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_orderpos
• input raw frames: ORDERDEF_<arm> (arm = UVB/VIS), ORDERDEF_<arm>_ON/OFF (arm = NIR)

Description: For each order, the x- and y-position are predicted from the guess tables created by xsh_predict. Around each position, a 1D window in the cross-dispersion direction is filtered by a running median and the x-position of the maximum is determined by a Gaussian fit. These positions are then fit by polynomials, whose coefficients are stored in a table, which is used by xsh_mflat.