Multiple Grazing Angle Electromagnetic Propagation and Scattering in Non-Standard Atmosphere
Abstract
The ultimate objective of this research is to advance the field of detection, discrimination,tracking, and fusion of data of difficult targets in rapidly varying non-standard atmosphericconditions utilizing electromagnetic theory and situational awareness methodologies, and toimprove communication link design and performance analysis under ducting conditions. Hence,understanding and correctly characterizing the propagation between the transmitter/receiver orradar/target is important to US Navy.The specific goal in the proposed research is the study of the complex characteristics of lowgrazing angle propagation in non-standard atmospheric conditions. Some of the work proposedand questions we want to answer are:1. Understanding and development of numerical tools that accurately compute multiple grazingangles and capture RF propagation, both forward propagating and scattering, under nonstandardconditions with height and range-dependent refractivity.2. Grazing angle has always been an important nuisance parameter in remote sensing of ductingconditions since it changes with range and the surface backscattering is a function of angle.Most refractivity estimation algorithms assume they know the angle or use someapproximations to get rid of the grazing angle dependence. Here we propose development andtesting of standard and Bayesian refractivity-from-angle of arrival (RFA) inversion algorithmsthat will be able to statistically estimate the ducting conditions from the amplitudes and anglesof arrival.3. Determination of conditions including but not limited to duct types and parameters such asduct strength and thickness, frequency of operation that lead to significant multiple grazingangle formation.4. Determination of the regions/times that multiple grazing will going to be most prevalent.5. Design, manufacturing, and demonstration of a Purposefully-aliased Ultrawide-band SparseHigh-resolution (PUSH) array that can measure grazing angles in ducting conditions.6. Conducting concurrent EM and atmospheric measurements to test the theoretical/numericalmodels developed using both the PUSH array and the Lower Atmospheric Propagation System(LATPROP) built under Dr. Yardim???s supervision with ONR funding.7. Studying target scattering and ship radar signature (basic stealth geometries, in particular) inthe presence of multiple grazing angle incident signal.
Document Details
- Document Type
- DoD Grant Award
- Publication Date
- Jul 26, 2018
- Source ID
- N000141812589
Entities
People
- Caglar Yardim
Organizations
- Office of Naval Research
- Ohio State University
- United States Navy