# Local Search for Optimal Global Map Generation Using Mid-Decadal Landsat Images

Robert A. Morris, Lina Khatib, John Gasch, Steven Covington

NASA and the US Geological Survey (USGS) are seeking to generate a map of the entire globe using Landsat 5 Thematic Mapper (TM) and Landsat 7 Enhanced Thematic Mapper Plus (ETM$+$) sensor data from the mid-decadal'' period of 2004 through 2006. The global map is comprised of thousands of scene locations and, for each location, tens of different images of varying quality to chose from. Furthermore, it is desirable for images of adjacent scenes be close together in time of acquisition, to avoid obvious discontinuities due to seasonal changes. These characteristics make it desirable to formulate an automated solution to the problem of generating the complete map. This paper formulates a Global Map Generator problem as a {\em Constraint Optimization Problem} (GMG-COP) and describes an approach to solving it using local search. Preliminary results of running the algorithm on image data sets are summarized. The results suggest a significant improvement in map quality using constraint-based solutions.

Subjects: 15.2 Constraint Satisfaction; 1. Applications

Submitted: May 17, 2007