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The Successive Projection Algorithm (SPA), an Algorithm with a Spatial Constraint for the Automatic Search of
Jinkai Zhang1, Benoit Rivard2, D M Rogge3
1Alberta Terrestrial Imaging Center, 401, 817 - 4th Avenue South, Lethbridge, Alberta Canada, T1J 0P3. benoit.rivard@ualberta.ca.
Sensors (Basel, Switzerland)
|November 24, 2016
Summary
The Successive Projection Algorithm (SPA) improves remote sensing by using spatial adjacency to find realistic spectral endmembers, reducing outlier susceptibility. This method enhances hyperspectral data analysis without dimensionality reduction.
Area of Science:
- Remote Sensing
- Geospatial Analysis
- Spectral Imaging
Background:
- Spectral mixing in remote sensing data leads to pixels representing multiple materials, complicating analysis.
- Linear spectral mixture analysis assumes pixel variability arises from differing proportions of spectral endmembers.
- Existing endmember-search algorithms often rely on convex geometry and orthogonal projection.
Purpose of the Study:
- Introduce a novel endmember-search algorithm, the Successive Projection Algorithm (SPA).
- Address the limitations of existing methods by incorporating spatial constraints.
- Improve the accuracy and reliability of endmember extraction from hyperspectral data.
Main Methods:
- Developed the Successive Projection Algorithm (SPA), incorporating spatial adjacency of endmember candidate pixels.
- Utilized spectral angle and spatial continuity to constrain endmember selection.
- Applied SPA to AVIRIS Cuprite and Probe-1 hyperspectral imagery for validation.
Main Results:
- SPA successfully extracts endmembers from hyperspectral data without dimensionality reduction.
- The algorithm demonstrates reduced susceptibility to outlier pixels, generating more realistic endmembers.
- Case studies validated SPA-derived endmembers against ground truth data.
- SPA provides data on simplex volume ratio changes, indicating convergence and aiding in determining the number of endmembers.
Conclusions:
- The Successive Projection Algorithm (SPA) offers a robust method for endmember extraction in hyperspectral remote sensing.
- Incorporating spatial adjacency significantly enhances the reliability and realism of extracted endmembers.
- SPA's ability to operate without dimensionality reduction and provide convergence insights makes it a valuable tool for geospatial analysis.
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