Estimation of the Block Adjustment Error in UAV Photogrammetric Flights in Flat Areas

Remote Sensing

Juan F. Prieto¹  Juan Pedro Carbonell-Rivera²  Alba Nely Arévalo-Verjel³  José Luis Lerma³  José Fernández⁴ 

[1] ETSI Topografía, Geodesia y Cartografía, Universidad Politécnica de Madrid, Ctra. Valencia km 7, 28031 Madrid, Spain;Geo-Environmental Cartography and Remote Sensing Group (CGAT), Universidad Politécnica de València, Camino de Vera s/n, 46022 Valencia, Spain;Grupo de Investigación en Fotogrametría y Láser Escáner (GIFLE), Departamento de Ingeniería Cartográfica, Geodesia y Fotogrametría, Universitat Politècnica de València, Camino de Vera s/n, 46022 Valencia, Spain;Institute of Geosciences (IGEO), CSIC-UCM, Calle del Doctor Severo Ochoa, 7, Ciudad Universitaria, 28040 Madrid, Spain;

关键词: UAV;    UAV-DAP;    aerial close-range photogrammetry;    GCP;    flight planning;   

DOI  :  10.3390/rs14122877

来源: DOAJ

【 摘 要 】

UAV-DAP (unmanned aerial vehicle-digital aerial photogrammetry) has become one of the most widely used geomatics techniques in the last decade due to its low cost and capacity to generate high-density point clouds, thus demonstrating its great potential for delivering high-precision products with a spatial resolution of centimetres. The questions is, how should it be applied to obtain the best results? This research explores different flat scenarios to analyse the accuracy of this type of survey based on photogrammetric SfM (structure from motion) technology, flight planning with ground control points (GCPs), and the combination of forward and cross strips, up to the point of processing. The RMSE (root mean square error) is analysed for each scenario to verify the quality of the results. An equation is adjusted to estimate the a priori accuracy of the photogrammetric survey with digital sensors, identifying the best option for μ_xyz (weight coefficients depending on the layout of both the GCP and the image network) for the four scenarios studied. The UAV flights were made in Lorca (Murcia, Spain). The study area has an extension of 80 ha, which was divided into four blocks. The GCPs and checkpoints (ChPs) were measured using dual-frequency GNSS (global navigation satellite system), with a tripod and centring system on the mark at the indicated point. The photographs were post-processed using the Agisoft Metashape Professional software (64 bits). The flights were made with two multirotor UAVs, a Phantom 3 Professional and an Inspire 2, with a Zenmuse X5S camera. We verify the influence by including additional forward and/or cross strips combined with four GCPs in the corners, plus one additional GCP in the centre, in order to obtain better photogrammetric adjustments based on the preliminary flight planning.

【 授权许可】

Unknown