The muse_exp_align recipe =============================================================== .. data:: muse_exp_align Synopsis -------- Create a coordinate offset table to be used to align exposures during exposure combination. Description ----------- Compute the coordinate offset for each input field-of-view image with respect to a reference. The created list of coordinate offsets can then be used in muse_exp_combine as the field coordinate offsets to properly align the exposures during their combination. The source positions used to compute the field offsets are obtained by detecting point sources in each of the input images, unless the source detection is overridden and an input source list is available for each input field-of-view image. In this latter case the input source positions are used to calculate the field offsets. Constructor ----------- .. method:: cpl.Recipe("muse_exp_align") :noindex: Create an object for the recipe muse_exp_align. :: import cpl muse_exp_align = cpl.Recipe("muse_exp_align") Parameters ---------- .. py:attribute:: muse_exp_align.param.rsearch Search radius (in arcsec) for each iteration of the offset computation. (str; default: '30.,4.,2.,0.8') [default="30.,4.,2.,0.8"]. .. py:attribute:: muse_exp_align.param.nbins Number of bins to use for 2D histogram on the first iteration of the offset computation. (int; default: 60) [default=60]. .. py:attribute:: muse_exp_align.param.weight Use weighting. (bool; default: True) [default=True]. .. py:attribute:: muse_exp_align.param.fwhm FWHM in pixels of the convolution filter. (float; default: 5.0) [default=5.0]. .. py:attribute:: muse_exp_align.param.threshold Initial intensity threshold for detecting point sources. If the value is negative or zero the threshold is taken as sigma above median background MAD. If it is larger than zero the threshold is taken as absolute background level. (float; default: 15.0) [default=15.0]. .. py:attribute:: muse_exp_align.param.bkgignore Fraction of the image to be ignored. (float; default: 0.05) [default=0.05]. .. py:attribute:: muse_exp_align.param.bkgfraction Fraction of the image (without the ignored part) to be considered as background. (float; default: 0.1) [default=0.1]. .. py:attribute:: muse_exp_align.param.step Increment/decrement of the threshold value in subsequent iterations. (float; default: 0.5) [default=0.5]. .. py:attribute:: muse_exp_align.param.iterations Maximum number of iterations used for detecting sources. (int; default: 100000) [default=100000]. .. py:attribute:: muse_exp_align.param.srcmin Minimum number of sources which must be found. (int; default: 5) [default=5]. .. py:attribute:: muse_exp_align.param.srcmax Maximum number of sources which may be found. (int; default: 80) [default=80]. .. py:attribute:: muse_exp_align.param.roundmin Lower limit of the allowed point-source roundness. (float; default: -1.0) [default=-1.0]. .. py:attribute:: muse_exp_align.param.roundmax Upper limit of the allowed point-source roundness. (float; default: 1.0) [default=1.0]. .. py:attribute:: muse_exp_align.param.sharpmin Lower limit of the allowed point-source sharpness. (float; default: 0.2) [default=0.2]. .. py:attribute:: muse_exp_align.param.sharpmax Upper limit of the allowed point-source sharpness. (float; default: 1.0) [default=1.0]. .. py:attribute:: muse_exp_align.param.expmap Enables the creation of a simple exposure map for the combined field- of-view. (bool; default: False) [default=False]. .. py:attribute:: muse_exp_align.param.bpixdistance Minimum allowed distance of a source to the closest bad pixel in pixel. Detected sources which are closer to a bad pixel are not taken into account when computing the field offsets. This option has no effect if the source positions are taken from input catalogs. (float; default: 5.0) [default=5.0]. .. py:attribute:: muse_exp_align.param.override_detection Overrides the source detection step. If this is enabled and source catalogs are present in the input data set, the source positions used to calculate the field offsets are read from the input catalogs. If no catalogs are available as input data the source positions are detected on the input images. (bool; default: False) [default=False]. The following code snippet shows the default settings for the available parameters. :: import cpl muse_exp_align = cpl.Recipe("muse_exp_align") muse_exp_align.param.rsearch = "30.,4.,2.,0.8" muse_exp_align.param.nbins = 60 muse_exp_align.param.weight = True muse_exp_align.param.fwhm = 5.0 muse_exp_align.param.threshold = 15.0 muse_exp_align.param.bkgignore = 0.05 muse_exp_align.param.bkgfraction = 0.1 muse_exp_align.param.step = 0.5 muse_exp_align.param.iterations = 100000 muse_exp_align.param.srcmin = 5 muse_exp_align.param.srcmax = 80 muse_exp_align.param.roundmin = -1.0 muse_exp_align.param.roundmax = 1.0 muse_exp_align.param.sharpmin = 0.2 muse_exp_align.param.sharpmax = 1.0 muse_exp_align.param.expmap = False muse_exp_align.param.bpixdistance = 5.0 muse_exp_align.param.override_detection = False You may also set or overwrite some or all parameters by the recipe parameter `param`, as shown in the following example: :: import cpl muse_exp_align = cpl.Recipe("muse_exp_align") [...] res = muse_exp_align( ..., param = {"rsearch":"30.,4.,2.,0.8", "nbins":60}) .. seealso:: `cpl.Recipe `_ for more information about the recipe object. Bug reports ----------- Please report any problems to `Ralf Palsa `_. Alternatively, you may send a report to the `ESO User Support Department `_. Copyright --------- This file is part of the MUSE Instrument Pipeline Copyright (C) 2005, 2019 European Southern Observatory This program is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation; either version 2 of the License, or (at your option) any later version. This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details. You should have received a copy of the GNU General Public License along with this program; if not, write to the Free Software Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02111-1307 USA .. codeauthor:: Ralf Palsa