scanning mechanisms should be minimized and made as simple as possible to reduce acquisition cost, ease repair, and maximize reliability. 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. Keywords: Range Measurement; Raid Scenarios; Airborne Targets; Laser Rangefinders; Imaging Sensors; Low Probability of Detection CMMC Level: Level 2 (Self)