Analysis of flight parameters and georeferencing of images with different control points obtained by RPA
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Kuupäev
2019
Kättesaadav alates
Autorid
Santos, L.M.D.
Ferraz, G.A.S.
Andrade, M.T.
Santana, L.S.
Barbosa, B.D.S.
Maciel, D.T.
Rossi, Giuseppe
Ajakirja pealkiri
Ajakirja ISSN
Köite pealkiri
Kirjastaja
Abstrakt
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.
Kirjeldus
Article
Märksõnad
orthorectification of images, geometric error, photogrammetry, UAS (Unmanned Aircraft System), overlap, articles