SBIR-STTR Award

The security of the United States naval ships, ports, and waters are of tantamount importance. These crucial assets are vulnerable to attack from small, nimble adversaries that can hide within the near-constant evaporation duct present over large bodies of water. This scenario can be quite trying for conventional radar systems, which were not designed to detect and track such small vessels and objects so close to the surface of the ocean. We propose to engage this difficult scenario in two ways. First, we will develop a comprehensive electromagnetic model for radar signal propagation within the evaporation duct. We also propose to utilize the flexibility of MIMO radar systems to fully capitalize on the benefits of ducted propagation. We plan to accomplish this by developing cognitive methods to optimally adapt our transmitted waveforms and receive filters to take advantage of the evaporation duct. We propose to evaluate the performance of these methods using modeling and simulation to obtain an accurate portrait of the advantages and disadvantages of the developed methods. Finally, we plan to collect experimental data using a MIMO radar system in order to aid our understanding and refine our electromagnetic model.

Benefit:
The research performed under this proposal will yield a comprehensive model of radar signal propagation within an evaporation duct, as well as algorithms to cognitively adapt both the transmitted waveform and receive filter to this environment. These advances will benefit the Navy in the detection, localization, and tracking of objects located within the evaporation duct. In a broader context, the MIMO radar developed under this program could benefit a wide range of areas, include large-area search and rescue operations, maritime counter-drug operations, monitoring activities within the exclusive economic zone, coastal and harbor surveillance, and damage area survey after a nature disaster such as an earthquake.

Keywords:
adaptive receive filter design, adaptive receive filter design, cognitive sensing, Multiple-input multiple-output (MIMO) radar signal processing, adaptive waveform design, MIMO radar hardware, evaporation duct electromagnetic propagation.

The proposed work seeks to clearly demonstrate the advantage of the multiple-input multiple-output (MIMO) radar architecture over a similar single-input multiple-output (SIMO) or phased array system; the benefit of applying data-adaptive signal processing techniques in favor of their data-independent counterparts; and the utility of transmitting advanced probing waveforms as opposed to conventional ones. These advantages will be demonstrated through experimentation with a 2x6 MIMO radar prototype, that is capable of operating in either a SIMO or MIMO mode, and can transmit arbitrary waveforms. The experiments carried out will be approximations to challenging scenarios, such as closely spaced targets in range or bearing. The data collected during the experiments will then be processed to provide clear evidence of the aforementioned technologies.

Benefit:
It is anticipated that the MIMO radar architecture, data-adaptive signal processing techniques, and advanced probing waveforms will outperform their conventional counterparts in terms of both range and azimuthal resolving capability. However, regardless of the specific findings, the research performed under this proposal will yield a wealth of insight into the benefits and drawbacks of the MIMO radar technology, the various signal processing approaches considered, and the probing waveforms utilized. These insights can be used to focus further research and development efforts such that they become more efficient, pursuing only the most promising technologies. In a broader context, the MIMO radar, signal processing algorithms, and probing waveforms developed under this program could benefit a wide range of areas, include large-area search and rescue operations, maritime counter-drug operations, monitoring activities within the exclusive economic zone, coastal and harbor surveillance, and damage area survey after a nature disaster such as an earthquake.

Keywords:
Field radar experimentation., Multiple-input multiple-output (MIMO) radar signal processing, MIMO radar hardware, probing waveform design