Rating:

TL;DR:
1. Mean by subgrouplength 10.
2. Plot autocorrelation (selfsimilarity)
3. Group by length 96
4. Mean over all 96 long groups
5. Tresholding to get binary
6. Bin2Morse via iteratively replacing long and then shorter subsequences
7. Morse2Text via replacing subsequences

Original writeup (https://www.sigflag.at/blog/2020/writeup-angstromctf2020-noisy/).