NavList:

Brad you wrote: My objective these past few weeks has been to find a rationale for CN.  I have been poking at every possible cause I can think of to provide a case for CN, looking for failure modes in the GNSS system.  This latest line of questions with Dr. Langley has shown, to my opinion anyway, that we cannot hang that rationale on a solar event.  Suggesting that a mariner prepare and practice CN for a 'once in 500 year' event is a bridge too far.  The more recent events provided in the recommended articles suggest that CN will not be the backup, again, in my opinion.  Outages lasting 10 minutes or providing small fix errors due to propagation delays will never provide a reasonable rationale for CN.  In my view, solar events are a dead end.  I was hoping Dr. Langley, with his far better understanding of the GNSS system, would concur on those points.

Brad

Why not forget the idea of CN as a ‘back-up’ for GNSS or indeed any other electronic aid to navigation completely and simply accept that it’s great fun and keeps the little grey cells exercised.  Actually that’s not as daft as it sounds.  If my quick scan of The Times newspaper every day is correct, there are reports suggesting that sustaining metal gymnastics into old age would appear to influence ones chances of warding off dementia, or perhaps such theories are proffered more in hope than conviction.  Another possible advantage is that to have successfully used CN at some time or other improves ones confidence, self assurance, and standing as a navigator.  Could this be the subliminal reason for a quick look at CN being reintroduced into the USNA syllabus?  DaveP