A Simple Fusion Mehtod for Image Time Series Based on the Estimation of Image Temporal Validity

High-spatial-resolution satellites usually have the constraint of a low temporal frequency, which leads to long periods without information in cloudy areas. Furthermore, low-spatial-resolution satellites have higher revisit cycles. Combining information from high- and low- spatial-resolution satellites is thought a key factor for studies that require dense time series of high-resolution images, e.g., crop monitoring. There are several fusion methods in the bibliography, but they are time-consuming and complicated to implement. Moreover, the local evaluation of the fused images is rarely analyzed. In this paper, we present a simple and fast fusion method based on a weighted average of two input images (H and L ), which are weighted by their temporal validity to the image to be fused. The method was applied to two years (2009-2010) of Landsat and MODIS (MODerate Imaging Spectroradiometer) images that were acquired over a cropped area in Brazil. The fusion method was evaluated at global and local scales. The results show that the fused images reproduced reliable crop temporal profiles and correctly delineated th e boundaries between two neighboring fields. The great est advantages of the proposed method are the execution time and ease of use, which allow us to obtain a fused image in less than five minutes

Space and biotechnology: An industry profile

The results of a study conducted by the Center for Space and Advanced Technology (CSAT) for NASA-JSC are presented. The objectives were to determine the interests and attitudes of the U.S. biotechnology industry toward space biotechnology and to prepare a concise review of the current activities of the biotechnology industry. In order to accomplish these objectives, two primary actions were taken. First, a questionnaire was designed, reviewed, and distributed to U.S. biotechnology companies. Second, reviews of the various biotechnology fields were prepared in several aspects of the industry. For each review, leading figures in the field were asked to prepare a brief review pointing out key trends and current industry technical problems. The result is a readable narrative of the biotechnology industry which will provide space scientists and engineers valuable clues as to where the space environment can be explored to advance the U.S. biotechnology industry