Fractional cover - MODIS, CSIRO algorithm
Vegetation Fractional Cover represents the exposed proportion of Photosynthetic Vegetation (PV), Non-Photosynthetic Vegetation (NPV) and Bare Soil (BS) within each pixel. The sum of the three fractions is 100% (+/- 3%) and shown in Red/Green/Blue colors. In forested canopies the photosynthetic or non-photosynthetic portions of trees may obscure tho... morese of the grass layer and/or bare soil. This product is derived from the MODIS Nadir BRDF-Adjusted Reflectance product (MCD43A4) collection 6 and has 500 meters spatial resolution.
A suite of derivative products are also produced including monthly fractional cover, total vegetation cover (PV+NPV), and anomaly of total cover against the time series.
Monthly: The monthly product is aggregated from the 8-day composites using the medoid method.
Anomaly: represents the difference between total vegetation cover (PV+NPV) in a given month and the mean total vegetation cover for that month in all years available, expressed in units of cover. For example, if the mean vegetation cover in January (2001-current year) was 40% and the vegetation cover for the pixel in January 2018 was 30%, the anomaly for the pixel in Jan 2018 would be -10%.
Decile: represents the ranking (in ten value intervals) for the total vegetation cover in a given month in relation to the vegetation cover in that month for all years in the time-series.
MODIS fractional cover has been validated for Australia. less
Agricultural Land Management
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Conservation and Biodiversity
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Ecological Applications not elsewhere classified
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Environmental Monitoring
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Land Capability and Soil Degradation
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Landscape Ecology
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Natural Resource Management
01 Jan 2001
11 Nov 2019
Juan Guerschman
Juan.Guerschman@csiro.au
Vegetation cover
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vegetation area fraction
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MODIS
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fractional cover
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ground cover
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total cover
Version 3.0: Fractional cover was derived using a linear unmixing methodology (Guerschman et al. 2015). The method uses all 7 MODIS bands and adds log transforms and band interaction terms to account for non-linearities in the spectral mixing. A cross-validation step was also included to select the optimal number of singular values to avoid over-fitting. The calibration and validation steps used 1171 field observations across Australia. Overall, the model fitted and applied to MCD43A4 fractional cover has a root mean square error (RMSE) of 12.9%, 18.1% and 16.6% for the PV, NPV and BS fractions respectively (percentage cover)
Version 3.1: ("v310") Same as Version 3.0 with the following modifications: 1- input data changed to MODIS Collection 6.0 (MCD43A4.006) (see source). 2- calibration dataset expanded to include ~3022 field measurement sites accross Australia. 3- overall accuracy improved to an RMSE of 11.3%, 16.1% and 14.7% for the PV, NPV and BS fractions respectively.
Monthly vegetation cover is calculated from the 8-day composites using a medoid method as described in Gill et al.
Monthly anomalies show the difference between total vegetation cover (PV+NPV) in a given month and the mean total vegetation cover for that month in all years available\nMonthly deciles show the decile (ranking) for the total vegetation cover in a given month in relation to the vegetation cover in that month for all years in the time series.
This dataset has been developed by the Environmental Earth Observation Group, CSIRO Land and Water.
Creative Commons Attribution 4.0 International Licence
CSIRO (Australia), Terrestrial Ecosystem Research Network (TERN) (Australia), Australian Government Department of Agriculture (Australia)
Guerschman, Juan (2014): Fractional cover - MODIS, CSIRO algorithm. v2. CSIRO. Data Collection. 102.100.100/42094
All Rights (including copyright) CSIRO 2014.
The metadata and files (if any) are available to the public.
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