.. _NIRStackedFrame: NIR Stacked Frame ================= $SetSchemaPath nir/euc-test-nir-StackedFrame.xsd Data product name _________________ .. DataProductNameStart $PrintDataProductName .. DataProductNameEnd Data product custodian ______________________ .. DataProductCustodianStart $PrintDataProductCustodian .. DataProductCustodianEnd Name of the Schema File ________________________ .. NameSchemaStart $PrintSchemaFilename .. NameSchemaEnd Last Edited for DPDD Version ____________________________ .. DpddVersionlTagStart 1.1 .. DpddVersionTagEnd Processing Elements Creating / Updating / Using the Product ___________________________________________________________ .. PECreatorStart **Creators:** * NIR The **DpdNirStackedFrame** data product components are created by different tasks during the execution of the *NIR_ProcessField_Pipeline*: * The :term:`MEF` file is created by the **NIR_DostackProgram** task of the *NIR_Stacking* project * The PSF model and image are created by the **NIR_PSFModelling** task of the *NIR_PointSpreadFunction* project * The data product xml is written by the final *NIR_ProcessField_Pipeline* step that is **NIR_CreateScientificDpds** of *NIR_Utilities* project **Consumers:** * NIR Into the *NIR_ProcessField_Pipeline* the :term:`MEF` file is used as input for the **NIR_CatalogExtraction** PE to create the :ref:`NIRStackedFrameCatalog` containing source extracted. .. PECreatorEnd Processing Function using the products ______________________________________ .. PFUsingStart .. Indicate here the PF you are aware of using the product. Can be the custodian PF itself for internal product. Can also be Science Working Group for final products. The list does not need to be exhaustive. This is one of the output of the *NIR_ProcessField_Pipeline*. In the pipeline the :term:`MEF` file is used as input for the **NIR_CatalogExtraction** PE to create the :ref:`NIRStackedFrameCatalog` with source extracted. * PF-NIR .. PFUsingEnd Proposed for inclusion in EAS/SAS _________________________________ .. IncludeInSASStart This product is proposed for inclusion in the SAS: **yes** .. IncludeInSASEnd Data Product Elements _____________________ .. DataProductElementsStart $PrintDataProductElements .. DataProductElementsEnd Detailed Description of the Data Product _________________________________________ .. DetailedDescStart The **DpdNirStackedFrame** is one of the output of the *NIR_ProcessField_Pipeline* applied to wide survey observations and in general to "scientific" pointings (i.e. Self Calibration). It is the result of the stacking process of a set of input images, 4 in case of wide, the nominal survey strategy. It could be created also in some specific cases with more exposures. A single stacked image is provided at the end of each *NIR_ProcessField_Pipeline* run. .. _NIR_stacked_frame_catalog: .. figure:: ../figures/nirStackedFrame.png :scale: 100 % :align: center :figclass: align-center : Graphical representaton of ``Data`` section structure for **DpdNirStackedFrame** The main elements inside the *Data* section are: * **Filter**: The filter name (e.g. NIR_Y, NIR_J, NIR_H) * **WCS**: The description of the WCS for the image. This field mirrors values in the FITS header * **ZeroPoint**: The effective photometric zero point of this stack of single images * **ImgSpatialFootprint**: This spatial area defines the spatial footprint of the image in a series of vertex * **ObservationId**: Image Observation Id * **TargetPointing**: Coordinates of target pointing * **DataStorage**: FITS file name containing the Stacked image FITS file * **PsfStorage**: Reference to the PSF files (Model and FITS) * **QualityParams** (optional):Data Quality Parameters * **Min**: Minimum image pixel value * **Max**: Maximum image pixel value * **Mean**: Average image level (mean of all image pixel values) * **Median**: Median image level (median of all image pixel values) * **StDev**: Sample standard deviation of the image pixel values * **MaskedPixelFraction**: The fraction of masked pixels The **DpdNirStackedFrame** data product contains the link to 3 files: * a :term:`MEF` file with the science image * a PSF model measured from science frames * a PSF image of the model Scientific image FITS file ^^^^^^^^^^^^^^^^^^^^^^^^^^ The main result of the stacking process is a :term:`MEF` file stored into the **DpdNirStackedFrame** in the ``Data.DataStorage`` field. The file is composed by four layers: ============ ================= =============== ======================== Layer name Data Format Units Content ============ ================= =============== ======================== **PRIMARY** Main headers **SCI** *float32* microJy Scientific data **RMS** *float32* microJy RMS data **DQ** *int32* Data Quality mask ============ ================= =============== ======================== .. _NIR_stacked_frame_image: .. figure:: ../figures/stacked_frame.png :scale: 100 % :align: center :figclass: align-center : Graphical representation of 3-layer structure of NIR stacked frames Primary layer """""""""""""" The primary layer is an header dedicated to store global infomation on pointings and parameters used by SWarp for resampling and stacking (i.e. starting from *COMBINET*, *RESAMPT1* up to *PSCALET2* in the next table) together with the inverse sensitivity value *PHOTFNU* needed to convert pixels in [microJy]. $PrintPrimaryHeader fit/euc-nir.xml nir.stackedImage Scientific Layer """""""""""""""" The scientific layer, named **SCI**, stores the data obtained combining togheter all images used as input to the NIR Pipeline. The header contains some basic image definition keywords together with the *GAIN* and the *SATURATE* keywords derived by SWarp for resampling and stacking. $PrintExtensionHeader fit/euc-nir.xml nir.calibratedScienceFrame DETn.SCI RMS Layer """"""""" The RMS layer is DQ Layer """""""" The DQ layer is PSF files description ^^^^^^^^^^^^^^^^^^^^^ The Point Spread Function (PSF) is measured from the image. It is provided into two formats: a `.psf` file containing model parameters and a `.fits` file with an instance of model. A PSF model is extracted from the scientific image by PSFEx software. This solution is provided both as **model** and as **image**. The PSF **model** is produced as *.psf* file, an Astromatic format that can be directly provided to SExtractor for catalogue extraction. The model can track wavelength and focal plane position dependencies. The PSF **image** is a FITS file with a primary and a single data layer containing a PSF image. PSF Model file """""""""""""" This is a model file PSF image file """""""""""""" The PSF primary header contains information on Observation Id in *OBS_ID*. Because of the FITS structure is in common with the one used on :ref:`NIRCalibratedFrame` definition some keywords are meaning-less in case of stacked frame. As in example *DITHOBS* could be ignored and *PSFTYPE* is fixed to *"Inflight"* value because the PSF is always extracted from images. $PrintPrimaryHeader fit/euc-test-nir.xml nir.psfImage The detector header collects basic image keywords with the coordinates of PSF image center in pixel space (*X_CENTR* and *Y_CENTR*) and the effective wavelength (*EFF_WAVE*). $PrintExtensionHeader fit/euc-test-nir.xml nir.psfImage DETECTOR.n .. DetailedDescEnd