NavList:
A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Wayfinding
Re: Sextant accuracy and possibility of future improvement
From: Lu Abel
Date: 2016 Jul 21, 17:27 +0000
From: Lu Abel
Date: 2016 Jul 21, 17:27 +0000
Once again not addressed is the stability of the platform and observer. What good does it do to have an "electronic inclinometer" with "sub second accuracy" when the observer is using this electronic sextant to take shots from the deck of a rolling vessel? Or when he or she can not hold the sextant to a sub-second steadiness?
If you want an example of how hard it is to achieve exact levelness, I suggest downloading the free smart phone app "Theodolite" Using just the basic capabilities of a smartphone it gives an indication of how level you are holding your phone in both the fore and aft and sideways directions. And how those readings bounce around as you attempt to do your best possible job of holding your phone steady.
From: Philip Lange <NoReply_PhilipLange@fer3.com>
To: luabel@ymail.com
Sent: Thursday, July 21, 2016 7:13 AM
Subject: [NavList] Re: Sextant accuracy and possibility of future improvement
If it can be mounted as an after-market accessory, Paul, I want one! Just think - shooting stars anytime they are visible! The moon or any body with or without a visible horizon. Build it and i will buy it!
On 07/21/2016 12:33 AM, Paul Dolkas wrote:
I always thought that the biggest problem with sextants (especially the aircraft bubble type) was the problem of figuring out where horizontal is. So why not replace the liquid bubble with an electronic inclinometer? They are now readily available reading down to sub-second accuracy. It could either be attached to the index mirror for a direct readout of elevation, or attached to the horizontal “base” with a rotary encoder to figure the elevation from there. You sight the star, push the button, and you’re done.
