View Single Post
  #5   Report Post  
posted to rec.boats
John H.[_5_] John H.[_5_] is offline
external usenet poster
 
First recorded activity by BoatBanter: Jul 2008
Posts: 8,663
Default celestrial navigation

On Tue, 27 Oct 2015 09:25:11 -0400, wrote:

On Tue, 27 Oct 2015 08:23:08 -0400, John H.
wrote:

On Mon, 26 Oct 2015 20:34:15 -0400,
wrote:

On Mon, 26 Oct 2015 16:52:26 -0700, Califbill billnews wrote:


Bringing it back.
http://www.latimes.com/nation/la-na-...025-story.html

I understand at the academy level you want to teach the traditional
course. Would they still want the fleet doing it this "old school"?

Now the question becomes, will they still use the almanacs on paper or
on a small tablet with a calculator? Perhaps they would use something
with a burned ROM so it can't be hacked or corrupted. These days a
small device could carry 100 years of almanac data and be able to do
all the calculations directly from the observations. It could even
have a tutorial and a star finder for guys who get rusty.
That would give you the ease of electronic help and the reliability of
looking at stars.
With the right interface, it could just be a "fill in the blanks"
thing.


Quick, someone call Intel!


My wife has an app on her iPad, 'Star Walk'
(http://vitotechnology.com/star-walk.html), which enables her to identify stars.
Pretty cool.


Android has something similar. You just hold your phone up and it
orients and lays the stars out. The problem is, it is GPS driven so if
GPS was down, it would be down.
OTOH if you knew the time and date, located Polaris and matched the
other stars you could get a rough idea of your longitude. Get the
angular height of Polaris and you get your latitude. (northern
hemisphere)
Using a sextant to hone in on those angles, is basically celestial
navigation


Hers uses an onboard GPS also.
--

Ban idiots, not guns!