AstroNav - using a calculator or laptop

smartcom said:
The laptop is generally easier to use than a calculator, and can be used for many other tasks, but obviously is bigger and draws more juice. However our WinAstro software (www.winastro.co.uk) was used by most of the boats in the last Volvo as part of their mandatory backup system for a sextant fix - saving the weight of the almanac and sight reduction tables!
Tim
Click to expand...

Thank you Tim for posting something relevant. To the rest of you, please stop telling me to 'just persevere' - I have wasted enough of my time on this already and will not be pursuing it unless I have a very strong suspicion that the GPS system is permanently doomed. On ocean passages we carried - and will again - an emergency astro-nav book that would see us through in the event of total loss of all electronics including hh devices, but in most circumstances a calculator or laptop would be prefereable.

No-one has suggested an affordable calculator-based solution, so I guess there isn't one. It's a shame calculators don't run javascript. Re. Winastro - an idential javascriopt based application is available free, but in fairness to Tim I will not post any links to it here. Winastro is very reasonably priced and comes with support, so I reckon it is a good buy.

- W
 
Last edited:
webcraft said:
No-one has suggested an affordable calculator-based solution, so I guess there isn't one. .

- W
Click to expand...

Webby,
There are many solutions based on programmable calculators. The one I am familiar with I came across in the Almanach Breton - How to program a Casio.
I haven't got the book to hand - can't remember if it's here or in France, but I'll have a look and get back to you.
 
It should be possible to write a suitable app for mobiles these days though I doubt any of the mainstream authors would be bothered with anything this specialist.

I have an Excel spreadsheet downloaded from a helpful forumite that lets you put in your time, CP and sextant reading and gives you the intercept. Would you like a copy?
 
snowleopard said:
It should be possible to write a suitable app for mobiles these days though I doubt any of the mainstream authors would be bothered with anything this specialist.

I have an Excel spreadsheet downloaded from a helpful forumite that lets you put in your time, CP and sextant reading and gives you the intercept. Would you like a copy?
Click to expand...

I wouldn't mind a copy if you are willing.

Thanks
 
webcraft said:
On ocean passages we carried - and will again - an emergency astro-nav book that would see us through in the event of total loss of all electronics including hh devices, but in most circumstances a calculator or laptop would be prefereable.

No-one has suggested an affordable calculator-based solution,.....

- W
Click to expand...

Cdr Harry Baker's 'Reeds Astro Navigation Tables' for the current year, at £16.99, is a 68-page A4 booklet from Adlard Coles Nautical which is lighter, smaller and much more convenient on a small craft than the heavy and expensive Nautical Almanac ( or Air Almanac ) plus AP3270 Sight Reduction Tables.

It permits an easy 'look up' approach, which also requires a proforma and a chart-table. Within the book is a small section on 'Formulae for Scientific Calculators', which would achieve a fair part of what you seek, I suspect.

Additionally, Harry Baker used to offer a programmable calculator with the various 'works' already programmed in. I have one, somewhere within my mountain of old-generation anchors, worn-out oilies, spare coils of warp, Harken Traveller Cars, half-a-dozen lifejackets, assorted shackles, clevis pins and s/s 1X19, which worked the last time I went out of sight of cloud with my Royalty-gifted sungun.

If you really, really want - and after having a satisfactory peek at Harry Baker's publication ( I know you're a long way from a civilized and well-stocked chandlery, and the WH Smiths in Oban certainly doesn't stock this ) - PM me and I'll dig the device out and post it to you.

There!

:)
 
Lady Campanula said:
Cdr Harry Baker's 'Reeds Astro Navigation Tables' for the current year, at £16.99, is a 68-page A4 booklet from Adlard Coles Nautical which is lighter, smaller and much more convenient on a small craft than the heavy and expensive Nautical Almanac ( or Air Almanac ) plus AP3270 Sight Reduction Tables.

It permits an easy 'look up' approach, which also requires a proforma and a chart-table. Within the book is a small section on 'Formulae for Scientific Calculators', which would achieve a fair part of what you seek, I suspect.

Additionally, Harry Baker used to offer a programmable calculator with the various 'works' already programmed in. I have one, somewhere within my mountain of old-generation anchors, worn-out oilies, spare coils of warp, Harken Traveller Cars, half-a-dozen lifejackets, assorted shackles, clevis pins and s/s 1X19, which worked the last time I went out of sight of cloud with my Royalty-gifted sungun.

If you really, really want - and after having a satisfactory peek at Harry Baker's publication ( I know you're a long way from a civilized and well-stocked chandlery, and the WH Smiths in Oban certainly doesn't stock this ) - PM me and I'll dig the device out and post it to you.

