In a war, tt would be too easy for a technologically inferior adversary to level the playing field by taking out satellites. I have read about the proposition that North Korea launch a bomb full of gravel into orbit.
GPS is super useful. GPS satellites are vulnerable. But transmitters on the moon, not so much.
I propose GPS transmitters be placed on the moon. Even if satellites all get taken out, one could use GPS while the moon was in the sky.-- bungston, Jan 02 2017 Bubble octant https://en.wikipedi...)#The_bubble_octantMany 1940s night bombers had a Plexiglass blister on the top, for taking "star shots" [8th of 7, Jan 02 2017] Decca Navigator System https://en.wikipedi...ca_Navigator_SystemWKTE [8th of 7, Jan 02 2017] Go away and read about how GPS works.
You will then realize why this is entirely impractical.
[-] Bad science.-- 8th of 7, Jan 02 2017 Dunno, with another couple of Mormons it would work. Or is that more moons, I forget.
Hang on, if your smart device has a compass and a camera it should be able to track the stars and give a very rough idea of where you are. Bit like being a bomber pilot circa 1940's.-- not_morrison_rm, Jan 02 2017 // very rough //
Sp. "usefully accurate "
With a purpose -made celestial octant, a good chronometer, and a set of navigation tables, getting a fix is just a matter of some tedious but practical spherical geometry.
<link>-- 8th of 7, Jan 02 2017 <link>-- 8th of 7, Jan 02 2017 If the moon were shattered into 24 pieces, and the pieces were all shifted into evenly spaced overlapping orbits, this could work.
There is sci-fi potential here. All the satellites have all been destroyed by the evil gravel bomb, and earth is left without any kind of navigation. A proposal to split the moon into segments might just be crazy enough to save humanity. A team of elite specialists is assembled to go bury a nuke deep under the surface of the moon, but for the plan to work, there needs to be accurate score-lines on the surface. Only the rebel farmer Bruce Willis has the necessary experience from his forty years operating tractors. A journey via rocket-ship to plough the moon so it breaks up good and we can all find our way to the shops again.-- mitxela, Jan 03 2017 Maybe the moon is too wiggly to use for GPS. But it is predictably wiggly.-- bungston, Jan 03 2017 How about a crowdsourced positioning system? Most people know more or less where they are (for instance, I am at home as I write this), so all that's needed is some sort of communication/triangulation system that automatically asks everyone nearby "where am I"?-- MaxwellBuchanan, Jan 03 2017 It could be extended to become an aid for the elderly, not only enquiring "Where am I ?", but also "Where is this ? I don't live here ...", "Who are you ? You're not my son ...", "Have I had my dinner yet ?", "Where are my trousers ? They're taking my stuff, you know." and "Whatever happened to that nice Mr. Attlee ?"-- 8th of 7, Jan 03 2017 There's an even simpler solution, come to think of it.
I've noticed that many fixed maps carry a red dot marked "YOU ARE HERE". It strikes me that such a map, if printed on paper and made portable, would be incredibly versatile.
Of course, it would not be able to show the surrounding features, since these would differ depending on which HERE you were at, and which way you were facing. But, given that the red dot would precisely mark your location, the surrounding features would be unnecessary anyway.-- MaxwellBuchanan, Jan 03 2017 I've heard that in Taiwan, every telegraph pole has its map grid location printed on it.-- mitxela, Jan 03 2017 Is that so if they wander off, the police can return them to where they belong ?-- 8th of 7, Jan 03 2017 Someone told me that geese grow on the north side of trees, so that might aid navigation.
Anyway, if all satellites were to be made of a slightly different composition of metals, then even if they get zapped in the cascade, it should be possible to use spectrography to identify them and triangulate from.-- not_morrison_rm, Jan 03 2017 //Someone told me that geese grow on the north side of trees//
No no. It's mosques. It's something to do with Mecca.-- MaxwellBuchanan, Jan 03 2017 Barnacles. Barnacles grow on the North side of ... er ... no, mosques all face towards ... er ... if it's midday, and the sun is in the West, and the geese are in the trees ... then ... you're lost. And eating those mushrooms, or what you thought were mushrooms, probably wasn't as good an idea as it seemed at the time.-- 8th of 7, Jan 03 2017 Ha, next thing you're going to say is there are no such things as barnacle geese...can't fool me that easily.-- not_morrison_rm, Jan 04 2017 LORAN was switched off? That explains a few things.
Max, I was under the impression that you being 'at home' still left considerable room for error? At least compared to the rest of us.-- AusCan531, Jan 04 2017 This idea would work perfectly if the Earth had a lot more moons-- hippo, Jan 04 2017 Well, the moon could tell you which side of the Earth you was on...
But if you put GPS on every planet, this might be a little better.-- Ling, Jan 04 2017 Better to loft them into the Earth-Moon Lagrangian points. Closer, lots of solar energy, inherent stability.-- 8th of 7, Jan 04 2017 We could always just start a global campaign to re-paint all those grid-lines. They're shown very clearly on my OS maps.-- MaxwellBuchanan, Jan 04 2017 We did sort of cover this territory in another post "Probably the easiest way is to use lasers to project the astronomical objects on the undersides of the clouds, and then control their placement so as to mirror the movement of real astronomical objects."-- not_morrison_rm, Jan 04 2017 //We could always just start a global campaign to re- paint all those grid-lines. They're shown very clearly on my OS maps.//
I think carving a meaningful and more permanent trench a few inches wide into the very living rock is the way to go. Rock with a nice square-sided crisp depression in it conveys the kind of gravitas appropriate to the situation. Across oceans, perhaps a nice rocky trench could be floated on pontoons? I think this is the sort of detail engineers are paid for. The natural consequences of this would be that rainwater, litter and the occasional dead seagull would accumulate in the trench. With Greenwich being somewhat elevated compared to say, Villers-sur- mer, there would be a natural tendency, under some conditions, for there to be a flow of detritus into France. If such conditions did not prevail, you could always give it a bit of a going over with a hose and a stick.-- bs0u0155, Jan 07 2017 By George, [bs], damn my eyes if you're not right. I have, this very St. Rudel's day, sent my groundsmen to carve out the gridlines across the estate, at 1° resolution in the first instance. Of course, there's now a couple of inconvenient trenches right through the north-north-east ballroom, but personally I think it adds to the challenge.
I have plans - plans, I say - to increase the resolution down to one second of arc, as soon as the weather improves.
I've also got my man looking into ways of digging trenches in different colours. Should his cognitive labours bear fruit, it is my ardent wish to add contour lines.-- MaxwellBuchanan, Jan 07 2017 random, halfbakery