Half a croissant, on a plate, with a sign in front of it saying '50c'
h a l f b a k e r y
Tip your server.

idea: add, search, annotate, link, view, overview, recent, by name, random

meta: news, help, about, links, report a problem

account: browse anonymously, or get an account and write.

user:
pass:
register,


                                                                 

Flying, automated sextant

Let the drone handle those measurements!
  (+4)
(+4)
  [vote for,
against]

If there is one thing that just isn't much fun, it's trying to shoot a noon sight on a rolling deck with a sextant. So why not automate the process?

With a small station keeping drone, a sextant reading could be performed at a stable elevated position above the sea by a multi-eyed computer, then all calculations would be finished by the time it returned to the deck of the boat. More accurate than a hand-reading from a tossing ship, with more reliable results. No more shooting the sights and trying to look up the reference books before running the calculations. Also, this could work with both sun sights as well as star positions at night. Heck, with the right lens you could see some star positions during the day or even catch a sun position on a cloudy day!

An excellent back-up for GPS (or protection against spoofing), especially if combined with an inertial guidance system; then you too could have the self-contained navigation powers of a warship.

unhelpful_fool, May 26 2019

Nortronics NAS-14V2 Astroinertial Navigation System https://www.reddit....14v2_astroinertial/
How to navigate by the stars when the Sun is up [notexactly, May 26 2019]

Wikipedia: Sunstone (medieval) https://en.wikipedi...Sunstone_(medieval)
How to navigate by the Sun when the clouds are up [notexactly, May 26 2019]

More photos of the first thing https://timeandnavi...l-navigation-system
Because I'm sure it will be found interesting [notexactly, May 26 2019]

More info on the first thing https://www.thedriv...denied-environments
And on a bunch of related things too [notexactly, May 26 2019]

What is actually happening here. https://en.wikipedi...elestial_navigation
Celestial navigation [unhelpful_fool, May 26 2019]

[link]






       I would use this!   

       Not sure what for.
pocmloc, May 26 2019
  

       Hey, [unhelpful_fool], welcome to the HB!
MaxwellBuchanan, May 26 2019
  

       It would need some high grade stabilization, but an interesting idea.
8th of 7, May 26 2019
  

       Isn't stabilization the point of using the drone?
notexactly, May 26 2019
  

       [MaxwellBuchanan], Thanks! Glad to be trying my hand at a bit of baking.
unhelpful_fool, May 26 2019
  

       [notexactly], I appreciate the links, those were some of the bits that I was reading before posting. Well, not the sunstone one; but that was still neat.   

       Although stabilization is difficult, I can't see it being all that much worse than the average sailor pulling out their sextant. Or the subsequent math skills necessary for actual plotting. Having a computer handle it from start to finish would probably end up with more accurate results.
unhelpful_fool, May 26 2019
  

       Hi, UF. Welcome to the bakery. I am so glad you are here. Your idea has left me just as completely clueless as 99% of all the rest of the ideas. I'm used to it. I don't have any idea what-so-ever, what it is. But that is my norm.   

       Thankfully "two cups of coffee" was kind of selfexplanatory. I got that one, I think that was the last one. Hahahaha   

       P.S. Don't worry about the "unhelpful or fool" thing. Those qualities go far around here.
blissmiss, May 26 2019
  

       How will the drone keep station on the vessel ?   

       It can be quite windy at sea, and it is reasonable to assume that the launch platform is moving. So the challenges are:   

       Taking off from a moving platform in windy conditions without hitting any of the bits of the ship.   

       Getting a stable horizon and sun sight.   

       Landing again (previous difficulties apply).   

       Landing a helicopter on a ship is non-trivial (presuming you wish to (a) survive, and (b) use the helicopter again without extensive repairs), and they have a lot more inertia than a drone.   

       Oh, and welcome to the hb. There is a help file (which contains useful advice such as "What to do if the straps on your straitjacket are too tight"), but don't worry about doing things wrong as the regulars will immediately assemble, waving agricultural implements and burning torches, and explain your errors as the bonfire piled around you starts to burn.   

       Trvial transgressions such as poor spelling or grammar are punished mercilessly. The toilets are over there, the kitchen is up the stairs on the left. Please leave trash out for collection on Thursday evenings. If you use the torture implements or the lawnmower, you are expected to clean off any blood or tissue and leave things tidy for the next person. The nailed-up wooden crate with the yellow fangs chomping at the airholes contains [xenzag] . Don't get too close, and if you are bitten it's important you get medical treatment quickly. The venom is not toxic to humans but deep incised wounds are prone to infection.
8th of 7, May 26 2019
  

       But, for that very reason, a drone is better able to respond to sudden squalls or unpredictable movements of the ship. Assuming that wind-speeds don't exceed the drone's maximum airspeed, I'd wager that it could land automagically on any ship.   

