.. index:: Self calibration .. _calobs-block-f-selfcal: **CALBLOCK-F-001:** Self Calibration ==================================== .. include:: definitions.rst Observation configuration file ------------------------------ | :download:`ocf_CALBLOCK-F-001_VISIT-1.csv ` | :download:`ocf_CALBLOCK-F-001_VISIT-2.csv ` | :download:`ocf_CALBLOCK-F-001_VISIT-3.csv ` | :download:`ocf_CALBLOCK-F-001_VISIT-4.csv ` Scheduling ---------- Scheduled every 25-40 days, adding flexibility for survey planning. In case of failure, skip and continue with survey plan. Dependencies ------------ None Objective --------- These observations provide the baseline to monitor Euclid's spectrophotometric response to space weathering and outgassing. This is achieved by multiple dithered exposures of the Self-cal field. Observations ------------ * Execute the ROS_D1 with a specific grism, at each of 60 pointings * A total of 4 self-cal visits is required to observe all grisms at all 60 dithers * BGS observations require an :math:`{\rm AA}` offset of at least :math:`\pm1.4` to facilitate spectra-order decontamination, better :math:`\pm2.0`. Whether the negative or positive offset is executed first does not matter. Should the blue-grism offsets violate MOCD-A requirements, then they may be chosen asymmetrically around :math:`{\rm AA}`. However, this could imply a large slew that impacts the thermal equilibrium. In that case EC-SURV may consider scheduling the Self-cal visit at another time. * The grism order must be preserved as outlined in the pseudo-code, as it can be executed any time without violating slew constraints. * :math:`{\rm AA}` may vary during a visit due to orbit progression * :math:`{\rm AA}` can be fine-tuned around :math:`{\rm AA}=-5.5` to minimise thermal transients and meet VIS straylight requirements, but the offset blue-grism observations must stray within the allowed limits. * The illumination-correction maps for the VIS and NISP imaging channels can exploit the additional, rotated blue-grism dithers, bringing the total from 60 to 76 exposures. * Note the rolling order of the red grisms in the 4 visits * The blue grism repeats 4 central dithers at the end of the 4th configuration * The ROS_D1 VIS variants are mostly NominalScience+ShortScience [NS+SS] (72 pointings), with 4 cases of [NS+Bias] distributed evenly. The 4 biases provide instrumental reference; each Self-cal visit starts and ends with the NS+BI variant of the ROS_D1. The Short Science exposures are required for VIS absolute photometric calibration, as well as BFE and NL monitoring. .. code-block:: python :caption: **Self-cal visit 1. BGS offset must be at least 1.4, ideally 2:** ma ~ -5.5 (chosen AA for red-grism observations) Set AA = ma-2 Dithers 42, 44, 45, 48, 2, 3, 30, 32: BGS000 Set AA = ma Execute 60 dithers as specified, red-grism order: RGS000, RGS180_rot, RGS000_rot, RGS180, repeat Set AA = ma+2 Dithers 41, 43, 47, 46, 1, 4, 29, 31: BGS000 .. code-block:: python :caption: **Self-cal visit 2:** Set AA = ma-2 Dithers 53, 54, 49, 50, 37, 39, 26, 25: BGS000 Set AA = ma Execute 60 dithers as specified, red-grism order: RGS180_rot, RGS000_rot, RGS180, RGS000, repeat Set AA = ma+2 Dithers 56, 55, 51, 52, 38, 40, 28, 27: BGS000 .. code-block:: python :caption: **Self-cal visit 3:** Set AA = ma-2 Dithers 10, 11, 5, 7, 23, 21, 18, 19: BGS000 Set AA = ma Execute 60 dithers as specified, red-grism order: RGS000_rot, RGS180, RGS000, RGS180_rot, repeat Set AA = ma+2 Dithers 9, 12, 6, 8, 22, 24, 17, 20: BGS000 .. code-block:: python :caption: **Self-cal visit 4:** Set AA = ma-2 Dithers 13, 14, 33, 36, 57, 58, 41, 42: BGS000 Set AA = ma Execute 60 dithers as specified, red-grism order: