Project Funding: 2008 - 2011

NRA: 2006 NASA: EOS   

Funded by NASA

Abstract:
The investigators propose to make significant incremental improvements to the MOD44 product suite by exploiting the new opportunities presented by the Collection 5 reprocessed record for Terra and Aqua. First, we have developed a series of experimental methods for mitigating the effects of BRDF on the MOD44C multi-day 250 m resolution composites which are used to create the Vegetation Continuous Fields (MOD44B) and Vegetative Cover Conversion (MOD44A) product streams. In highly vegetated areas, such as broadleaf closed canopy evergreen forest, the effect of BRDF can cause reflectance in the red band to range between .02 and .08 for the same footprint with different viewing geometry over the course of only a few days. By retaining and utilizing information about viewing geometry in the creation of composites, these effects can be managed and mitigated. The effects are much stronger than those seen with heritage instruments due to the superior MODIS spatial resolution, radiometry, and atmospheric correction. Although the effects were present in products such as the AVHRR Pathfinder, they are much more pronounced with MODIS. We propose to use this information to improve the quality of derived land cover products and to anticipate similar effects with VIIRS. Second, we propose to develop regional (continental) versions of the Vegetation Continuous Fields product suite. Current versions are optimized on a global basis, which provides a good mean solution in terms of vegetation cover and characteristics. However, by segmenting training data on a regional basis, we have demonstrated that we can better monitor subtle changes in land cover and also provide superior baseline products in areas with unique local conditions such as persistent cloud cover or the composition of vegetation communities. Finally, we propose to move forward from the Vegetative Cover Conversion global alarm product to an improved version better suited to definitive areal mapping. We propose to utilize an iterative mapping approach developed for our VCC Change Due to Burning product where a conservative land cover change seed is used with an iterative kernel to grow the change polygon to its ultimate spatial extent. Calibration and validation will focus on verifying the improvements in the aforementioned products. We also seek moderate funds to continue our activities with the MODIS Science Team and produce products from Collection 5 and beyond.

2015 NASA Carbon Cycle & Ecosystems Joint Science Workshop Poster(s)

• Accelerated Deforestation in the Humid Tropics from the 1990s to the 2000s   --   (Do-Hyung Kim, Joseph O. Sexton, John R. Townshend)   [abstract]

2011 NASA Carbon Cycle & Ecosystems Joint Science Workshop Poster(s)

• The Abundance, Distribution and Dynamics of Arctic Lakes in North America   --   (Mark Carroll, Tatiana Loboda, John R. Townshend, Robert Sohlberg, Charlene DiMiceli)   [abstract]

2008 NASA Carbon Cycle & Ecosystems Joint Science Workshop Posters

• A Strategy for Developing Earth Science Data Records of Global Forest Cover Change   --   (John R Townshend, Chengquan Huang, Jeffrey G. Masek, Matthew C. Hansen, Ruth S. DeFries, Samuel N. Goward, Compton J. Tucker)   [abstract]
• The Need for a New Moderate Resolution Water Mask for Earth Science   --   (Mark Carroll, John Townshend, Charlene DiMiceli, Robert Sohlberg, Praveen Noojipady)   [abstract]

More details may be found in the following project profile(s):

• NASA Terrestrial Ecology (TE) Project Profile