FTOOLS

FTOOLS is a collection of modular command-line software tools designed for the analysis of astronomical data stored in FITS (Flexible Image Transport System) format. Developed and distributed by NASA’s Goddard Space Flight Center, it is part of the HEASoft software package used by researchers in high-energy astrophysics to process and analyze data from various space-based and ground-based instruments.

Historically, FTOOLS originated in the late 1980s as a set of FORTRAN utilities intended to provide instrument-agnostic capabilities for FITS data. Over time it evolved into a framework of compact utilities, each performing a specific task such as extracting data, rebinning, filtering event lists, or updating FITS headers. Users commonly chain multiple tools in scripts to form analysis pipelines tailored to particular instruments or scientific goals.

Technical approach and scope emphasize interoperability with FITS standards. Tools typically operate on single tasks and can read and write standard FITS files and derivatives, including event lists, images, and tables. They interact with FITS headers and metadata, and many utilities rely on the CFITSIO library to handle FITS I/O. The tools are designed to run on multiple platforms and integrate with the broader HEASoft environment.

Current status and usage: FTOOLS remains part of the HEASoft distribution and is maintained for legacy data analysis and instrument-specific workflows. While increasingly complemented by modern Python-based toolchains (such as Astropy-based workflows), FTOOLS continues to be valued for legacy datasets and for certain standardized tasks within high-energy astrophysics research.