The full title is:
> An Algorithm for Affordable Vision-Based GNSS-Denied Strapdown Celestial Navigation
Emphasis mine.
In what kind of context do you expect drones to operate in an area where GNSS is disabled by electronic warfare devices? Do you really think that a $400 cost is of any issue for military use?
> Do you really think that a $400 cost is of any issue for military use?
If your name is Ukraine then yeah. Effectively halves the number of drones you can build