RGS180, RGS000, RGS180_rot, RGS000_rot, repeat Set AA = ma+2 Dithers 16, 15, 34, 35, 59, 60, 43, 44: BGS000 Fulfilling ---------- | :ref:`calobs-nisp-bfe` | :ref:`calobs-nisp-phot-absolute-standards` | :ref:`calobs-nisp-phot-distortion` | :ref:`calobs-nisp-phot-large-scale-flats` | :ref:`calobs-nisp-phot-psfmodel` | :ref:`calobs-nisp-phot-dichroic-ghostmodel` | :ref:`calobs-nisp-spec-dichroic-ghostmodel` | :ref:`calobs-nisp-spec-0thordercentroid` | :ref:`calobs-nisp-spec-absolute-standards` | :ref:`calobs-nisp-spec-distortion` | :ref:`calobs-nisp-spec-large-scale-flats` | :ref:`calobs-nisp-spec-trace` | :ref:`calobs-nisp-spec-wavelength-dispersion-check` | :ref:`calobs-vis-absolute-standards` | :ref:`calobs-vis-bfe` | :ref:`calobs-vis-crosstalk` | :ref:`calobs-vis-distortion` | :ref:`calobs-vis-large-scale-flats` | :ref:`calobs-vis-ghostmodel` | :ref:`calobs-vis-shuttermap` Targets and pointing constraints -------------------------------- :command:`Pointing`: Straylight suppression as per MOCDA-SYS-003. The 60 dithers for the red grism should be observed at the mean :math:`{\rm AA}` of the contemporary survey patch. They must be executed in the order given in :download:`CSV file `. The 16 dithers for the blue grism use two different :math:`{\rm AA}` offset with respect to the mean :math:`{\rm AA}` of the survey patch. .. figure:: ../images/selfcal_location_zoom.png :scale: 33% The Self-cal field is located near the NEP. It includes a hot White Dwarf (blue asterisk) for :ref:`calobs-block-pv-absolute-standards-imaging`. The green and orange outlines show the boundaries for visits at two different times, where orbit progression results in boundary rotation. .. figure:: ../images/selfcal-dithers.png :scale: 100% Self-cal dither pattern. Observations must step through the dithers as specified in this :download:`CSV file ` .. csv-table:: **Self-cal field** :download:`CSV file ` :file: tables/targets-selfcal-center.dat Instrument configuration ------------------------ Instrument: Wide survey Methodology / Uplink procedure ------------------------------ :command:`Entity`: VIS & NISP :command:`Commanding Method`: NISP: Observation, VIS: Science :command:`Dither Sequence`: ROS_D1. The ROS_D1 is executed at each of these :download:`Self-cal dither positions `. The order in which they are executed does not matter, within a fixed :math:`{\rm AA}` setting. The grism to be used at a specific dither is given in the observations. Inter-operability constraints ----------------------------- None In-orbit duration ----------------- :command:`In-orbit Duration`: 23.5 h Data volume ----------- ``76*ROSD1 = 99028 MB`` Processing input ---------------- :command:`Ground Processing Input Data`: All calibration products to run the standard science pipeline (BPM, darks, flat, nonlinearity etc), small scale flat fields :command:`Data Description`: Each visit provides: 225 photo-MACC images, 76 spectro-MACC images, 76 VIS nominal science, 72 VIS short science exposures, and 4 VIS bias exposures. Processing output ----------------- * Large scale flat field for VIS and all NISP filters and grisms * NISP-S dispersion check using secondary wavelength calibrators * Absolute photometric zeropoint for VIS and NISP. * Coarsely binned (e.g. 100x100) illumination correction map, and monitoring * VIS and NISP focal plane astrometric solutions * Monitoring of system parameters. Required accuracy, constraints ------------------------------ Images successfully acquired Processing tools ---------------- Pipeline: VIS_LargeFlatCalibration_Pipeline PE: VIS_LargeFlatCalibration Quality control parameters -------------------------- DataModel: ``_ Contact person -------------- Calibration Lead .. raw:: latex \clearpage