 This study examined the effectiveness of different numbers of ground control points, GCPs, and improving the accuracy of unmanned aerial vehicle, UAV, derived digital surface models, DSMs. It was found that the use of four or more GCPs resulted in the best overall accuracy with vertical errors ranging from 0.09 meters to 0.2 meters. Additionally, the study showed that the accuracy of the DSM increased as the number of GCPs increased, with the highest accuracy being achieved when all GCPs were located within 40 meters of each other. This article was authored by Toby N. Tonkin and Nicholas G. Midgley.