An unmanned aerial vehicle (UAV) is remotely guided aerial vehicle that is capable of carrying manual or automated flight missions and data acquisition. UAV can be combined with various other devices for data acquisition, e.g. LiDAR, DSLR cameras, thermal cameras, multi-spectral cameras, etc. UAV capable of aerophotogrametric imaging is needed for accomplishing the set objectives and the activities proposed in this project. The UAV will be used in almost all the proposed researches for imaging a wide research area and the creation of a digital ortho photo image (DOF) and of digital surface models (DSMs). The UAV will have an especially important role in researching gullies where it will be used to periodically image the wider area of the selected gullies and the creation of digital relief models that will be needed for researching the features of drainage area of a gully and surface outflow of rainfall into a gully. Combined with a multispectral and a thermal camera, the UAV will be used in precise agriculture through monitoring of vegetation health (NDVI index), soil moisture, etc.
VELODYNE LiDAR PUCK LITE
In the field of surface geomorphological and archaeological research, the technology of air laser scanning is a great support since it provides a digital terrain model. The laser beam sent from the ceiling measures the land elevation by penetrating the area vegetation cover. The digital terrain model is highly accurate and detailed, thus the areas that were previously inaccessible or difficult to register now can be the object of extensive research. Digital data recording about the actual natural topography allows to back up information and, gives the possibility of multiple analysis of the area.Data analysis using GIS (Geographic Information System) tools enables to probe the spatial relationships between the objects, microcomponents of land relief and shadow that is cast. It allows the scientists to examine the area from different perspectives and recognize the nuances of the terrain that are not visible from the perspective of an observer standing on the ground.
FARO FOCUS 3D LASER SCANNER
Terrestric laser scanner (TLS) is a high accuracy, short range scanner that delivers acquisition speed of almost 1,000,000 points per second, with accuracy of +/- 1mm. It enables the acquisition of data that are necessary to build models with very high resolution. With the scanning range up to 70 m from the TLS’s position this scanner is perfect for various indoor and outdoor tasks. Therefore, it is often used for architecture, engineering, construction, product design and public safety-forensics professionals. Within the GAL laboratory TLS will be used for acquisition of precise point clouds of study areas, that will allow creation of high-resolution digital elevation models (DEMs). Beside terrain modelling TLS will be applied in Archaeology for scanning and monitoring of archaeological sites, as well as in Precise Agriculture for tree-based analysis of olive groves.
REDEDGE-MX - MICASENSE
Spectral Bands: Blue, green, red, red edge, near-IR (global shutter, narrowband). Wavelength (nm): Blue (475 nm center, 20 nm bandwidth), green (560 nm center, 20 nm bandwidth), red (668 nm center, 10 nm bandwidth), red edge (717 nm center, 10 nm bandwidth), near-IR (840 nm center, 40 nm bandwidth). RGB Color Output: Global shutter, aligned with all bands. Ground Sample Distance (GSD): 8 cm per pixel (per band) at 120 m (~400 ft) AGL. A multispectral image is one that captures image data within specific wavelength ranges across the electromagnetic spectrum. The wavelengths may be separated by filters or by the use of instruments that are sensitive to particular wavelengths, including light from frequencies beyond the visible light range, i.e. infrared and ultra-violet. Spectral imaging can allow extraction of additional information the human eye fails to capture with its receptors for red, green and blue. It was originally developed for space-based imaging, and has also found use in document and painting analysis.
Most radiometers for remote sensing (RS) acquire multispectral images. Dividing the spectrum into many bands, multispectral is the opposite of panchromatic, which records only the total intensity of radiation falling on each pixel. Usually, Earth observation satellites have three or more radiometers. Each acquires one digital image (in remote sensing, called a 'scene') in a small spectral band. The bands are grouped into wavelength regions based on the origin of the light and the interests of the researchers.
CLOSE RANGE PHOTOGRAMMETRY
CRP has dispersive use and strong interdisciplinary character. In literature, there is no generally accepted classification of CRP. Among other things, it is stated that CRP is applied on objects measuring from 1 m to 200 m (Image 1), with precision under 0,1 mm on smaller objects (manufacturing industry) and 1 cm on larger objects (architecture and construction industry). Different types of cameras and platforms can be used while gathering shots in the process of CRP. Cameras can be installed on a drone or any other means of transport. The basic precondition of every successful work process of CRP is the gathering of high-quality photographs of objects, from which different models (DMP, DOF, 3D model, dense point cloud) are performed. “High-quality” images mark the term which describes images of equal exposition, high contrast, which are sharp and in which the object of shooting fills the entire space of the image. Process of data gathering, which includes shooting photographs and gathering of orientation points (GCP), is crucial if model of high quality is wanted.
Within the GAL project, the method of close-range photogrammetry will be applied in all activities which contain aerophotogrammetry shooting in the distance less than 300 m from shooting object. The method of close-range photogrammetry can, if needed, combine photographs shot by unmanned aerial vehicle and digital camera on the field. After the filtration and processing of the shots, high-resolution DMP, DOF and 3D models of selected area or object on a micro (cm) scale will be created. Therefore, method of close-range photogrammetry will be applied in all applicative researches defined within the working plan of the GAL project, which include:
1) Development of multi-criterion model of sustainable management in the area of tufa-forming flows
2) Development of new methodological approach in the study of ravines
3) Finding practical solutions through the application of geospatial analyses in archaeology and agronomy
Infra red thermography presents contactless method of temperature measurement by using infra red radiation, which collects temperature data of measured object or selected location. Otherwise, the area of infra red radiation can be divided into SWIR – Short Wave Infra Red, MWIR – Medium Wave Infra Red, LWIR – Long Wave Infra Red and VLW – Very Long Wave Infra Red. It is used for measuring temperature and its distribution on the surface of the observed object or surface. By applying appropriate cameras, measuring can be performed invasively, remotely, in real time, moving targets can be recorded, and the thermal balance of the recorded object is, therefore, not disturbed. Thermal or thermovision infra red cameras have very wide use in different scientific fields, economic activities (surveillance of area, security, medical diagnostics, agriculture, detection of anomalies in specific infrastructure). One of their advantages is that they enable measurement of dark, inaccessible and dangerous areas, and almost all sorts of material. Results themselves depend on more factors, the most important of them being: characteristics of objects or surface measured, temperature of environment and surrounding objects, distance and medium between an object and camera and mere attributes of the camera (resolution and sensitivity). Functional connection of 3D scanner and thermal cameras would enable obtaining 3D thermogram. Because of its wide use, it is currently very popular to install thermal cameras on unmanned aircraft vehicles (Image 3). One of most popular uses is support in fire extinguishing, because the system provides current image of an area regardless of smoke, and enables tracking the intervention team in large fire areas.
Within the GAL project, thermal camera will be applied within the project research 3) Finding practical solutions by applying geospatial analyses in archaeology and agronomy, where thermographic recordings will be applied in evaluating the quality of yields after harvest, in detection of water stress on olive plantations and in detection of drought in agricultural crops and irrigation planning.