View Project

To develop an ultra-wideband microwave scanning method that uses time reversal to achieve in situ root phenotyping non-destructively

As one of the plant’s three major organs, the root system provides functions that are central to plant fitness, such as nutrient absorption, fixation, water transmission, synthesis and storage. The spatial distribution of roots in the soil directly affects the growth and health of plants. In addition, root systems transfer carbon, which is captured from the atmospheric CO2 by plants, to soil and aid long-term soil carbon storage. A better understanding of root phenotype in situ and non-destructively is important for the research of soil and plant science, earth system science and others. Many state-of-the-art research works have been conducted for structural health monitoring and fault diagnosis in the field of non-destructive evaluation (NDE) and have made remarkable progress in the Habitat Restoration. One among the few is ultrawideband microwave imaging (UBMI) system. In this project, an UBMI system will be developed which is capable of creating a dielectric map of the scanning area by extracting the changes in both magnitude and phase in the transmitted and reflected signal. The time-reversal method will be used to create a 2D reconstruction image of the root, which can provide the size and position information of the root for habitat restoration. To verify the method’s feasibility, an electromagnetic numerical model will be studied that simulates the transmission signal of two ultra-wideband microwave antennas. The simulated signal of roots with different shapes will show the proposed system’s capability to measure the root size in the soil. Experimental validations will be conducted considering three sets of measurements with different sizes, numbers and locations, and the experimental result will indicate that the developed imaging system is able to differentiate root sizes and numbers with high contrast. The reconstruction from both simulations and experimental measurements will be provided with accurate size estimation of the plats in the soil, which indicates the system’s potential for root imaging.

An ultra-wideband microwave imaging system will be designed and developed for in situ non-destructive root phenotyping for habitat restoration purpose. The prime benefit of this work is to develop an imaging system for habitat restoration which has the ability for the real-time monitoring of a root system in a real soil environment. The proposed system will be demonstrated with the rapid scanning ability and robustness. It also enables the microwave imaging technique to be deployed in fields for scanning a large volume of soil and to access the state of the roots in a real-time manner.

This proposal will ideally open up new opportunities in science & technology and impact global science not only in terms of knowledge, but also gives potential benefits towards environment.