SAM Research Areas

SAM processing in radar is concerned with detection and estimation problems resulting from the transmission and reception of electromagnetic waves at antenna arrays. In our group, we specialize in radars that operate under complex multipath propagation conditions. In particular, we have a lot of experience in developing multipath signal processing methods for HF over-the-horizon (OTH) radars which "bounce" signals off the ionosphere to detect and track targets at great distances. OTH radar has been around for awhile but is experiencing a resurgence of interest because of its potential for extremely wide area surveillance at a cost which is much lower than space-based systems. Our OTH radar research concerns signal processing for next-generation systems which will be able to finding smaller and/or slower targets in more challenging ionospheric conditions. Our current projects in this area are:

1. Aircraft Altitude Estimation

2. Adaptive Channel Compensation for Sparse Antenna Arrays

3. Adaptive Temporal Processing for Clutter Mitigation in Non-Stationary Clutter

4. Next-generation Antenna Array Design and Multiple-Input-Multiple-Output (MIMO) OTH Radar

                Range Doppler Map

Sonar was among the first applications of sensor array processing and the complications of multipath propagation in an underwater acoustic channel continue to challenge researchers in this area. There are two types of sonar: active and passive. Active sonars intentionally radiate sound into the water and thus have similarities to radar. Passive sonars, which only listen to sounds radiated by other sources, have the advantage of covertness. In our group, we have both passive and active sonar projects. In both areas, our objective is to exploit robust phenomenology of the multipath channel to perform better detection, estimation, and/or classification of underwater sources and scatterers. Our current projects in this area are:

1. Broadband passive detection and estimation using waveguide invariant processing

2. Differential delay and Doppler compensation for wideband active multi-ping processing

3. Dynamically reconfigurable sonar array processing with unmanned underwater vehicles (UUV's)

Medical imaging information is under development.

 functional MRI

• Maximum Likelihood Coordinate Registration and Mode Linking for OTH Radar

• Tropospheric Refractivity Estimation using Microwave Remote Sensing Methods

• Theoretical Performance Bounds for Sensor Array Processing Methods

• Matched-Window Processing for Coincidental Spread Doppler Clutter Mitigation

SPANDAR Reflectivity