R package to support Remote Sensing oriented field work. It was developed at the University of W├╝rzburg, Germany, as part of the project Research Network Water in Central Asia (CAWa) funded by the German Federal Foreign Office. It is part of the German Water Initiative for Central Asia (the so-called Berlin process), which the German Federal Foreign Office launched on the 1st of April of 2008 to support peaceful, sustainable and mutually beneficial management of transboundary water resources in Central Asia. fieldRS was designed to ease the collection and management of ground truth data. It provides tools that help select sampling sites, correct and pre-process training data and preview classification results in order to identify potentially incorrect samples.