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Order Merging

Finally, the extracted orders, sampled at constant wavelength steps and corrected for the blaze effect, can be merged into a one dimensional spectrum which is suitable for further analysis. The merging  algorithm computes a weighted average in the overlapping region of adjacent orders. The normalised weight is a linear ramp changing from 0 to 1 in the overlapping region for each of the adjacent orders. Therefore, in the overlapping region of two consecutive orders, the ramp decreases linearly for the `blue' order while it increases linearly for the `red' order. This gives less weight to points near the edges of the orders. It is also possible to extract individual orders and store them in different spectral files for further analysis. The command MERGE/ECHELLE performs the merging of the orders.

Petra Nass