Innovative Terrain Mapping: A Comparison of Drone and iPhone + viDoc Techniques

Abstract—This study presents a comparison of two different surveying methodologies aimed at terrain modeling. The first approach involved a drone equipped with multispectral sensors, while the second utilized an iPhone combined with the viDoc RTK Rover for data acquisition, which enables the creation of high-accuracy 3D models by generating geo-referenced images in real time. The comparison was possible thanks to precise georeferencing, achieved by performing NRTK (Network Real Time Kinematic) surveys of control points placed near the area of interest and visible in both drone and iPhone-acquired images. The difference between the two-point clouds was evaluated by performing point-to-point distance comparisons, while digital elevation models (DEMs) were compared in a GIS environment using pixel-by-pixel subtraction. The analysis revealed that the differences in point positions between the two surveys were within a few centimeters, with variations primarily attributed to sensor and environmental factors. Similarly, the elevation differences between the DEMs were also in the centimeter range, indicating high precision in both methods. These findings demonstrate that both technologies can provide accurate terrain models, with minor differences that are typically within the acceptable range for many precision agriculture and land management applications. The results underscore the strengths and limitations of each technology, offering insights into their practical applicability for field surveying.