IBGE releases mosaic of satellite images of Ceará
June 26, 2014 09h00 AM | Last Updated: February 22, 2018 01h03 PM
IBGE releases today, June 26, 2014, images of Ceará in its web portal. Ortho-rectified and mosaicked, the images were obtained from the AVNIR-2 sensor of the ALOS satellite.
The individual ortho-rectified images, released in 2013, and the 1:100,000 maps of the ortho-mosaics, released today, are available in GeoTIFF format in the IBGE web page through link
ftp://geoftp.ibge.gov.br/imagens_do_territorio/imagens_corrigidas/ortomosaicos/bc100/
More information on this product can be obtained on link
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Collection is part of BC100 project
The collection of available images is part of the "1:100,000 Cartographic Base - BC100" project, aimed at providing the society with ortho-rectified images, ortho-mosaics and image-maps of some Federation Units. The project is designed to address the demand for up-to-date information, compatible with the scale of 1:100,000 (1cm = 1km).
The ortho-rectified images underwent a correction process in relation to a number of geometric distortions, caused by factors like image angle, relief, Earth curvature and Earth rotation. The mosaicking process gathers a number of ortho-rectified AVNIR-2 scenes, which are cut and mounted to cover all the area corresponding to a single topographic map.
The collection now available includes images covering 88% of Ceará. In the other areas of the state, the images showed a high percentage of clouds, thus hiding the territory. As a result, neither ortho-rectified images nor ortho-mosaics were generated. Planning is underway to use images from another sensor to cover the remaining 12% of the state not covered by AVNIR-2 images.
Satellite images show 10 m of spatial resolution
The AVNIR-2 sensor produces images with 10-meter spatial resolution in four spectrum bands, corresponding to blue, green, red and near infrared. The images used in the project were acquired between 2006 and 2010, the majority of them in 2009 and 2010.