# Suitability of Aerial Photogrammetry for Dump Documentation and Volume Determination in Large Areas
## 1 Introduction  
In industrial plants, such as mining and metallurgical plants, there is a frequent requirement for the periodical quantification of the amount of materials stored in the input or waste dumps. The stored material usually consists of a loose consistency gravel, sand, iron ore pellets, steelmaking slag, gangue, fly ash, etc. Given the logistics of the production process, the materials entering into production usually have a heap shape. Materials of different kinds or fractions are stored in separate heaps. Material loading and removal occur in small heaps realized by tracked or wheeled loaders; at larger scale heaps, a belt or giant gantry machines are preferably used. A required quantification parameter is the volume of the deposited material in the desired moment. The methodology of the work consists of geodetic measurements in the field, data processing, and calculation. When choosing a surveying method, it is essential to consider the specific size and shape of the measured object, its accessibility in terms of personnel safety while surveying, and the time period in which it is necessary to make measurements in the field [1]. An important aspect is the required accuracy of the determined volume, which depends mainly on the precision and detail of the resultant 3D model, i.e., primarily the amount and precision of measured points [2]. Several geodetic methods can be used for this purpose. Global navigation satellite systems (GNSS) and the real-time kinematics method (RTK) are suitable for such works. The tachymetric measurement on the principle of the spatial polar method using electronic total station (TS) can be considered as a base method for geodetic spatial data collection [3]. The non-prism distance measurement use is suitable for detailed point measurements of minimal personnel movement on the heap body and accelerating fieldworks [3]. The motorized total stations with automatic scanning option and mainly terrestrial laser scanners (TLS) are the current trend of spatial polar method use in surveying instruments [4]. These surveying technologies are most commonly used for direct spatial data collection. Their advantage is simplicity with appropriate accuracy; the disadvantage is mainly the long time period required to carry out measurements in the field, often in dangerous conditions on the bulk material. The TLS measurement method has been used as a validated and reference method for comparing the results of several tested measurement methods and for evaluating surfaces in high-altitude environments [5; 6]. [PERSON] et al. [7], [PERSON] et al. [8], and [PERSON] et al. [9] also used TLS measurements in the mapping of underground and surface karst areas. [PERSON] et al. [10] used TLS measurements to determine the deformation of a bridge and to document the facade elements of a high-rise building. They used a high scan point density of 3 mm to capture small-scale details on the measured object. In [11], the TLS method was used as a reference in the investigation of the spatial deformation of a bridge. TLS measurement can be used in an industrial environment to document industrial machinery, such as rotary kilns [12] and boiler drums [13]. Another use is the ability to accurately determine the volumes of mined reserves and determine the specific gravity of heterogeneous materials [14]. [PERSON] used high-density terrestrial laser scanning in the documentation of historical monuments [15; 16], and [PERSON] [17] and [PERSON] [18] combine TLS and SfM photogrammetry. We consider aerial photogrammetry (AP) as a traditional surveying method. Compared to the aforementioned methods, it is suitable for larger territorial unit mapping or larger object documentation [19]. The most common products of aerial image processing are vector maps, orthophoto maps, digital terrain models (DTM), and digital surface models (DSM) [20; 21; 22].