Kriging‐based robotic exploration for soil moisture mapping using a cosmic‐ray sensor. Issue 1 (29th September 2019)

• Record Type: Journal Article
• Authors: Pulido Fentanes, Jaime; Badiee, Amir; Duckett, Tom; Evans, Jonathan; Pearson, Simon; Cielniak, Grzegorz
• Is Part Of: Journal of field robotics. Volume 37:Issue 1(2020)
• Page Start: 122
• Page End: 136
• Publication Date: 2019-09-29
• Subjects: agriculture -- environmental monitoring -- exploration -- terrestrial robotics; Robots, Industrial -- Periodicals; Automatic control -- Periodicals; 629.892
• DOI: 10.1002/rob.21914
• Languages: English
• ISSNs: 1556-4959

Abstract

Abstract: Soil moisture monitoring is a fundamental process to enhance agricultural outcomes and to protect the environment. The traditional methods for measuring moisture content in the soil are laborious and expensive, and therefore there is a growing interest in developing sensors and technologies which can reduce the effort and costs. In this work, we propose to use an autonomous mobile robot equipped with a state‐of‐the‐art noncontact soil moisture sensor building moisture maps on the fly and automatically selecting the most optimal sampling locations. We introduce an autonomous exploration strategy driven by the quality of the soil moisture model indicating areas of the field where the information is less precise. The sensor model follows the Poisson distribution and we demonstrate how to integrate such measurements into the kriging framework. We also investigate a range of different exploration strategies and assess their usefulness through a set of evaluation experiments based on real soil moisture data collected from two different fields. We demonstrate the benefits of using the adaptive measurement interval and adaptive sampling strategies for building better quality soil moisture models. The presented method is general and can be applied to other scenarios where the measured phenomena directly affect the acquisition time and need to be spatially mapped.