GONG Hα Filter Repair Update

 An update on the repair of four of GONG's filters was received from Daystar Filters on May 19th.

The company owner, Jen Winter writes:

" I have good news to report.  We have completed all of the lab work on all four of your filters in now for service. We ultimately had to build a new optical workstation which includes a Shack-Hartmann test rail at the actual optical production bench for interactive feedback during each layer of the optical rebuild process.  This gives us rapid iteration of technique variation, which revealed processes which correct the optical figure within the filter. The filters are all optical figure, wavelength and CWL-uniformity tuned. However, we haven't had them out for live sun testing as we always do just as one last sanity check."

 The image on the left is a degraded Hα image from Learmonth. This filter was removed from service on 8/31/22 and is one of the four filters being repaired.

The filters should be back in Boulder by the end of May. They will undergo a lab inspection and then testing at the Boulder engineering shelter "TE".