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> Of course, celestial navigation doesn't work in the daytime. Even with a simple sextant you can use the sun. And the SR71's system did operate during daytime
by the8472 8y ago
> Of course, celestial navigation doesn't work in the daytime.
Even with a simple sextant you can use the sun. And the SR71's system did operate during daytime using starlight.
- deleted 8y ago[deleted]
- ams6110 8y agoI was wondering about that. I guess at the altitudes the SR71 operated at, at least the brighter stars would be visible.
- the8472 8y agoThey don't have to be visible to the human eyes, just visible to instruments. With band filters and a narrow field of view you can get a stronger signal that sticks out from the the approximately uniform sky background. I mean the altitude helps, but it's not necessary.