Algorithms for MIMO Techniques to Enable a Coherent Distributed Array from Multiple Airborne Platforms

TECH FOCUS AREAS: Microelectronics; Autonomy; General Warfighting Requirements (GWR) TECHNOLOGY AREAS: Sensors; Electronics; Air Platform; Battlespace OBJECTIVE: Develop a set of algorithms to use sub-wavelength time and phase synchronization to increase performance of multiple, cooperating airborne sensors for multi-function RF applications. DESCRIPTION: The ability to use Precision Navigation and Timing (PNT) on the order of picosecond and nanosecond accuracy can provide the needed phase synchronization to enable multiple airborne platforms to achieve phase coherence on receive and transmit. This phase coherence theoretically enables a constellation of UASs to perform as a large distributed aperture and provide performance gains to radar, jamming, and communications which have been up to this point unattainable. There are many efforts to provide the hardware architecture to enable the synchronization of time and phase across multiple channels and platforms. This effort will concentrate on developing the algorithms and methods necessary to process both the transmitted and received pulses of multiple platforms and aggregate them into a single radar detection or jamming waveform at the target location. After the algorithms are developed, a simulation that considers the sensitivity of algorithm performance due to both timing errors that can be modeled as a statistical mean and standard deviation of the clock delay and errors from an onboard INS/IMU that will provide position and velocity estimates of each source. Finally, the model should be improved to consider the traditional errors in a radar system that may include but are not limited to possible clutter effects, radar noise, and any propagation effects. PHASE I: Demonstrate and model algorithms to prove the feasibility of using phase coherence to establish increased detection or jamming performance at a single STATIONARY point target from multiple platforms in flight. PHASE II: Demonstrate and model algorithms that can use phase coherence to establish increased detection or jamming performance at multiple STATIONARY point target from multiple platforms in flight. PHASE III DUAL USE APPLICATIONS: Demonstrate and model algorithms that can use phase coherence to establish increased detection or jamming performance at multiple MOVING point targets from multiple platforms in flight. NOTE: 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 proposed tasks intended for accomplishment by the FN(s) in accordance with section 5.4.c.(8) of the Announcement and within the AF Component-specific instructions. Offerors are advised foreign nationals proposed to perform on this topic may be restricted due to the technical data under US Export Control Laws. Please direct questions to the Air Force SBIR/STTR Contracting Officer, Ms. Kris Croake, kristina.croake@us.af.mil. REFERENCES: 1. https://www.sbir.gov/node/1144419 2. S. Coutts, K. Cuomo, J. McHarg, F. Robey and D. Weikle, "Distributed Coherent Aperture Measurements for Next Generation BMD Radar," Fourth IEEE Workshop on Sensor Array and Multichannel Processing, 2006., Waltham, MA, USA, 2006, pp. 390-393, doi: 10.1109/SAM.2006.1706161 3. S. M. Ellison and J. A. Nanzer, "High-Accuracy Multinode Ranging For Coherent Distributed Antenna Arrays," in IEEE Transactions on Aerospace and Electronic Systems, vol. 56, no. 5, pp. 4056-4066, Oct. 2020, doi: 10.1109/TAES.2020.2985251