Estimation of crop gross primary production (GPP): I. impact of MODIS observation footprint and impact of vegetation BRDF characteristics

•We report MODIS observation footprint impact and BRDF impact on crop daily GPP estimates.•Both impacts varied with crop types, irrigation options, and vegetation index options.•Crop daily GPP estimation reduced uncertainty by combining only observations with view angle ≤35°.•The model with offset had better performance than the model without offset.•EVI and CIgreen had different probabilities to perform best among the four VIs.