Implementation of the Mid-Decadal Global Land Survey
The U.S. Geological Survey (USGS) and the U.S. National Aeronautics and Space Administration (NASA) have joined together to augment a series of decadal global land surveys with an update based around the 2005-2006 time period. The Mid-Decadal Global Land Survey (MDGLS) will follow the datasets from the 1970’s, 1990 and 2000, while increasing the total coverage and, for the first time, include Antarctica.
The MDGLS project has been organized into two phases with the USGS leading the first phase: Data Acquisition, and NASA leading Phase 2: Product Generation. For Phase 1, first consideration is given to the data acquisition specification for seasonality based on geographic location, climate and land cover, and a desire to provide products with a temporal compatibility to previous surveys; facilitating land cover/land use change analysis across the four survey epochs.
Equal consideration is given to the sensor data to be used. The 1990 survey primarily used Thematic Mapper (TM) data while the 2000 survey used Enhanced Thematic Mapper Plus (ETM+) imagery exclusively. The ETM+ data has superior radiometric and geometric fidelity, but now suffers from the failure of its scan line corrector. TM data has lowered, but still adequate data quality when compared to ETM+ imagery, but is unable to collect imagery over many parts of the Earth, and the vast majority of its global collection is contained in the archives of the Landsat Program’s International Cooperators. Alternate data sources such as EO-1’s Advance Land Imager (ALI) and Terra’s ASTER instruments have varying levels of radiometric, geometric and acquisition parameter complexities to be considered.
This presentation will cover the status of the Landsat 5 and Landsat 7 missions and the approach used to address and answer the challenges encountered during Phase 1 of the MDGLS project.