Abstract

SILVA JUNIOR, Juarez Antônio da; FRANCA, Thaisa Manoela Silva  and  MORAES, Vanessa Silva de. Evaluation of planimetric accuracy of Google images Earth in an urban and rural area in the State of Pernambuco, Brazil. Rev. cartogr. [online]. 2022, n.105, pp.117-133.  Epub Oct 10, 2022. ISSN 2663-3981.  https://doi.org/10.35424/rcarto.i105.1386.

Due to the popularity of Google Earth, users often use the platform's geographic data for scientific and spatial planning purposes. However, Google claims that these data are only approximations and therefore their positional accuracy is not officially documented. In view of the improvement in obtaining these data, there is a need to assess the quality of the cartographic product. Thus, this work aims to evaluate the planimetric quality of point data obtained from Google Earth, based on Descriptive Statistics, Trend Analysis and the Brazilian Standard for Cartographic Precision (PEC-PCD). For this, two georeferenced orthophotos with a spatial resolution of 5 cm were used as a reference, one in an urban area and another in a rural area in the state of Pernambuco, Brazil. In the results, a positional error of 1.26 m was found in the urban area and 4.65 m in the rural area. According to the PEC-PCD analysis, the planimetric data generated by Google Earth meet the technical specifications at scales of less than 1:5000, in densely urbanized areas, and 1:10,000, in non-urbanized areas. Thus, in places with greater availability of high resolution satellite images, it was observed that the data present a more significant precision. In this sense, Google Earth represents an attractive source of positional data that can be used for spatial analysis and preliminary surveys.

Keywords : Google Earth; positional accuracy; Brazilian Standard for Cartographic Precision (PEC-PCD); Pernambuco.

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