In the recent years, the field of metrology has received more and more attention by the Earth observation community, which has led to a growing awareness of the concept of error tracability and the necessity of fiducial reference measurements. As a consequence, research has put a new focus on obtaining tracable error budgets for soil moisture products. These efforts are further fuelled by an unprecedented wealth of standardized group data repositories like the International Soil Moisture Network (ISMN) and satellite Cal/Val networks, which enable new ways of assessing data quality. At the same time, the increasing availability of high-resolution soil moisture data sets, including downscaled products from coarse-resolution missions such as the SMOS and SMAP missions as well as retrievals from high-resolution SAR missions such as the Sentinel satellites, requires the refinement and adaptation of established community-agreed validation good practice guidelines and protocols to correctly characterize the error budgets of soil moisture products across scales. Lastly, reliable knowledge about soil moisture product error budgets is vital to maximize their utility across applications, most importantly data assimilation.
Particlulary encouraged are submissions related to:
- Soil moisture reference networks, especially the establishment of fiducial reference measurements (FRM)
- Tracability and metrological principles
- Novel statistical methods and tools
- Characterizing uncertainties across scales
- Soil moisture product assessments
- Uncertainty characterization for data assimilation
- The utility of uncertainty estimates for other applications