Downloading and reformatting tool for NASA Earth observation data products(GSC-18095-1)

This R software package (nasaaccess), is expandable.The 'nasaaccess' software package current version processes remote sensing data products (i.e., TRIMM, IMERG, and GLDAS) and creates weather input definition tables as well as stations data files in a format readable by earth science model. The package can be expanded to include other remote sensing products needed in future. For the time being (nasaaccess version 1.2) generates daily rainfall and minimum and maximum air temperatures gridded data and gridded data definition files needed to serve as a setup for any basic earth science hydrological model run. The climate time seriesoutputs are either at a pseudo grid located at the centeroid of the watershed provided or at grids within the specified watershed provided. The core functionality of the package is accessing GSFC servers to: download climate data, clip needed grids based on a user study watershed shapefile and DEM grid, handle temporal issues and then to generate daily climate gridded data files and definition files compatible with various hydrological models. The functions within the package ask the user for inputs which are: start and end dates for his climate data simulation, a shapefile for his studywatershed, and a DEM for his study watershed. The functions then output the gridded data ascii files and the definition files right at his desired working folder. The package has examples and detail explanation of the process being done (metadata is included).