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Back in the 1930s, -40s, -50s, -60s & -70s (before INS [now GPS] became standard), most passenger airliners (& military operators - heck, even on NASA Apollo missions!)) used an optical periscope in the cockpit/flight deck in order for the navigator (they had them in those days!) to triangulate position based on star sightings.
I don't believe this skill is taught nowadays, but they certainly relied on stars visible at night for localisation.
The process was essentially the same as we use even today for star alignments, but in reverse (i.e. determine Alt/Az of known stars in flight & triangulate), and without the benefit of computers!
Dean
Last edited by deanm; 20-02-2016 at 05:02 PM.
Reason: Detail
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