Uncovering the hidden: Leveraging sub-pixel spectral diversity to estimate plant diversity from space
Christian Rossi, Oklahoma State University, christian.rossi@nationalpark.ch
Hamed Gholizadeh, Oklahoma State University, hamed.gholizadeh@okstate.edu (Presenter)
Remotely sensed spectral diversity has emerged as a promising proxy for plant diversity. However, traditional spectral diversity approaches consider each pixel as a homogeneous entity composed of one class and disregard the within-pixel variability. Although this assumption might hold true for remotely-sensed data with fine spatial resolution, it might not be valid for forthcoming coarse-resolution spaceborne imagers with spatial resolution of approximately 30 m. The coarse spatial resolution of spaceborne imagers is a major limitation to successfully estimating plant diversity. To address the limitations associated with the coarse spatial resolution of spaceborne imagers, we proposed a novel approach, known as endmember diversity, for remote estimation of plant diversity through quantifying spectral diversity at the sub-pixel level and taking into account the within-pixel variability. The approach consisted of deriving the number and abundance of unique spectral entities within each pixel via spectral unmixing. In doing so, we considered the spectral signature of each pixel as a mixture of unique spectral entities, commonly known as endmembers. We then used the per-pixel endmembers and their abundance to calculate different spectral diversity metrics for every pixel. We assessed the performance of the endmember diversity approach at estimating plant taxonomic and phylogenetic diversity based on two experiments using a simulated spectral dataset and a real-world spaceborne DESIS (DLR Earth Sensing Imaging Spectrometer) dataset. In both experiments, we found significant associations between endmember diversity and in-situ plant diversity. Additionally, our method outperformed commonly-used spectral diversity metrics based on the coefficient of variation when applied to 1-m airborne imaging spectroscopy data. Collectively, our results demonstrate the capability of forthcoming spaceborne imagers to monitor local plant diversity.
Poster: Poster_Rossi_2-40_231_35.pdf
Associated Project(s):
Poster Location ID: 2-40
Presentation Type: Poster
Session: Poster Session 2
Session Date: Wed (May 10) 5:15-7:15 PM
CCE Program: BDEC