Compact Passive Millimeter Wave Sensor for GPS-denied Navigation

ABSTRACT: Under the proposed effort, PSI will leverage a novel pmmW imaging technology developed under a prior Navy program to realize the low size, weight, and power sensors required for UAV implementation. This technology is based on an optical upconverted distributed aperture technology that can make use of the full aperture of the aircraft thereby maximizing achievable resolution. This sensor technology has already reached TRL 6 with successful flight tests on rotorcraft for DVE mitigation. Key elements of this effort will be to further reduce and integrate the sensor nodes and optical processor to make the technology better suited for the stricter SWaP constraints imposed by UAV platforms. Additionally, under this effort PSI will utilize existing phenomenology modelling tools and data from previous flight tests to develop sensor requirements and CONOPs for UAV navigation using pmmW sensors. These same modelling tools will also be utilized to predict the ability of the sensor to track navigation paths in terrain and geographic databases when operating in GPS denied environments. Based on these findings a preliminary sensor design for a representative UAV platform will be started in Phase I to be built as a deliverable under a Phase II effort, if awarded.; BENEFIT: The potential applications for PSIs technology and its capabilities are significant and could have a appreciable impact in many application areas. Traditional imaging modalities which exist mainly in the infrared (IR) for night vision and visible regions for daylight imaging are vulnerable to extreme scattering losses in harsh conditions. Millimeter-wave radiation is attenuated millions of times less in clouds, fog, smoke, snow, and sandstorms than visual or IR radiation. This enables millimeter wavelength imaging systems to see-through the obscurants in day or night conditions. A list of potential applications includes: (1) marine navigation in dense fog and inversion layers with passive imaging systems; (2) navigational aids for landing aircraft in adverse weather, operating emergency response vehicles in poor weather or smoke, piloting ships in poor-visibility conditions, and monitoring highways for traffic safety; (3) military surveillance and target acquisition in inclement weather with potential use on unmanned autonomous vehicles (UAVs); (4) enhanced visualization in smoke and fog, providing superior performance over infrared systems for locating victims and navigating within a fire zone; (5) non-intrusive portal security whose use would proliferate in airports, embassies, government and landmark buildings, schools, sports arenas, etc.; (6) scanners at the more than 300 ports of entry into the U.S. to look simultaneously for weapons and contraband without the need for multiple sensors; (7) stand-off frisking, providing police and security guards with the ability to detect concealed objects without the need for a physical search. More specifically, many military, security, environmental, and commercial opportunities exist for an affordable, easy to deploy system that is able to image through clothing and in harsh atmospheric condition. Passive millimeter wave imaging has the advantage over visual and infrared systems of being a near all-weather surveillance system with the ability to see through clouds and most adverse weather conditions with equal day and night sensitivity. Commercially, fog, mist, and rain cost airlines around the world billions of dollars each year in delays and rerouting. There is also the intangible cost of customer dissatisfaction. Even though Instrument Landing Systems (ILS) can help reduce weather-related flight cancellations at major airports, thousands of flights each year are canceled or delayed at smaller airports that do not have the benefit of these extensive radar and communication systems. Even with these systems, landing in inclement weather would be vastly safer and easier if pilots had a system that could see through the rain to the ground below. Civilian air transportation would benefit greatly from the proposed systems which could aid pilots in landing and navigating during Category III conditions. In such conditions now, landings are not permitted. Another large aviation market is airport security. The U.S. government has spent $15 billion on aviation screening between September 11, 2001 and 2005. Millimeter-wave imaging systems could safely and effectively monitor passengers as they enter the terminals for hidden contraband and weapons. These systems can remotely detect metallic and non-metallic threats and let security know exactly the physical location of the threat. With hundreds of commercial airports, thousands of commercial aircraft, tens of thousands of daily flights, and millions of passengers using the system daily, providing security to the nations commercial aviation system is clearly a daunting challenge. A 2007 National Academies Press book entitled Assessment of Millimeter-Wave and Terahertz Technology for Detection and Identification of Concealed Explosives and Weapons recommended that the Transportation Security Administration should follow a two-pronged investment strategy: 1.) Focus on millimeter-wave imaging as a candidate system for evaluation and deployment in the near term, and 2.) Invest in research and development and track national technology developments in the terahertz region. The development of a light weight, compact, easy to deploy, lower cost millimeter wave imaging system would open up these far reaching possibilities, representing not only an impressive leap forward in our technical capabilities but also a tremendous business opportunity. Millimeter wave imaging technology promises to establish markets in security, navigation, defense, rescue and surveillance, industrial automation, and meteorology, which are projected to grow into multi-billion-dollar segments in our national economy. PSI is uniquely positioned to directly transition this technology into the market. A lightweight, platform distributed pmmW imager, as will be developed under the proposed effort, will directly enable application to a wide range of government and commercial customers. Additionally, the navigation and guidance tools that will be developed under this effort will further expand the utility of pmmW sensors for commercial aircraft and military applications alike. PSI is continuing to develop a passive/active mmW landing aid for rotorcraft under an Army SBIR Phase II program and has received significant investment (~$1M) from one DoD prime to transition the pmmW sensor for use as a mmW landing aid in degraded visual environments. The development of integrated sensor nodes and miniaturized processors, such as the ones proposed in this effort, would directly supplement these landing aids, yielding improved performance and adding capabilities to the imaging system. Thus, these efforts will lead to a technology that will directly and immediately aid the warfighter as part of a suite of solutions for brownout mitigation for which PSI is already on a path to transition to the US military and is in direct talks with more than one prime defense contractor to transition to production.