CIF: Small: Improving Sensing and Estimation with Co-array Techniques

Detecting targets and their direction-of-arrival plays a key role in the areas of radar, sonar, astronomy, seismology and wireless communications. In the case of passive sensing with a receiver to just analyze signals intercepted, a uniform linear sensing array with N physical sensors can identify at most N - 1 targets, guided by the theoretical limit of the so-called degree of freedom (DoF) metric. Designing a sensing system with high DoF can fundamentally advance the field of sensing, detection and estimation, by increasing the capacity of such systems. The advancement is instrumental to support various applications and services that are important for national security and the economy. This project seeks to develop some fundamental techniques for active sensing to significantly increase the degree-of-freedom metric, and contribute to the advancement of sensing, detection and estimation that many applications depend upon. The investigator will incorporate the project materials into both undergraduate and graduate courses, and will facilitate participation from under-represented groups. The work falls into two major thrusts: 1) Developing a fundamental Active Synthetic Co-array that can exploit the concurrent use of principles of MIMO radar and co-arrays to surpass the sensing limit from the use of either technique alone; 2) Designing a novel two-level advanced sparse array geometry that can take full advantage of the active synthetic co-array method and flexibly integrate different array geometries in the two levels to increase the DoF up to four orders while meeting various application needs with different array structures. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.