Remote sensing of soil surface properties

Remote sensing is now in a strong position to provide meaningful spatial data for use in soil science investigations. In the last 10 years, advancements in remote sensing techniques and technologies have given rise to a wealth of exciting new research findings in soil-related disciplines. This paper provides a critical insight into the role played by remote sensing in this field, with a specific focus on soil surface monitoring. Two key soil properties are considered in this review, soil surface roughness and moisture, because these two variables have benefited most from recent cutting-edge advances in remote sensing. Of note is the fact that the major recent advancements in spatial assessment of soil structure have emerged from optical remote sensing, while the soil moisture community has benefited from advancements in microwave systems, justifying the focus of this paper in these specific directions. The paper considers the newest techniques within active, passive, optical and microwave remote sensing and concludes by considering future challenges, multisensor approaches and the issue of scale - which is a key cross-disciplinary research question of relevance to soil scientists and remote sensing scientists alike.