A custom EASE-Grid SSM/I processing system

A task fundamental to advancing global change research is the availability of a standard reference system for direct digital comparison and interuse of remote sensing data sets on varying spatial and temporal scales. The availability of a standard gridding scheme is an essential requirement for systematic time-series studies. Such a scheme also supports the direct comparison of different remote sensing products, as well as the validation of algorithms, through digital comparison with surface station and other ancillary data sets which have been processed into the common grid. New software now allows users of Special Sensor Microwave/Imager (SSM/I) data to produce their own Equal-Area Scalable Earth Grid (EASE-Grid) image data from Temperature Data Record (TDR) format swath data. Overlapping orbit data are separately retained for the highest possible temporal resolution, and data for specific pixels can be extracted. The modular processor also simplifies testing of alternative resampling and gridding algorithms. The EASE-Grid is a standard gridding scheme now used with a variety of satellite datasets, including SSM/I data, its original application. Although the specific method used to interpolate from native sensor coordinates to a fixed Earth grid is unique to each sensor, the fundamental projection and gridding concept of the EASE-Grid provides the basis for a standard interuse gridding method. Thus, the SSM/I EASE-Grid is composed of two fundamental parts: i) a grid and projection scheme and, 2) a specific method to interpolate SSM/I data from swath space to Earth gridded coordinates. The projection and gridding scheme is independent of the satellite sensor or data type.