.. _calobs-nisp-spec-absolute-standards: **CALPRODUCT-NS-002:** NISP-S Absolute Photometric Standards ============================================================ .. include:: definitions.rst Parent requirement ------------------ | `R-CAL-B-NS-3300 `_ | `R-CAL-B-NS-3400 `_ Scheduling ---------- Once, during PV phase. Time-critical ------------- no Objective --------- Obtain absolute flux standard measurements as a function of position for each NISP detector. The absolute zeropoint is determined during PV phase, and subsequent monitoring of relative fluxes in the Self-cal field provide the total throughput at any point of time. If photometric standard stars are available in the Self-cal field, then the absolute throughput could be monitored with the Self-cal data alone. Currently, candidate spectro-photometric standards are available, but the HST observations required for confirmation and determining their true SEDs have not yet been obtained. Fulfilled by ------------ :ref:`calobs-block-pv-nisp-spec-absolute-standards` :ref:`calobs-block-f-wide-survey` Targets and pointing constraints -------------------------------- :command:`Pointing`: Must check that the 1st and 0th order of the standard does not overlap with those of other sources. This can tightly constrain the times at which a particular grism can be calibrated. .. csv-table:: **Bright spectrophotometric standards**. :download:`CSV file ` :widths: 40, 25, 25, 10, 15, 15, 30 :file: tables/targets-nisp-spec-absolute-standards.dat Data volume ----------- 672960 MB (480 executions of the ROS_D1) Processing input ---------------- :command:`Ground Processing Input Data`: All calibration products to run the standard science pipeline (BPM, darks, flat, nonlinearity etc), reference measurement of standard star, RSR curves (relative spectral response of the system (mirrors, optics, instrument) :command:`Data Description`: Processing output ----------------- spectrophotometric response curve, plots of flux measurements as a function of position, first/second exposure, detector etc. Required accuracy, constraints ------------------------------ spectrophotometric flux measurement / response curve derived from each position shows no >x sigma deviation from mean, flux measurements of first compared to second exposure don't show trend, response curve is reasonably close to what is expected Processing tools ---------------- L1 science pipeline and absolute calibration pipeline, additional offline trend analysis of flux measurements Quality control parameters -------------------------- DataModel: ``_ Contact person -------------- NISP-S calibration scientist .. raw:: latex \clearpage