GPS COMPUTER VS SEXTANT/ASTROLABE/Old ways/manual

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This was just deliver without modification by the Postoffice.
Only took three trys free shipping from Amazon

IIdea of size on the old laptop
Sextant Mar14 2025.jpg


Front side
Sextant Mar 14 2025 2.jpg

Back side
Sextant Mar 14 2025 5.jpg



The sextant is great for low price.
The main down side is fine calibration.
You just loosen a screw and move the horizon mirror.
The high end sextant has fine adjustments screw.


List of things I am doing or may do

1) This a item I making draws to add this to sextant.
2) Since live near the ocean I am thinking of adding a bubble level not found on almost all sextant today.
4) Improving the handle and adding a camera tripod mount.
5) Adding a LED to veneer for easy read
6) The last is adding a Optical and Improving the filters. The photo show what looks like optics but clear plastic.


It a lot cheaper to buy and modify less time over building from scratch.
I was going build from scratch till saw what going to cost for materials and complete one is only $21.99 and mostly done ⁰or almost $75.00 for materials
Screenshot_20250316-224148_Amazon Shopping.jpg

Dave
 
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WHAT DO YOU THINK ?

Here some more on accuracy I found on internet. Just little more information.
The
theoretical accuracy is harder for calculations and most websites try very hard to sell book or courses. Remember they did with a Astrolabe about 1° and table located on the Astrolabe. By 1960’s we taking in the slight deflection of the atmosphere on a 3 digit sliderule. Give more time and you would taking the temperature of waster to still be about close as the Astrolabe with veneer 15 minutes or 17 miles.
The GPS is hard to bet 40" [3 meters] but real time using 10 miles [16 KM] {8.6 NM} is good for navigation on the open ocean.


Dave



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{{{{ The theoretical accuracy of celestial position fix is within 0.1 mile of your true position. In comparison, a modern GPS should be able to give you an accuracy of less than 1 meter. A GPS fix is at least 100 times more accurate than a celestial fix

How Accurate does a Celestial Fix need to be?​

Not very accurate at all.

Celestial navigation is used when you are far out at sea, when no other methods of position fixing are available.

If you are hundreds of miles from the nearest land, 10 miles of error in your position is not too significant.

Remember, in the middle of an ocean, you will be using a small scale chart. The chart probably covers most of the ocean }}}}
 
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