According to

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<ul>
<li><tt> VLT-SPE-SPH-14690-0083 (SPHERE Technical Specification)</tt>
<li><tt> VLT-SPE-SPH-14693-0082 (SPHERE Technical Specification)</tt>
<li><tt> VLT-MAN-SPH-14690-0430 P104.0 </tt>
</ul>



This plot shows the resolving power of the IFS arm for both prism JY
and JYH.  Of the up the four available laser arc lines, only the resolving
power (R = lambda / delta lambda, where delta lambda is the FWHM) of the
1.1237 mu laser (respow2) is shown. The pipeline cube product is median
collapsed in both spatial directions (border regions are omitted) and the
resulting arc spectrum is analysed via a Gaussian fit to each of the 3-4 the arc lines.

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The resolving power is specified in the TLR documents to R=15, while
the IFS arm performs better at (long-term average): 39.7 (YJ) and 25.6
(YJH), which are used as reference values in the KPI plot.