Error and correction for MODIS-AM's Spatial Response on the NDVI and EVI science products.

摘要

The accuracy of the Moderate Resolution Imaging Spectroradiometer (MODIS) end data products, such as the Vegetation Indices (VIs), are affected by MODIS's Spatial Response (SR). An error analysis is presented for the VI (MOD-13) product using Point Spread Response (PSR) data and improvement using a correction filter is demonstrated. The PSR data is a set of laboratory measurements that include electronic/optical cross-talk (pre-August 1998). The ensquared energy concept is applied to the PSR data to determine upper limits for the Far Field Response (FFR) (unwanted noise) that may be present in the MODIS data. The error analysis is presented using spectral variation, Normalized Difference Vegetation Index (NDVI) and Enhanced Vegetation Index (EVI) which demonstrate that the science products are dependent on the sensor's SR. A correction filter for the MODIS SR shows a qualitative and quantitative improvement using a scene Railroad Valley scene, June 14th 2001 in which Landsat 7 ETM+ is used as the reference.