Validation of the MODIS NDVI Products in Different Land-Use Types Using In Situ Measurements in the Heihe River Basin

An evaluation of the Moderate Resolution Imaging Spectroradiometer (MODIS) normalized difference vegetation index (NDVI) products is essential for their use in scientific studies. We evaluated the accuracy of MODIS NDVI data that were derived from the MOD09GQ and MYD09GQ products using ground-based measurements from nearly one complete growing season (from May 2 to September 28, 2013) for six land-use types in the upper and middle reaches of the Heihe River Basin. The spatial heterogeneity and scale effects of the NDVI were analyzed using TM8 images of the observation sites. A comparison of the field measurements showed that the MODIS NDVI data were correlated with the in situ data and had an R2 of 0.60-0.98. The semivariance analysis results showed that scale effects were common for MODIS data at a pixel resolution of 250 m for corn, potato, rape, and barley crops. Upscaling the in situ NDVI data using high spatial resolution satellite images can improve the validation accuracy of pixel-level NDVI. The results from this letter provide ground-based NDVI data that are required for the calibration and validation of satellite observations and products.

[1]  K. Soudani,et al.  Ground-based Network of NDVI measurements for tracking temporal dynamics of canopy structure and vegetation phenology in different biomes , 2012 .

[2]  Xiuji Zhou,et al.  Validation of the MODIS global land surface albedo product using ground measurements in a semidesert region on the Tibetan Plateau , 2004 .

[3]  Uwe Spank,et al.  Comparison of satellite- and ground-based NDVI above different land-use types , 2009 .

[4]  Wei Wei,et al.  Spatial scale conversion approach for moderate-resolution imaging spectroradiometer leaf area index product validation , 2013 .

[5]  A. Huete,et al.  A comparison of vegetation indices over a global set of TM images for EOS-MODIS , 1997 .

[6]  Qing Xiao,et al.  Heihe Watershed Allied Telemetry Experimental Research (HiWATER): Scientific Objectives and Experimental Design , 2013 .

[7]  Yann Nouvellon,et al.  MODIS NDVI time-series allow the monitoring of Eucalyptus plantation biomass , 2011 .

[8]  MODIS‐derived NDVI Characterisation of Drought‐Induced Evergreen Dieoff in Western North America , 2009 .

[9]  Alan H. Strahler,et al.  The Moderate Resolution Imaging Spectroradiometer (MODIS): land remote sensing for global change research , 1998, IEEE Trans. Geosci. Remote. Sens..

[10]  C. Justice,et al.  A framework for the validation of MODIS Land products , 2002 .

[11]  Serge Rambal,et al.  Evaluation of the potential of MODIS satellite data to predict vegetation phenology in different biomes: An investigation using ground-based NDVI measurements , 2013 .

[12]  C. Bernhofer,et al.  Investigating the relationship between NDVI and LAI in semi-arid grassland in Inner Mongolia using in-situ measurements , 2009 .

[13]  P. Eilers,et al.  Evaluating the effectiveness of smoothing algorithms in the absence of ground reference measurements , 2011 .