- Data acquisition is the foundation of sound decision making. Therefore, after the work of the empiricist who laid the philosophical foundation of the data driven inference (Berkeley, 2003; Hume, 1902; Locke, 1860), significant efforts were carried in developing methods aiming at acquiring representative information for describing reality. The main instrument created to provide unbiased representation of reality was sampling (Avery and Burkhart, 2015; Cochran, 1977; Gillis et al., 2007; Johnson, 2000; Kershaw et al., 2017). However, the strength of sampling, which is selection of a reduced number of individuals from a population, became its weakness in the current technological savvy era. Remote sensing is one of the current technologies that matured to the point of being able to provide data that allows extraction of the relevant information for all the members of a population. Among the remote sensing technologies, the one relying on unmanned aerial vehicles is without the doubt the newest one. The advent of unmanned aerial systems (UAS) is rooted in traditional aircraft experience, but it’s explosive development is based on computer science and material sciences. Miniaturization of devices without compromising the computation power allowed for controlling the UAS during the flight without addition of heavy equipment. Computer sciences has also helped on the data processing front, as there is no need for placing sophisticated devices on the UAS to measure the location and angles of the unit during the flight. Techniques such as Structure from Motion (SfM) or Simultaneous Location and Mapping (SLAM) allows for acquisition of images with poor location information from which accurate orthorectified images are produced. The material sciences also contributed significantly to the increased usage of UAS, as it developed multiple sensors, ranging from ultraviolet to long wave infrared, at a reduced costs. Cameras such as Rededge or FLIR Vue Pro revolutionized how we look at the surrounding reality. Being at the beginning of a predicted long road, the UAS based investigations are marred by limited agreement in terms of terminology and approaches. Therefore, it is necessary to have materials that summarize the existing body of literature at a certain point in time, which will serve as benchmarks through time. Consequently, the objective of this document, conceived as a manual, is to provide a summary of the existing approaches and regulations governing the current UAS based investigations. The material presented in the manual is designated for practitioners and researchers actively using the UAS, and can be used by recreational users. The document has three components, one dedicated to the UAS regulations, one to flight preparation, and one to image processing. The manual can be used for teaching and as a hands-on guide.