The missile knows where it is.
this post was submitted on 03 May 2024
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Because the missile knows where it isn't
Ah, the elephant sculpting method of navigation.
I have seen countless posts from this community and I still can't tell what its for
Shitposting related to military matters as far as I can tell.
AFAIK, long shot OSINT.
kinda like how if you talk enough shit, someone will eventually post a restricted document. keeps happening in the Warthunder forums, for example...
On Reddit there are three:
- credibledefence - military nerds analysing military history and present conflicts in a serious way with stringent rules
- lesscredibledefence - fewer rules, casual discussion of mostly current affairs specific to ongoing conflicts
- noncredibledefence - military memes
It's literally just military shitposting.
Who wouldn't love https://en.wikipedia.org/wiki/Sensor_fusion ? It's like you get a magical new sensor that's better than the junk you actually have in your hardware.
Probably just using all the various GPS systems. Unless the Russians are jamming their own system as well.
Given that the Russians took down all of Ukraine's telecoms only to realize that that meant that they couldn't communicate either, and had to therefore use insecure systems does make me think that perhaps they haven't thought it through.
@echodot @IrateAnteater I suspect, despite occasional advances, that on the whole they have thought little of it through. And now their, or rather putines, pride won't let them just say "sorry. We fecked up, just let us back out"
Man, I gotta rewatch Peep Show, I loved it every time that insane character showed up.
Can't remember his name, yep, been too long, time for a rewatch.
How does one jam GPS anyway?
civilian GPS operates at a few fixed frequencies like 1575.42 MHz, 1227.60 MHz, and L5 at 1176.45 MHz (plus 2-3 more; military GPS is a different story). The structure of the GPS data is also fairly well known; all of this is easy to find on the goog.
So you hop on the same frequency start spamming bad GPS data. wrong time stamps, wrong satellite info, etc. with a little effort you can convince a long range missile they're off by 2 miles and should veer left hard.
or you just put a shit ton of noise on the same frequencies and make it so it's forced to use inertial navigation (which isn't very accurate).
Making lots of fake GPS signals, or just pushing lots of power on a GPS frequency.
Isn’t gps NA specific? What good would jamming do?
GPS is a product of the US military; its usefulness to them would be limited if it were North America only, since they mostly wanted it to tell where they were, wherever they happened to be in the world that they had no knowledge of but were actively fuckin' with.
GPS is equally available to civilians in Freedomland as it is to civilians wherever else in the globe. They used to arbitrarily fuck up the signal resolution for the non-military version, until they realized that all they were doing was (a) mildly inconveniencing tech companies who had go through the rite of passage of assigning a single junior programmer to determine how to mostly undo their resolution-fucking-with which wasn't that challenging (b) motivating every other country to develop their own GPS equivalents.
By the time they just let everyone have real GPS, people had cottoned on to the idea that maybe putting your navigation under the whims of the US military wasn't a great idea, and had gone to the pretty significant expense of developing their own. So now there's a bunch of them, and you can pretty much choose whichever one pleases you. But with the exception of NavIC, they're all available all over the world.
wait gps is unscrambled niw? then why is it still so inaccurate?
If you have a modern receiver, like any smartphone from the last 10 years, gps is accurate to a couple of meters.
It’s only a couple of meters for a few of reasons: necessity, speed, and scale.
It’s not necessary for most users to have centimeter precision for gps. Most uses for GPS is for humans to find a place, most humans have eyes, or can at least read braille signs. So if you’re looking for a pizza place and your gps says you’ve arrived, you can look around and see that the pizza place is 3 meters down the road.
Speed, because you can get really accurate locations out of gps, but your receiver would need to refine your location by talking to many satellites many times, which isn’t needed for most users as just knowing if you’re on the right street and the right side of the street is enough. Many communications would mean it takes a long time for the gps device to determine a precise location, which is frustrating for your average user.
And scale, it’s a really big planet, and there’s a finite number of gps satellites. The less satellites in your network, or the less they’ll talk to your receiver, means less accurate data and a less accurate location.
TLDR: most people don’t need sub meter precision from their gps, so it’s simply not provided to most people.
The main limitation now is actually the atmosphere. As the air heats and cools, it expands and contracts. This changes the amount of air the signal is passing through. Since the speed of light in air is slightly slower than vacuum, the effective position accuracy is reduced.
There is a fairly simple correction, you need a static reference. If you have a fixed receiver, then pass its readings to the dynamic one, then you can correct for errors. Combined with inverse kinematics you can get sub centimeter resolution quite reliably.
How inaccurate are we talking? Selective availability used to fuzz location by 30 meters which is insane.
This species is getting spoiled
This page explains the reasons and seems pretty credible (and also gives a date for the descrambling; it was fixed as of May 2000).
In what way is it inaccurate? Google maps can locate you within a couple of meters.
The g stands for global my fellow scholar
Yeah the US likes naming their stuff that way.
It is of course “global” for their world wide operations.
there is 5 different sat nav’s, gps being a US gov Entity…..
GPS belongs to the US government but covers the whole globe