There!

:)
Click to expand...

Mlady,

Thanks for the info, duly noted and filed. Re. the calculator, do you know the make and model? I actually bid on one today on ebay (.com) but then looked it up and discovered that even with creative tweakery it could not be persuaded to function beyond June 23rd 2007!

(Twas a Tamaya Astro Navigation Calculator NC-2, but the N77 has the same almanac)

- W
 
Last edited:
My dear old Webby,

I was about to reply that I'd have a hunt for my 'prog-calc' sometime, tomorrow, perhaps... for I had the feeling in my water that, like most things I'd put away so I can find them again, it would probably take days of digging and swearing and ferreting out and 'what's this doing in here' and.....

Anyway, I found Harry Baker's 'Step-by-Step Guide' booklet on the right shelf, in seconds! Unprecedented....!
Emboldened a tad, I had a root through several small drawers stuffed with bit 'n bobs, and there it was - the calculator. Two of them, actually. Not quite unprecedented, but very nearly. See above.

'Old Harry's' is a Casio fx-3900PV, still in its box. The other one is a Tandy EC-4024, which is very similar to the Casio, except it has an early little 'solar panel' to help keep the 'lecky flowing when needed. And now I remember that was my answer to corroding AA cell terminal corrosion.

I'll scan the Guide into a .pdf file and forward it to you, if you'd PM me with an appropriate e-address. ( I should remember, but right now the brain's like molasses ). That way, you may consider whether this approach would suit your preferred way of working.

I remember, some years ago, lusting after the Tamaya calc-instrument but being quite unable to afford one. The value is in the stored ephimerides - or the algorithm for calculating said stuff. I've no idea whether the device on eBay is still able to 'produce the goods', or whether Tamaya could supply an upgrade, but I'm tempted to think that such things have come on mightily since the late 20th Century, and your money could be better spent elsewhere, like on a USB pendrive and a couple of portable apps. But that's not for me to debate....

:)
 
snowleopard said:
It should be possible to write a suitable app for mobiles these days though I doubt any of the mainstream authors would be bothered with anything this specialist.

I have an Excel spreadsheet downloaded from a helpful forumite that lets you put in your time, CP and sextant reading and gives you the intercept. Would you like a copy?
Click to expand...

Don't think it'll run on a Windows CE device. I'll see if I can write a simpler, macro free, version for portable devices that run the CE version of Excel. (need to buy myself such a device to test it though!)

The files are here :)
http://www.4shared.com/dir/31216587/ad3b16e1/sharing.html
 
Last edited:
ive just got a new sextant and my reason behind it was to have it as a fail safe system and insurance against my electronics going down.

I found an E-Book called Sextants for the Clueless,it takes a lot of the geek speek maths out of it and brakes it down to straight forward high school level maths.

i shall resist buying an electronic device for doing the calcs
 
Sunsight spreadsheet

I've just uploaded a lightweight version of my sunsight reduction spreadsheet. It's only 42kb and is free of macros.

I'd be interested to hear from anyone if it will run okay on a portable device running pocket Excel. I can't test it on a PDA as I'm stuck out on a rig, off Tunisia, for a few weeks (where it's raining).

The spreadsheet gives you the same info you get from tables: GHA, Dec, LHA, Hc and Ho, then Azimuth and Intercept.

The file's called SunsightLite.xls and you can find it here:-
http://www.4shared.com/dir/31216587/ad3b16e1/sharing.html

Andy
 
Last edited:
This is more of a moan than anything , but I've always used a simple scientific calculator and punched in the numbers for the spherical cosine formula for doing the basic sight and then used abc tables for the azimuth. My moan relates to modern calculators which I find to be a complete pain in the @@@. The old ones essentially allowed you to use whatever number was in the display and if you wanted the cos or sin of it you just pressed cos or sin or whatever, now you have to put it into a memory then press cos or sin and then bring it out of memory which is so ridiculous it makes you want to cry. I was so cross I ended up buying an HP at huge expense which uses reverse osmosis or something as a operating logik and it would be brilliant except that it doesn't manage to do degrees minutes and decimals of a minute. You can get around it by doing degrees and so many hundreds divided by 600 thereby fooling it but I'm amazed that it can't manage degrees and minutes when even the cheapest of chinese calculators can do that. There is a perverse pleasure in having the HP which people not in the know are unable to make work. Am I the only one who hates these modern calculators. I wish I still had my old Casio fx which was beautifully predictable.
Moan over.
 
You must log in or register to reply here.

Other threads that may be of interest

N
Integral Battery Electric Outboards… with MORE POWER!
Replies
11
Views
742
ontheplane
O

Share this page

Top