Ground based measurements for interpretation of vegetation indices over developing countries

Satellite derived vegetation indices (VIs) are valuable tool to evaluate the role of vegetation in the exchange of radiation, momentum and heat during atmosphere-biosphere interactions. Besides accurate description of land, vegetation dynamics and ecological conditions, VIs can be used for estimating primary productivity, drought monitoring, crop yield prediction, detecting weather impacts and other events relevant to ecology and agricultural productivity. However, the true potential of VIs can only be realised if it is supported and validated through concurrent field experiments. The scaling problems between wide ranging atmospheric processes to small space, space-time biophysical phenomena can also be resolved through satellite derived VIs backed-up by ground truth experiments. Sensor calibration, atmospheric-geometric correction, radiance to parameters calculation, etc., are some crucial technical issues which could be addressed through ground experiments. Complex, multidisciplinary and resource intensive nature of ground experiments in support of satellite derived VIs interpretation call for meaningful international cooperation. This is inevitable in view of evolving scientific solutions to global environmental problems.