CMASK

BDC acquires CBERS-4 Surface Reflectance Image Collections containing a cloud mask called Cmask. Cmask uses 3 different pixel values to map Clear, a Cloud or No data pixels. For CBERS-4 Data Cubes the CMASK band is generated by compositing the existent Image Collection CMASK bands. In BDC CBERS-4 products these values are remapped to the same as other BDC products, as can be seen in the following Table:

CMASK
Class	Pixel value
Clear Pixel	127
Cloud	255
No Data	0

For a description on CMASK see: SILVA, Marco Aurélio Oliveira; LIPORACE, Frederico dos Santos. DETECÇÃO AUTOMÁTICA DE NUVEM E SOMBRA DE NUVEM EM IMAGENS DE SENSORIAMENTO REMOTO. Bulletin of Geodetic Sciences, v. 22, n. 2, june 2016. ISSN 1982-2170. Available at: <https://revistas.ufpr.br/bcg/article/view/47507>.