Title
Model-Based Optimization of Spectral Sampling for the Retrieval of Crop Variables with the PROSAIL Model.
Abstract
Satellite hyperspectral Earth observation missions have strong potential to support sustainable agriculture by providing accurate spatial and temporal information of important vegetation biophysical and biochemical variables. To meet this goal, possible error sources in the modelling approaches should be minimized. Thus, first of all, the capability of a model to reproduce the measured spectral signals has to be tested before applying any retrieval algorithm. For an exemplary demonstration, the coupled PROSPECT-D and SAIL radiative transfer models (PROSAIL) were employed to emulate the setup of future hyperspectral sensors in the visible and near-infrared (VNIR) spectral regions with a 6.5 nm spectral sampling distance. Model uncertainties were determined to subsequently exclude those wavelengths with the highest mean absolute error (MAE) between model simulation and spectral measurement. The largest mismatch could be found in the green visible and red edge regions, which can be explained by complex interactions of several biochemical and structural variables in these spectral domains. For leaf area index (LAI, m(2)m(-2)) retrieval, results indicated only a small improvement when using optimized spectral samplings. However, a significant increase in accuracy for leaf chlorophyll content (LCC, mu gcm(-2)) estimations could be obtained, with the relative root mean square error (RMSE) decreasing from 26% (full VNIR range) to 15% (optimized VNIR) for maize and from 77% to 29% for soybean, respectively. We therefore recommend applying a specific model-error threshold (MAE of similar to 0.01) to stabilize the retrieval of crop biochemical variables.
Year
DOI
Venue
2018
10.3390/rs10122063
REMOTE SENSING
Keywords
Field
DocType
PROSAIL,LAI,leaf chlorophyll content,radiative transfer model,imaging spectroscopy,hyperspectral missions,feature selection,optimized spectral sampling
Leaf area index,VNIR,Remote sensing,Mean squared error,Hyperspectral imaging,Sampling (statistics),Earth observation,Geology,Radiative transfer,Red edge
Journal
Volume
Issue
Citations 
10
12
0
PageRank 
References 
Authors
0.34
13
6
Name
Order
Citations
PageRank
Katja Berger1206.19
Clement Atzberger255755.26
Martin Danner3182.70
Matthias Wocher471.88
Wolfram Mauser523335.12
Tobias Hank65411.02