Grain bin storage monitoring via microwave imaging

This work investigate the use of MWI as a technique for monitoring the conditions of stored wheat and discuss the obstacles to be overcome for MWI to be a cost-effective solution to the grain spoilage problem. Experimental results obtained on a small scale, from a novel near-field MWI system developed in the Electromagnetic Imaging Lab (EIL) at the University of Manitoba, show that the difference between dry and wet grain can be detected in principle. The challenges of performing MWI imaging inside of full-size hopper bins, where the boundary of the imaging domain is modeled by a perfect electric conductor, are investigated. Included are: comparisons of the sensitivities of different measurement systems, including the microwave scatterer technique (MST); results from different inversion algorithms such as FEM-CSI and eigenfunction Gauss-Newton inversion; a discussion of antenna designs suitable for the pressures, sheer forces and abrasion conditions inside grain bins; and a discussion of calibration methods.