DOI: 10.5281/zenodo.5786510
title: The MANVI product: MODIS (MAIAC) nadir-solar adjusted vegetation indices (EVI and NDVI) for South America

description: <strong>Title: </strong>The MANVI product: MODIS (MAIAC) nadir-solar adjusted vegetation indices (EVI and NDVI) for South America. <strong>Authors:</strong> Dalagnol, Ricardo; Wagner, Fabien Hubert; Galvão, Lênio Soares; Aragão, Luiz Eduardo Oliveira e Cruz. <strong>Contact:</strong> Ricardo Dalagnol (ricds@hotmail.com) <strong>27 Jan 2022 - MANVI v2 was released!</strong> All data were reprocessed and improved. It is advised to re-download the whole series instead of combining v1 and v2. The dataset now covers years 2000-2021. <strong>23 May 2019 - MANVI v1 was released.</strong> It covers years 2000-2018. <strong>Data:</strong> MODIS (MAIAC) EVI and NDVI indices <strong>Scale factor</strong>: 10000 <strong>Coverage:</strong> South America land <strong>Time period:</strong> 2000 to 2021 (starting in 2000, Julian day 64) <strong>Spatial resolution:</strong> 1 km <strong>Temporal resolution:</strong> 16 days <strong>Coordinate reference system:</strong> geographic projection, datum WGS-84 <strong>Processing details:</strong> The original MODIS (MAIAC) data were described by Lyasputin et al. 2011 (https://doi.org/10.1029/2010JD014986). The daily MODIS (MAIAC) surface reflectance data from collection 6, acquired from Terra and Aqua satellites, are available from the MCD19A1 product (https://ladsweb.modaps.eosdis.nasa.gov/archive/allData/6/MCD19A1). The Bidirectional Reflectance Distribution Function (BRDF) model parameters are available from MCD19A3 product (https://ladsweb.modaps.eosdis.nasa.gov/archive/allData/6/MCD19A3) The daily MCD19A1 data at 1 km spatial resolution were normalized using the BRDF parameters and Ross-Thick Li-Sparse (RTLS) model considering a fixed nadir view and a 45 deg. solar zenith angle using the parameters from the MCD19A3 product The daily data were aggregated into 16-day composites by the pixel’s median. The 16-day composites always start from Day Of Year (DOY) 016 and end with DOY 352. Therefore, the remaining days from 352 to 365/366 were not used. This procedure was used to facilitate inter-annual comparisons The tiles that cover the South America were mosaicked and re-projected from sinusoidal to geographic projection The Normalized Difference Vegetation Index (NDVI) and Enhanced Vegetation Index (EVI) were calculated using standard formulas. The EVI parameters were: C1 = 6, C2 = 7.5, L = 1, G = 2.5 <strong>File(s) format:</strong> Zip files for EVI and NDVI - one per year: Inside them there are raster files with ".tif" format, one per 16-day window. The filename syntax is "maiac_southamerica_DATA_YYYYDOY.tif", where YYYY is the year (e.g. 2000), and the DOY is the Julian day of the last day of the composite window, i.e. YYYYDOY for January 2005 for DOY from 001 to 016 is 2005016, from DOY 017 to 032 is 2005032, etc. Csv files with the YYYYDOY and "real" dates for the time period <strong>Code:</strong> https://github.com/ricds/maiac_processing <strong>Acknowledgements:</strong> This work was funded by São Paulo Research Foundation – FAPESP, Brazil, grant 2015/22987-7. We thank NASA, and especially Yujie Wang and Alexei Lyapustin, for providing the freely available MODIS (MAIAC) data. <strong>Dataset usage</strong>: This dataset is a product of the first author's PhD work and lots of hours of coding and patience. It is free to use, but if you use this dataset in your work, please make sure to properly cite the repository. We also welcome users to invite us for collaboration. <strong>For use of this dataset please cite:</strong> Dalagnol, Ricardo; Wagner, Fabien Hubert; Galvão, Lênio Soares; Aragão, Luiz Eduardo Oliveira e Cruz. (2022). "The MANVI product: MODIS (MAIAC) nadir-solar adjusted vegetation indices (EVI and NDVI) for South America". (Version v2) [Data set]. Zenodo. https://doi.org/10.5281/zenodo.3159487 <strong>More information: </strong>contact Ricardo Dalagnol (ricds@hotmail.com). We also have the MODIS (MAIAC) BRDF-corrected bands 1-8, EVI, NDVI at 1 km with 16-day and monthly aggregation composites.
description: {"references": ["https://doi.org/10.5194/bg-15-6087-2018"]}