Astro calculator

[Graham_Wright]

I have finished Tom Cunliffe's book on astro and found it straightforward.

I see no problem with the arithmetic but it is a bit ponderous.

Is there an app or an appropriate calculator that would do it for me?

Perhaps together with the almanac.

 

[GHA]

The opencpn astro plugin is worth a look, though just been having a play, seems that you put in computer time rather than UTC.
Gives you LOP on the chart.

https://opencpn.org/wiki/dokuwiki/d...anual:plugins:navigation:celestial_navigation

 

[ghostlymoron]

The whole point of astro is not to be reliant on electronic gadgets (or you might as well use GPS ). This must include any sort of calculator so that you can continue to find your position if your electrics are all defunct. Besides which, during an ocean crossing, there's a lot of free time and not much to do so you might as well spend it reducing sights and exercising your brain. I learnt astro as part of the Yachtmaster Ocean course and enjoyed doing it but have not used my knowledge since although I've bought a sextant.

 

[sarabande]

Quite a number of clever programs available at PC, tablet and phone level.

https://duckduckgo.com/?q=sight+reduction+calculator&t=ffab&atb=v69-7&ia=web

Casio used to have a dedicated handheld calculator, but I haven't seen one on ebay for a year or so. IIRC Tamiya also made one for the Japaneses Navy.


FWIW I use LunaSolCal and Sky Map on an android phone for base data. I must have got through several trees using Marc St Hilaire intercepts many years ago.


Aha, I knew we had been here before

http://www.ybw.com/forums/showthread.php?199589-Sight-reduction-by-pocket-calculator

 

[GHA]

The whole point of astro is not to be reliant on electronic gadgets (or you might as well use GPS ). This must include any sort of calculator so that you can continue to find your position if your electrics are all defunct. Besides which, during an ocean crossing, there's a lot of free time and not much to do so you might as well spend it reducing sights and exercising your brain. I learnt astro as part of the Yachtmaster Ocean course and enjoyed doing it but have not used my knowledge since although I've bought a sextant.

He can do the sums, so not reliant on a gadget.

A calculator can be extremely useful when learning as you get instant feedback on the sight without having to go through all the calcs and plotting then there's the suspicion that the calcs are out when the LOP is way off.

Then with a bit mode confidence in sight accuracy you can practice the maths/plotting. No point trying to learn it all at once when you don't have to.

The opnecpn plugin gives nice LOPs as well you can zoom in and out of which helps visualizing what's going on.

 

[duncan99210]

Not going to get into the philosophy of doing it all steam driven and books but I’ve used the ezSights app on iPad to do the skull work. It includes an almanac as part of the suite which also include lunar calculations. The app give the ability to use it simply as an almanac or to do the whole job, you just give it the sight data or anything in between.
It’s a good app for the beginner as it give instant confirmation or otherwise that you’re getting the sextant work right. You can then turn off the automatic bits as you gain confidence, doing all the work on paper if that’s what you want, just using the almanac.

 

[capnsensible]

I find it harder to mess about using appy stuff, keyboard clattering and general computer angst rather than just doing a bit of adding up and taking away......

On the plus side, T. Cunliffe book is very good, his pro formas are easy. See also Tim Bartlett Astro book. That has the best description of the planet diagram in the almanac ever.

For those who love the one and zero, there is an alternative way of sight reduction in the Nautical Almanac. Even I will grudgingly agree that a calculator is handy for that. I can waste hours trouble shooting that method!

Question for GHA have you tried that one, seriously think it would appeal to you, it has a certain mathmical challenge to it.

 

[capnsensible]

Mathematical. Corrn.

 

[tjbrace]

Have a look at this site. Simplified tables and spreadsheets. http://www.backbearing.com/

 

[Graham_Wright]

Have a look at this site. Simplified tables and spreadsheets. http://www.backbearing.com/

I was thinking around a spreadsheet. I am sure there is a tremendous kick to be obtained by an astro fix that is somewhere near what the sats tell us. There is probably another kick when the spreadsheet results tie in with the manually calculated ones.

I've downloaded the Backbearing one.

Now I need a horizon!

(Why won't a pendulum work?)