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Sirvi Autor "Santos, L.M.D." järgi

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  • Pisipilt
    Kirje
    Analysis of flight parameters and georeferencing of images with different control points obtained by RPA
    (2019) Santos, L.M.D.; Ferraz, G.A.S.; Andrade, M.T.; Santana, L.S.; Barbosa, B.D.S.; Maciel, D.T.; Rossi, Giuseppe
    New techniques for analysing the earth's surface have been explored, such as the use of remotely piloted aircraft (RPA) to obtain aerial images. However, one of the obstacles of photogrammetry is the reliability of the scenes, because in some cases, considerable geometric errors are generated, thus necessitating adjustments. Some parameters used in these adjustments are image overlaps and control points, which generate uncertainties about the amount and arrangement of these points in an area. The aim of this study was to test the potential of a commercial RPA for monitoring and its applicability in the management of and decision-making about coffee crops with two different overlaps and to evaluate geometric errors by applying four grids of georeferenced points. The study area is located in an experimental Arabica coffee plantation measuring 0.65 ha. To capture the images, the flight altitude was standardized to a 30 m altitude from the ground, and a constant travel speed of 3 m s -1 was used. The treatments studied were two combinations of image overlap, namely, 80/80% and 70/60%. Six points were tracked through Global Navigation Satellite System (GNSS) receivers and identified with signs, followed by an RPA flight for image collection. The obtained results indicated distinct residual error rates pointing to larger errors along Cartesian axis Y, demonstrating that the point distribution directly affects the residual errors. The use of control points is necessary for image adjustments, but to optimize their application, it is necessary to consider the shape of the area to be studied and to distribute the points in a non-biased way relative to the coordinate axes. It is concluded that the lower overlap can be recommended for use in the flight plan due to the high resolution of the orthomosaic and the shorter processing time.
  • Pisipilt
    Kirje
    Spatial and temporal variability of enthalpy and its influence on the cloacal temperature of broilers
    (Estonian University of Life Sciences, 2024) Silva, M.A.J.G.; Santos, L.M.D.; Ribeiro, J.C.D.; Barbari, M.; Becciolini, V.; Naves, L.P.; Ferraz, P.F.P.
    Strategies aimed at mitigating heat stress conditions pose a challenge for the poultry industry operating in tropical climate zones. The primary aim of this research was to characterize and analyze the specific enthalpy of air (h, in kJ kg of dry air−1) in a broiler house using geostatistical techniques. In addition, its relationship with the cloacal temperature (tcloacal, °C) of the broilers was evaluated. The study was carried out in Lavras, Minas Gerais, Brazil. A total of 720 Cobb-500 broilers were raised from 1 to 42 days old. When the broilers were 7, 21, 35 and 42 days old, the dry bulb temperature (tdb, °C) and relative air humidity (RH, %) were recorded at 08:00 a.m. and 01:00 p.m. by seven sensors distributed throughout the installation, and tcloacal measured. Subsequently, h computed, and the data were examined through kriging interpolation. The tcloacal data were superimposed on the h maps of the facility. The spatial distribution of h inside the aviary (box) and temporal distribution (time and days) were characterized, and its variability was visualized. Tcloacal was directly related to the spatial as well temporal distribution of h, providing information about the thermal influence on production environment and the physiological responses of broilers.