f2info -- Generic information on FLAMINGOS-2 data and reduction
The F2 package contains tasks for processing FLAMINGOS-2 imaging, longslit and multi-object spectroscopy (MOS) data. Many routines for the proper reduction of infrared imaging and spectroscopic data already exist within the Gemini IRAF package. Therefore, imaging, longslit and MOS reduction will also make use of the tasks in the NIRI and GNIRS packages, respectively. The specifics of the individual tasks can be found in their help files.
This document describes the general use tasks specific to the F2 package and gives a description of the FLAMINGOS-2 data format. For information on the NIRI and GNIRS packages, see niriinfo and gnirsinfo, respectively. More details on data processing for each configuration are available in f2infoimaging (imaging), f2infols (longslit) and f2infomos (MOS). In addition, the f2examples task provides sample processing scripts for all configurations.
The F2PREPARE task is used to prepare the FLAMINGOS-2 raw data from Gemini South. The output imaging, longslit and MOS data from F2PREPARE are similar to the native format for NIRI imaging, GNIRS longslit and GNIRS cross-dispersed data, respectively. This allows for subsequent processing with the NIRI and GNIRS packages.
The tasks are designed to provide a fairly complete and flexible reduction for the purpose of assessing data quality at the time of observation. Real-time reductions may not be optimal for a particular science application. The F2, NIRI and GNIRS package scripts can be optimised for a particular application using the hidden parameters to achieve the best possible results.
The tasks produce logfiles for the performed processing steps. The name of the logfile may be set in each individual task or at the package level by setting f2.logfile.
The tasks add header keywords to the output images. These header keywords contain information about the performed processing steps and the values of the critical parameters that were used.
All FLAMINGOS-2 images are written as multi-extension FITS (MEF) files. Raw data have two unnamed extensions. Most of the header information is written to the primary header unit (PHU), which is extension . The data read from the array is in the pixel data extension, which is extension .
It is recommended to use imtype="fits". This is set automatically when loading the GEMINI package.
The task NSHEADERS sets the header parameters used by the various tasks in the F2, NIRI and GNIRS packages (some header values that have values fixed by IRAF or FITS conventions are not included, since they cannot be changed). After being processed with F2PREPARE, FLAMINGOS-2 data extensions will be named as defined by NSHEADERS.
Before beginning to reduce FLAMINGOS-2 data, NSHEADERS should always be run:
ecl> nsheaders f2
Note that not all header parameters named in NSHEADERS need appear in the raw data. Some are used internally by the F2, NIRI and GNIRS packages. Others are used by F2PREPARE alone.
- F2PREPARE - Prepare raw FLAMINGOS-2 data for reduction
All raw FLAMINGOS-2 data must be processed with F2PREPARE before further processing. F2PREPARE adds certain essential header keywords to the PHU. By default (see NSHEADERS), the extension names are SCI for science data, VAR for variance and DQ for data quality (0 = good). The variance and data quality extensions can be computed by setting the fl_vardq parameter to yes. F2PREPARE can also apply a linearity correction by setting the fl_correct parameter to yes (not yet implemented). Saturated and/or non-linear pixels can be flagged by setting the fl_saturated and/or fl_nonlinear parameters to yes. In addition, bad pixels will be flagged if an input bad pixel mask (BPM) is given for the value of the bpm parameter. Information about the array characteristics are contained in a FITS look-up table called f2array.fits. Finally, F2PREPARE will add an MDF file, describing which areas of the image contain useful information, to MOS data.
The tasks in the F2, NIRI and GNIRS packages are designed to operate on MEF images that have been processed using F2PREPARE. The task F2PREPARE will not run on data from instruments other than FLAMINGOS-2 and will not run on simple FITS files.
f2prepare, f2examples, f2infoimaging, f2infols, f2infomos, gnirs.nsheaders, niri.niriinfo, gnirs.gnirsinfo