The visir_util_detect_shift recipe =============================================================== .. data:: visir_util_detect_shift Synopsis -------- 2012 Description ----------- Detects beams in a background subtracted multi-beam image, determines the shifts between different images and their correlation. Images can be rejected if their correlation is bad. The files listed in the Set Of Frames (sof-file) must be tagged: VISIR-chopnod-corrected-file.fits BKG_CORRECTED bad-pixel-mask.fits STATIC_MASK The output consists of single beam images of the size of the throw. The shifts will be written int CRPIX[12]. Constructor ----------- .. method:: cpl.Recipe("visir_util_detect_shift") :noindex: Create an object for the recipe visir_util_detect_shift. :: import cpl visir_util_detect_shift = cpl.Recipe("visir_util_detect_shift") Parameters ---------- .. py:attribute:: visir_util_detect_shift.param.template Correlation template used to detect shifts and reject bad images. If none given an averaged image is used (str; default: 'NONE') [default="NONE"]. .. py:attribute:: visir_util_detect_shift.param.min_correlation Minimal correlation to the template required to be accepted (float; default: 0.5) [default=0.5]. .. py:attribute:: visir_util_detect_shift.param.max_shift Maximal allowed object shift for an image to be accepted (float; default: 10.0) [default=10.0]. .. py:attribute:: visir_util_detect_shift.param.max_mad Maximal allowed median absolute deviation for an image to be accepted. <= 0 equals no limit (float; default: 0.0) [default=0.0]. .. py:attribute:: visir_util_detect_shift.param.naverage Number of planes to average before attempting to detect the shifts. (int; default: 1) [default=1]. .. py:attribute:: visir_util_detect_shift.param.method Method to determine beam shifts. xcorrelate: use the cross correlation shift. brightest: use the position of the brightest pixel (str; default: 'xcorrelate') [default="xcorrelate"]. .. py:attribute:: visir_util_detect_shift.param.no_shift Sets whether to apply the determined shifts in following recipes. Set to TRUE of shifts appear too large. (bool; default: False) [default=False]. .. py:attribute:: visir_util_detect_shift.param.no_reject If true images with bad statistics will not be rejected and no shift correction is done (bool; default: True) [default=True]. .. py:attribute:: visir_util_detect_shift.param.beampos Define the positions of the beams. These positions are cut by the window to extract the single beam images. Format: sign:x,y,window;sign:x,y,window;... where sign is "pos" or "neg" depending on whether the beam is positive or negative. The window is optional and defines the size of the cut image around the beam. The default window is the chop throw. E.g.: pos:50,60;neg:50,160; By default autodetection is attempted. (str; default: 'NONE') [default="NONE"]. .. py:attribute:: visir_util_detect_shift.param.eccmax The maximum eccentricity allowed in the combination of the three (in parallel nod/chopping) or four (in perpendicular nod/chopping) beams. In parallel mode, three perfectly aligned points spaced with the chopnod throw will have eccentricity 0, while in perpedicular mode a square with the chopnod throw as the side length will have eccentricity 0 (float; default: 3.0) [default=3.0]. The following code snippet shows the default settings for the available parameters. :: import cpl visir_util_detect_shift = cpl.Recipe("visir_util_detect_shift") visir_util_detect_shift.param.template = "NONE" visir_util_detect_shift.param.min_correlation = 0.5 visir_util_detect_shift.param.max_shift = 10.0 visir_util_detect_shift.param.max_mad = 0.0 visir_util_detect_shift.param.naverage = 1 visir_util_detect_shift.param.method = "xcorrelate" visir_util_detect_shift.param.no_shift = False visir_util_detect_shift.param.no_reject = True visir_util_detect_shift.param.beampos = "NONE" visir_util_detect_shift.param.eccmax = 3.0 You may also set or overwrite some or all parameters by the recipe parameter `param`, as shown in the following example: :: import cpl visir_util_detect_shift = cpl.Recipe("visir_util_detect_shift") [...] res = visir_util_detect_shift( ..., param = {"template":"NONE", "min_correlation":0.5}) .. seealso:: `cpl.Recipe `_ for more information about the recipe object. Bug reports ----------- Please report any problems to `Find beam positions and reject bad images `_. Alternatively, you may send a report to the `ESO User Support Department `_. Copyright --------- This file is part of the VISIR Instrument Pipeline Copyright (C) https://support.eso.org 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:: Find beam positions and reject bad images