Disclaimer: The information given here refers to the use of this recipe during QC processing. For more details see the pipeline manual at the pipelines page.

• recipe name:xsh_mflat
• input raw frames: FLAT_<type>_<arm> (type = SLIT/IFU, arm = UVB/VIS), FLAT_<type>_<arm>_ON/OFF (type = SLIT/IFU, arm = NIR)

Description: The input order table from xsh_orderpos is used to locate the centroids of the order, and each order is divided in chunks. In each chunk, the pixels are collapsed to obtain a 1D profile in the cross dispersion direction with enhanced signal-to-noise ratio. If the signal-to-noise ratio at the central pixel is below the threshold the profile is rejected from the order table computation. In the 1D profile the slit edge is defined once the flux gets below a fraction of the central flux. For IFU data the recipe determines the edges of the three slices according to the user-selected method. The set of derived x coordinates for the edges together with the corresponding central y coordinates of the chunks is used to compute the edge order table. The interorder background is fit with a spline using the median flux of small windows between the orders.