       [bliss], let me maxsplain it for you. He's basically talking about using the differential angle on the solar tangent, coupled with taking reciprocals from the horizon against the lunar parallax. I mean, that's a bit simplified, but you get the idea.
MaxwellBuchanan, May 26 2019
  

       And if that doesn't work, try launching from a catapult and landing in a net.
notexactly, May 26 2019
  

       [8th of 7], The nice thing about astro navigation is that it really isn't that precise and boats don't usually go that fast, so station keeping becomes much simpler. The drone could stabilize and take a shot up to a hundred meters away and still be mostly accurate considering how inaccurate the total system is.   

       I'm not an expert, but it seems like a computer would be faster/more responsive to landing on a moving boat. Especially if it's a small sextant sized drone. Heck, you could attach a line and reel to the drone and launch it like a powered kite from the downwind side of the boat. Then just reel it back in for retrieval.   

       Thanks for the welcome!
unhelpful_fool, May 26 2019
  

       OK everyone. We've lulled him into a false sense of security. Remind me what Step 2 was?
MaxwellBuchanan, May 26 2019
  

       Welcome and [+]
Voice, Jun 07 2019
  

       Was the custard in step 2 or step 14?
Voice, Jun 07 2019
  

       Both.   

       One question, though. If the drone is station-keeping, does it not require GPS? And if so, is this not a redundant solution?
MaxwellBuchanan, Jun 07 2019
  

       It could home on an RF or optical beacon on the vessel.   

       Traditionally the custard comes between the waterboarding and the termites, but it could just as easily be put in after the electric shock treatment. But for the full effect it needs to be at least three steps away from the Yoghurt Room.
8th of 7, Jun 07 2019
  

       That can't be right. Custard is one of the things you can feed to captive numbats when they *can't* get termites. If you're storing the custard next to the termites, that's just asking for trouble. Where is the numbat, anyway?
pertinax, Jun 07 2019
  

       It's [po]'s turn to look after it this week.
8th of 7, Jun 07 2019
  

       Hang on, hang on... [unhelpful_fool] appears to have escaped! Fetch the bloodhounds!
MaxwellBuchanan, Jun 07 2019
  

       They're off duty. We'll send the anteaters.
8th of 7, Jun 07 2019
  

       Oh great. I didn't even realize they'd finished maiming [treon]. Having them de-clawed and only leaving the teeth was frankly a mistake. How long does it take to moisten someone to death?
MaxwellBuchanan, Jun 07 2019
  

       All right, hang on a minute ...   

       <rummaging in box/>   

       There's a couple of wallabies ... OK, so one's got a touch of asthma, and the other is on meds for arthritis ... admittedly they don't look very threatening ...   

       <rummaging/>   

       <muttering> ... never wanted this job, wanted to be a steam engine driver ... ...<muttering/>   

       Capybara ? Got a capybara ... give you a nasty nibble ...   

       <rummaging/>   

       Got lots of cane toads, poisonous if you eat 'em ... any good ? Or there:s a sloth ... at least, there was - seems to have wandered off ...   

       What about a vampire bat ? Can let you have the vampire bat, just need to find his dentures.
8th of 7, Jun 07 2019
  

       Have we already sent Piers Morgan off to Chester Zoo for the breeding program?
MaxwellBuchanan, Jun 07 2019
  

       Yes, but breeding ? We understood he's to be exhibited in the reptile house, with all the other scaly, cold-blooded venomous predators.
8th of 7, Jun 07 2019
  

       That's what we told him too. Wait 'til he meets the giraffe.
MaxwellBuchanan, Jun 07 2019
  

       //reptile house//   

       sp: House of Lords
Voice, Jun 07 2019
  

       [MaxwellBuchanan], The station keeping can be as simple as a black and white grid pattern on deck which is visible from the air. You wouldn't worry about operating in rain and low visibility because you can't see the sun/horizon at those times in any case. A radio beacon could work, as [8th of 7] pointed out; but not necessary unless the drone is going to fly above fog/clouds for a positioning shot.
unhelpful_fool, Jun 14 2019
  
      
[annotate]
  


 

back: main index

business  computer  culture  fashion  food  halfbakery  home  other  product  public  science  sport  vehicle