Creation of high-precision digital elevation models using the GNSS UAV

Abstract

Unmanned Aerial Vehicles (UAVs) are increasingly involved in surveying work, becoming a reliable basis for information on three-dimensional terrain features. Until now, ground reference points have been used to provide reliable planimetric evidence for measurements from drones. Their placement and coordinates measurement takes quite a long time, which increases proportionally to the area under study. In addition, the use of these marks produces model distortions (especially over large areas of 1 sq. km or more), which then lead to the appearance of areas of local depressions and uplifts where they are not present in the terrain. These distortions arise due to camera position optimization error minimization algorithms and cannot be corrected. Refusing to use ground control points leads to other geometric distortions associated with characteristics of survey system lenses mounted on UAVs (so-called “saddle-shaped” models). This paper presents the results of high-precision digital elevation models creation using built-in UAV Global Navigation Satellite System (GNSS) receivers. The methodology has been tested at ten sites in the Zakamye region of the Republic of Tatarstan (Russia) with an area ranging from 4 to 58 hectares. Correction of GNSS rover position was performed in post-processing from a virtual base station network located at a 6 to 70 km range from the surveyed sites. For all objects, DEM errors did not exceed 0.05 m on axes X, Y, and Z. At the same time, the dependence of the error value on the study area size was not revealed. The received results of the analysis of errors can indicate the prospect of the use of low-cost GNSS-UAVs without the necessity of organizing a network of ground reference points, being limited only to the necessity of installing control points will repeatedly reduce the time of the field works, in particular on hardly accessible objects.

Monitoring the filling of the landfill using the results of aerial photography

“…The original method of referencing is used in the work. The method allows to correlate the design and actual values by finding common points on the initial relief at the project schemes, and DTM, built by the results of modern field research [18]. After transforming the data into a single coordinate system, it becomes possible to estimate the degree of filling of the polygon and its residual capacity (Figure 2).…”

Remote Sensing Monitoring on the Territory of the Volga Carbon Polygon (Republic of Tatarstan, Russia)

“…During the first year of data collection, orthophotomaps and DEMs were obtained for both polygon sections, and a digital model of the relief of the water section of the carbon polygon was constructed. The problem of construction of a high-resolution model of the relief in the forested areas can be solved using airborne laser scanning [21,35]. For this purpose, in 2023 an aerial lidar survey performed by AGM MS-1 laser scanner which allows surveying with 600000 points per second from 120-200 m altitudes.…”

“…Unlike satellite data, the UAV allows to survey and obtains cloudless data with the required periodicity, and creates time-series for further analysis [35]. Initially, based on the results of the UAV survey with a Sony RX1R2 camera in the visible wave range, high-resolution orthophotomaps were obtained (Figure 4 a).…”

Uav Aerial Survey in Monitoring of Coastal Geosystems in the Southern Irkutsk Amphitheatre

“…В различных областях научной и производственной деятельности широко используются беспилотные летательные аппараты (БПЛА) [Makarov, 2018;Rybchenko et al, 2019;Kolesatova, Krasavin, 2020;Alexeev et al, 2022;Lunina, Gladkov, 2022;Filice et al, 2022;Lunina et al, 2023;многие другие]. Имеющиеся литературные данные касаются сравнительной оценки точности моделей рельефа, получаемых с помощью БПЛА аэрофотосъемки в сочетании с лазерным сканированием, лидарной, тахеометрической съемками [Gafurov, 2017;Elsner et al, 2018;Gafurov et al, 2021].…”

“…Кроме того, исследованиями [Gafurov et al, 2021] доказана высокая точность и корректность цифровых моделей высот (ЦМВ), построенных по результатам съемки с помощью ГНСС-БПЛА, для тестовых участков лесостепной территории Закамья Республики Татарстан. Погрешности ЦМВ находятся в пределах допустимых отклонений (согласно ГОСТ Р 58854-2020) и не превышают 5 см по осям X, Y, Z.…”