Evaluation of Digital Classification of Polarimetric SAR Data for Iron-Mineralized Laterites Mapping in the Amazon Region

Remote Sensing

Arnaldo de Q. da Silva²  Waldir R. Paradella¹  Corina C. Freitas¹ 

[1] National Institute for Space Research (INPE), Av. dos Astronautas, 1758-Jardim da Granja, Caixa Postal 515, São José dos Campos-SP, 12227-010, Brazil; E-Mails:;Institute of Geoscience, Federal University of Pará (UFPA), Rua Augusto Corrêa, 01-Guamá, Caixa postal 479, Belém-PA, 66075-110, Brazil

关键词: polarimetric SAR;    digital classification;    geology/laterites mapping;    Carajás Province;   

DOI  :  10.3390/rs5063101

来源: mdpi

【 摘 要 】

This study evaluates the potential of C- and L-band polarimetric SAR data for the discrimination of iron-mineralized laterites in the Brazilian Amazon region. The study area is the N1 plateau located on the northern border of the Carajás Mineral Province, the most important Brazilian mineral province which has numerous mineral deposits, particularly the world’s largest iron deposits. The plateau is covered by low-density savanna-type vegetation (campus rupestres) which contrasts visibly with the dense equatorial forest. The laterites are subdivided into three units: chemical crust, iron-ore duricrust, and hematite, of which only the latter two are of economic interest. Full polarimetric data from the airborne R99B sensor of the SIVAM/CENSIPAM (L-band) system and the RADARSAT-2 satellite (C-band) were evaluated. The study focused on an assessment of distinct schemes for digital classification based on decomposition theory and hybrid approach, which incorporates statistical analysis as input data derived from the target decomposition modeling. The results indicated that the polarimetric classifications presented a poor performance, with global Kappa values below 0.20. The accuracy for the identification of units of economic interest varied from 55% to 89%, albeit with high commission error values. In addition, the results using L-band were considered superior compared to C-band, which suggest that the roughness scale for laterite discrimination in the area is nearer to L than to C-band.

【 授权许可】

CC BY   
© 2013 by the authors; licensee MDPI, Basel, Switzerland