A freeware-based multispectral data analysis tool kit for satellite data has been developed to assist research and development of remote sensing applications as well as education and training of remote sensing scientists; it is called HYDRA-HYperspectral data viewer for Development of Research Applications. HYDRA provides a fast and flexible interface that allows users to explore and visualize relationships between radiances (or reflectances and brightness temperatures and wavelength (or wavenumber) using spectra diagrams, cross sections, scatter plots, mulichannel combinations, and color enhancements on a a pixel-by-pixel basis with full access to the underlying metadata of location and time.