Munipack ‒ Introduction

# Introduction

An introduction to philosophy of Munipack framework and a short summary of provided features.

## Overview

Munipack is a general framework intended on processing of astronomical images. The framework implements methods for extracting photometry and astrometry information from the image data. All the implemented methods regards on robust algorithms, fast and effective processing.

Munipack is intended for processing of very large data by professionals, with flexibility of use, a wide compatibility with other astronomical tools (Virtual Observatory) and data formats (data can be accessed and modified with help of external utilities) in mind.

## Command line interface

Munipack can be used via the user interfaces: a graphical and a command-line. This manual is focused on the command-line usage which provides all implemented features. Opposite with this, the graphical interface is designed to be easy to use. Therefore a true mean of many actions should be obscured, missed by design or unimplemented yet.

The command-line interface respects Unix conventions. Munipack can be directly used in shell scripts, core routines can be wrapped for various (scripting) languages and integrated to a large processing systems.

## Actions

The command-line interface is provided by only the simple command:

`$ munipack`

The command wrappers individual actions and provides an user input data pre-processing under Unix environment. The direct access for programmers is also possible.

The most typical invocation is in the form:

    $ munipack action [options] files

User specifies the action, seldom options and files to work on its. The action is natural shortcut of a logical action (for instance, the dark correction). The options modifies a default parameters and provide a way for fine tune of a processing. The last argument files specify files to be processed. Usually, names with wildcards (* or ?) are provided. To read filenames from its standard input, a dash (-) should be passed too.

The interface is designed in fashion of widely used control version systems like Mercurial or latest Git. The design has been adopted because regular users (including author) remembers one (maybe two) command-names to call, but not a huge list of various names of commands.

Actions are naturally grouped on categories:

### Preprocessing

There are actions for averaging of biases, dark-frames and flat-field frames and phcorr tool for batch correction of all frames.

### Processing

The images can be processed by many ways. The most common is fully automatic detection of stars and providing of aperture photometry on images.

Frames with known stars can be astrometricaly and photometrically calibrated. To get more precise calibration by multi-filter observation, the instrumental photometry system must be transformed to a standard equivalent and converted to various photometry quantities like magnitudes (in a filter, STmag and ABmag) or fluxes (in a filter, per wavelength or frequency unit).

### Products

From calibrated images, one can construct a time series (with light curve as a special case) or construct a mosaic or sum images with more deeper exposure.

### Colour Images

A set of images can be collected to a Colour FITS image to provide natural colours.

### Virtual Observatory

Just only cone search is implemented from the wide offer of services by Virtual Observatory. The conversion from VOTable format to many another computer formats can be also useful.

### FITS

Munipack wraps some routines provided by cFITSIO library for conventional use in shell scripts.

## Verbose logging

Sometimes, one can be difficult to understand error messages. The option `--verbose` which prints a lot of garbage can help.

## Golden Rule

Before start to play with Munipack, please remember the golden rule: Never touch any data without a backup!

## See Also

☺ User Guide