Description: Passive Microwave Remote Sensing is currently utilized by NASA, NOAA, and USGIS to conduct Earth Science missions, including weather forecasting, early warning systems, and climate studies. Due to budgetary constraints and lack of reliable access to medium-lift vehicles, the current trend in the space industry is towards smaller, cheaper, and more frequent missions. Nano-satellites, such as CubeSats, are gaining in popularity due to their low cost and ease of deployment. These miniaturized platforms impose severe constraints on the size, weight, and power (SWaP) of the payload. However, relatively large apertures are required to achieve desired spatial resolution. In this NASA SBIR effort, Phase Sensitive Innovations (PSI) will dramatically reduce the SWaP of our microwave photonic imaging radiometer technology, thus making it amenable to deployment on spaceborne platforms. Our innovative approach employs distributed aperture imaging (DAI) with optical upconversion of the incoming microwave radiation and subsequent coherent optical reconstruction of the microwave scene. The sensor features a flexible, two-dimensional form factor that allows the antenna array to be stowed for launch and deployed once in orbit using space inflatables, which enables a large RF aperture to be realized on a small platform. Besides easing implementation on small satellites, PSI?s imaging radiometer provides capabilities beyond those currently available on conventional microwave sensors, most notably the ability to generate real-time, two-dimensional radiometric imagery with no mechanical scanning. The end result of our effort will not only greatly reduce the SWaP of our instrument commensurate with deployment on emerging platforms, but also reduce the cost and complexity while increasing reliability and performance. These improvements in turn will open up new market segments for the technology.

Benefits: The distributed aperture array technology utilized in PSI�s microwave imaging radiometer can be leveraged in a number of applications of interest to NASA. Besides passive sensing of microwave radiation from earth and other celestial bodies for weather related data, active operation is a straightforward extension for radar applications where range data is useful. High gain beam forming is readily achieved by the phased array, which is advantageous for communications and telemetry applications.

The applications for PSI?s microwave and millimeter wave imaging technology and its capabilities are numerous and could have an appreciable impact in many commercial and military areas. Millimeter wave radiation is attenuated millions of times less in clouds, fog, smoke, snow, and sandstorms than visual or IR radiation, which enables millimeter wavelength imaging systems to ?see-through? obscurants in day or night conditions. A partial list of 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 physical search