High spatial resolution satellite observations for validation of MODIS land products: IKONOS observations acquired under the NASA Scientific Data Purchase

Phase II of the Scientific Data Purchase (SDP) has provided NASA investigators access to data from four different satellite and airborne data sources. The Moderate Resolution Imaging Spectrometer (MODIS) land discipline team (MODLAND) sought to utilize these data in support of land product validation activities with a focus on the EOS Land Validation Core Sites. These sites provide a globally distributed network of sites where field, aircraft, and satellite data are being collected. As much as possible, uniform data sets useful for validation are being made available for the core sites. The globally consistent, high-resolution imagery available from IKONOS are being used for their geolocation accuracy and ability to characterize the landscape at the 1- to 4-m spatial resolution. This paper provides an overview of the MODIS Land Teamʹs validation strategy to incorporate high-resolution imagery and presents three case studies as examples of the use of IKONOS data for MODIS land validation activities. We conclude that the globally consistent data from IKONOS, available through NASAʹs SDP, have supplied critical validation data sets at a reasonable cost.