Towards a more robust implementation of the so-called “triangle” method: A new add-on to the SimSphere SVAT model

Abstract

The use of simulation process models combined with Earth Observation (EO) datasets provides a promising direction towards deriving accurately spatiotemporal estimates of key parameters characterising land surface interactions (LSIs). This is achieved by combining the horizontal coverage and spectral resolution of EO data with the vertical coverage and fine temporal continuity of those models. A particular promising simulation model is SimSphere, a software toolkit written in Java for simulating the interactions of soil, vegetation and atmosphere layers of the Earth's land surface. Its use is at present continually expanding worldwide both as a stand-alone application or synergistically with EO data and it is already used as an educational and as a research tool for scientific investigations. Herein, the advancements to SimSphere are presented, aiming at making its use more robust when integrated with EO data via the “triangle” method.The use of the recently introduced add-on to the SimSphere model is illustrated herein using a variety of examples that involve both satellite and UAV data. The availability of this so-called “Convolution” add-on functionality to SimSphere model is of key significance to the users' community of the “triangle” method, as between other, significantly reduces the time required for its implementation. The release of this tool is also very timely, given that variants of the “triangle” are under consideration for deriving operationally regional estimates of energy fluxes and surface soil moisture from EO data provided by non-commercial vendors.