A Fast Reprojection Method for MODIS Products with Sinusoidal Projection

Abstract

For studies and applications based on Moderate Resolution Imaging Spectroradiometer (MODIS) products with sinusoidal (SIN) projection, reprojection often is required. But this process can be time-consuming. To accelerate this procedure, this study proposes a practical fast reprojection method that includes 3 major features. (1) Only pixels in target projection space that have corresponding points in MODIS products (“effective pixels”) are further processed. (2) Tags of effective pixels and their corresponding points in MODIS products are retrieved and stored by 1-dimensional (1-D) index of image matrix rather than 2-dimensional subscripts. (3) Pixel values in target images are assigned from MODIS products in bulk rather than in a loop procedure that assigns pixels one by one. In a comparative analysis, the proposed method performs better than the other three tested methods. Based on these improvements, use of prestored 1-D indices of corresponding pixel pairs significantly speeds reprojection. It therefore shows the potential for batch processing of large volume of MODIS products with a SIN projection in reasonable time.