• Title/Summary/Keyword: Pixel purity index (PPI)

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Application of Spectral Mixture Analysis to Geological Mapping using LANDSAT 7 ETM+ and ASTER Images: Mineral Potential Mapping of Mongolian Plateau

  • Kim Seung Tae;Lee Kiwon
    • Proceedings of the KSRS Conference
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    • 2004.10a
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    • pp.425-427
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    • 2004
  • Motivation of this study is based on these two aspects: geologic uses of ASTER and application scheme of Spectral Mixture Analysis. This study aims at geologic mapping for mineral exploration using ASTER and LANDSAT 7 ETM+ at Mongolian plateau region by SMA. After basic pre-processing such as the normalization, geometric corrections and calibration of reflectance, related to endmembers selection and spectral signature deviation, both methods using spectral library and using PPI(Pixel Purity Index) are performed and compared on a given task. Based on these schemes, SMA is performed using LANDSAT 7 ETM+ and ASTER image. As the results, fraction map showing geologic rock types are enough to meet purposes such as geologic mapping and mineral potential mapping in the case of both uses of these different types of remotely sensed images. It concluded that this approach based on SMA with LANDSAT and ASTER is regarded as one of effective schemes for geologic remote sensing.

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Estimating Chlorophyll-a Concentration using Spectral Mixture Analysis from RapidEye Imagery in Nak-dong River Basin (RapidEye영상과 선형분광혼합화소분석 기법을 이용한 낙동강 유역의 클로로필-a 농도 추정)

  • Lee, Hyuk;Nam, Gibeom;Kang, Taegu;Yoon, Seungjoon
    • Journal of Korean Society on Water Environment
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    • v.30 no.3
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    • pp.329-339
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    • 2014
  • This study aims to estimate chlorophyll-a concentration in rivers using multi-spectral RapidEye imagery and Spectral Mixture Analysis (SMA) and assess the applicability of SMA for multi-temporal imagery analysis. Comparison between images (acquired on Oct. and Nov., 2013) predicted and ground reference chlorophyll-a concentration showed significant performance statistically with determination coefficients of 0.49 and 0.51, respectively. Two band (Red-RE) model for the October and November 2013 RapidEye images showed low performance with coefficient of determinations ($R^2$) of 0.26 and 0.16, respectively. Also Three band (Red-RE-NIR) model showed different performance with $R^2$ of 0.016 and 0.304, respectively. SMA derived Chlorophyll-a concentrations showed relatively higher accuracy than band ratio models based values. SMA was the most appropriate method to calculate Chlorophyll-a concentration using images which were acquired on period of low Chlorophyll-a concentrations. The results of SMA for multi-temporal imagery showed low performance because of the spatio-temporal variation of each end members. This approach provides the potential of providing a cost effective method of monitoring river water quality and management using multi-spectral imagery. In addition, the calculated Chlorophyll-a concentrations using multi-spectral RapidEye imagery can be applied to water quality modeling, enhancing the predicting accuracy.