Flexible Image Transport System Date Format（FITS）TOOLS
Documents
User Guide( https://archive.stsci.edu/fits/users_guide/ )
FITS Data Dictionary( https://heasarc.gsfc.nasa.gov/docs/fcg/standard_dict.html )
FITS World Coordinate System( https://fits.gsfc.nasa.gov/fits_wcs.html )
Software and Tools
FITS I/O Libraries（ https://fits.gsfc.nasa.gov/fits_libraries.html ）
FITS Image Software Packages for image viewing, analysis, and format conversion（ https://fits.gsfc.nasa.gov/fits_viewer.html ）
FITS Utility Software（ https://fits.gsfc.nasa.gov/fits_utility.html ）