Subject: Solar Flux Smoothing's Affect on ISS Drag Modeling
From: Daniel Adamo <[email-masked]>
Date: Sat, 13 Sep 2025 16:31:02 -0700

ATIG Members-

I started working on the attached paper in June 2025.  Enough pertinent data have now accumulated to warrant publication.  The big takeaway is solar flux smoothing over 13 months is excessive for values that are to be updated on a monthly basis in the course of ISS ephemeris maintenance.  Smoothing over the month preceding the update appears much more appropriate, particularly near extrema in the 11-year solar activity cycle.  As always, comments on the attachment are welcome.

-Dan