Integration of UAV-GNSS-GIS Technologies in a University Extension Project for Religious Cemetery Management: A Case Study at Martin Luther Church (Ibirama - Brazil)

Abstract. This paper presents a university extension project to improve the spatial documentation of the Martin Luther Church cemetery in Ibirama, Brazil. This was achieved by integrating Unmanned Aerial Vehicle (UAV) photogrammetry, high-precision Global Navigation Satellite System (GNSS) surveying, and Geographic Information System (GIS) mapping. A multi-altitude flight strategy (30 m, 50 m, and 80 m) combined with a network of nine ground control points, enabled the generation of high-resolution orthophotos and a digital surface model. Accuracy assessment using 24 independent checkpoints confirmed compliance with Class A of the Brazilian Cartographic Accuracy Standard (PEC) for 1:250 scale mapping. The highest-resolution orthophoto (1.4 cm Ground Sampling Distance - GSD) was used to manually digitize 1,112 graves, linked to a database containing 1,594 burial records. This study demonstrates a replicable workflow that combines open-source tools and low-cost geospatial technologies to produce precise cartographic outputs for community use.