fv Overview

This document provides an introduction to the main features of the fv viewer and editor of FITS format images and tables. FITS is the standard format that is universally used by researchers and observatories for astronomical data files. It is important to realize that FITS is much more than just another image format, such as GIF or JPG, and that FITS files can store many different images and tables all merged into a single file. The main purpose of fv then is to provide an easy-to-use tool for examining and editing the contents of any FITS file.

While we often refer to fv as a single program, it is actually composed of 2 fairly independent pieces. The first part is fv itself which reads and writes FITS files, provides editing capabilities for header keywords, and has spreadsheet type functions for examining the pixels in an image or the entries in a table. The second part is the POW graphics tool that is used by fv to display images and to plot graphs. POW is an independent tool, but it has been closely integrated with fv.

In this brief tutorial it is only possible to describe some of the main features of the fv program. After completing the tutorial you can then go back and study the help files that are available from each fv window to learn more about other capabilities.