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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Here the article was looking for months ago found today.

It was 2016 and reprint in 2024

Dave
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"Raise your hand if you have ever determined your location on the planet using the stars," Lt. Daniel Stayton tells his class at the U.S. Naval Academy.
A young officer halfheartedly puts up her hand. Another wavers. The rest of the class of 20 midshipmen sits stone-faced.
This is the challenge facing the U.S. Navy as it tries to bring back celestial navigation. The Navy stopped training its service members to navigate by the stars about a decade ago, focusing instead on electronic navigational systems. But fears about the security of the Global Positioning System and a desire to return to the basics of naval training are pushing the fleet back toward this ancient method of finding a course across open water.
Navigation by the stars dates back millennia. The ancient Polynesians used stars and constellations to help guide their outrigger canoes across thousands of miles of the Pacific Ocean. And right up until the mid-20th century, navigation on the sea was usually done by looking at the heavens.
That changed in the late 1970s, when the military began launching GPS satellites. The satellite system provided a far more accurate fix than the stars could. In 2000, the U.S. Navy began phasing out sextants and charts in favor of computers.
Rear Adm. Michael White, who heads the Navy's training, says the change in curriculum was driven by the need to bring young officers up to speed on the Navy's equivalent of Googlemaps, called the Voyage Management System. It uses GPS, radar and other tools to precisely track a ship's position and course across the ocean. The system is complex and, "we don't have infinite training time available," White says.
spaceclass-1-21c72e698e43f18ad793c48589046c63492f5204.jpg


Lt. Daniel Stayton demonstrates how to use a sextant before a class of midshipmen at the U.S. Naval Academy.
Geoff Brumfiel/NPR
So, why return now to the old ways? The Navy and other branches of the U.S. military are becoming increasingly concerned, in part, that they may be overly reliant on GPS. "We use it to synchronize all military operations, we use it to navigate everywhere — it's just something the U.S. military can't live without," says Brian Weeden, a former Air Force officer now with the Secure World Foundation, a nonprofit that studies security issues in outer space. In a big war, the GPS satellites could be shot down. Or, more likely, their signal could be jammed or hacked.
Already, jamming has become more common, Weeden says. "You can buy a lot of GPS jammers off the Internet," he says. "A lot of those are made by Russia."
He thinks the Russians probably have systems to jam the special signals the military uses as well. And China may be developing similar capabilities.
White, who heads the Navy's training, says there is also a desire to get back to basics. Over the past decade, electronic navigation systems on ships have become easier to use, so less training is required. He says the Navy is bringing back celestial navigation to make sure its officers understand the fundamentals.
"You know, I would equate it to blindly following the navigation system in your car: If you don't have an understanding of north/south/east/west, or perhaps where you're going, it takes you to places you didn't intend to go," he says.
In fact, there has been at least one incident in the past decade when a Navy ship ran aground partly because of problems with the electronic navigation system, investigators say.
Back in the classroom at the Naval Academy, the midshipmen finishing up their first course seem a little bewildered. Until now, says 20-year-old Audrey Channell, celestial navigation wasn't on her radar.
"I mean, obviously I heard about using stars to navigate in the old days," she says, "but I never thought I'd be using it."
Like many of the others in the class, she uses GPS to navigate her daily life.
Her instructor, Daniel Stayton, says that's OK. Nobody expects these young officers to become Magellans overnight.
 

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