See-through Soil Measurements at 300 GHz

Over time, terahertz waves (T-waves) have succeeded in gaining a foothold in various areas ranging from localization, imaging, communications, to characterization. Due to several unique properties and abilities of T-wave, groundbreaking applications in real-time continuous monitoring of plant growth and health are conceivable. Nevertheless, a motivation for developing THz medical-style non-invasive imaging systems to diagnose plant health demands prior knowledge of soil attenuation. This paper features preliminary results from seethrough soil experiments conducted with soils of different ages at 275-325 GHz employing a THz-VNA bistatic setup. Proceeding further, the measurements are recorded in three experiment scenarios to acknowledge the pivotal role of soil in maintaining the availability of water and nutrients to the aerial parts of a plant. For this purpose, the soil is moistened with 100, 200, 300, and 400 ml water to record the resulting impact on the plasticity of the soil. This study thus confers that T-wave can see-through soil samples possibly up to 25 cm thick supported by THz-VNA - state-of-the-art technology.