Sextant App

[Idaho]

Is there an android app where you input the observed sextant angle and the time, then the app outputs the lat/long?

To calculate the solution, it needs no Internet, no cell tower, no GPS sats. Just the app, the sextant, and the time.

[Adelie]

Ask this question at Navlist, URL in my signature.

Keep in mind that CelNav accuracy is on the order of 5-10nm depending on equipment and stability of what you are sitting on.

[double u]

Originally Posted by Idaho

Is there an android app where you input the observed sextant angle and the time, then the app outputs the lat/long?

To calculate the solution, it needs no Internet, no cell tower, no GPS sats. Just the app, the sextant, and the time.

...it is a rare occasion, when ONE observation gives you your position...very rare...
...celestial is not for you!

[goboatingnow]

There are IOS apps that will do the sight reduction calculations for you and you then draw the resulting line of position on the paper chart , there is one app that lets you compute multiple sights on its own map and in theory you can extract a position

Half the fun is do it by hand but it’s easy to make simple adding and subtracting mistakes , I use my own paper worksheet that prevents me from going astray.

So yes it’s possible to various degrees of applicability , either sun-run-sun or full star sight reduction

[Rumrace]

Sextant doesn’t work that way but sound cool. Sextant gives you latitude your Grandson does the fast math to estimate longitude.
Another cool app is three random words. A random 3 word phrase was added to every square meter on earth. It’s saved lives.

[Rumrace]

There are instructions on Pinterest on how to make a sextant with two mirrors 2 Lego bricks and a discarded CD. Works too. Keeps the young ones busy with glue guns and creative thinking. Gives them a keen understanding of “are we there yet”

[JC Reefer]

I dare say, if you have a working device then you could used the built in GPS to locate your position.

Yes, the satellites need to be working but No cell service needed.

I know that’s not your point but…

[goboatingnow]

Originally Posted by Rumrace

Sextant doesn’t work that way but sound cool. Sextant gives you latitude your Grandson does the fast math to estimate longitude.
Another cool app is three random words. A random 3 word phrase was added to every square meter on earth. It’s saved lives.

Clearly you have never used a sextant and taken three star fixes , reduced them and plotted lines of position , a sextant gives you fixes from known stars just like a land based fix gives you lat and long

[goboatingnow]

Originally Posted by Rumrace

There are instructions on Pinterest on how to make a sextant with two mirrors 2 Lego bricks and a discarded CD. Works too. Keeps the young ones busy with glue guns and creative thinking. Gives them a keen understanding of “are we there yet”

Sounds very precise and those resulting lines of position might give you 100 mile accuracy

Of course the sight reduction tables , not sure where the “ young ones “ will get those

A good sextant is a very precise instrument by the way.

[JC Reefer]

Originally Posted by goboatingnow

Sounds very precise and those resulting lines of position might give you 100 mile accuracy

Of course the sight reduction tables , not sure where the “ young ones “ will get those

A good sextant is a very precise instrument by the way.

Pretty sure he was not endorsing it for practical use. It’s why he mentioned the kids… because it’s a toy.

[ItDepends]

Originally Posted by Rumrace

Sextant doesn’t work that way but sound cool. Sextant gives you latitude your Grandson does the fast math to estimate longitude.

What???? Sextant and clock most certainly gets you lat and long.

[tkeithlu]

Harald Merkel's Celestial Navigation app gives you a line of position given your sight and the parameters you entered, and draws it as a line from your assumed position. It does the entire job. But then, that takes the fun out of it.

I use it for practice with the sight side of the task - entering my known position from GPS and then seeing how close I can come to that with a Sun sight. I should do the hand calculation as well and see if I get a match.

[ItDepends]

Originally Posted by JC Reefer

I dare say, if you have a working device then you could used the built in GPS to locate your position.

Yes, the satellites need to be working but No cell service needed.

I know that’s not your point but…

Unless you have a particular type of paranoia, the failure of the satellites is not the issue. Failure of electronics aboard from a lightening strick most certainly IS.

Every sailboat on the ocean is one lightening strike away from the 19th century. If you were 1000 NM from land at that point what would YOU do???

[goboatingnow]

Originally Posted by ItDepends

What???? Sextant and clock most certainly gets you lat and long.

There ate several methods of sextant navigation

Marc Hilare where azimuth fixes are taken from celestial bodies and lines of position ( aka fixes ) are plotted. Lat Lon is then deduced by their intersection.

Meridian passage of the sun , good accurate time is needed here.

Sun-run-sun , aka standard running fixes.

There are also more obscure other methods as well.

[Rumrace]

For some folks arguing is their fun.