Earlier quoted context omitted.
> sustaining human life Not really. Drone ships are very much a thing these days.
How can a drone ship hold its designated position while it's blocking gps?
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Cheap GPS jammers are filling the world with navigation dead zones
161–170 of 243 posts
Re: Cheap GPS jammers are filling the world with navigation dead zones
#162Whats really sad for aviation is there was already an extensive network of ground based navaids. As GPS has proliferated, they've slowly been decommissioned as they age out to save on cost. I'm specifically referring to VORs which provide azimuth and range to station. GPS is fantastic and as a primary source everyone loves the benefits it brings. However, in a century of aviation, everyone has kinda sorted out that y…
maybe we need to update those giant concrete arrows on the ground... https://en.wikipedia.org/wiki/Transcontinental_Airway_System and have giant concrete QR codes
You're not far off with the QR codes. Some military hardware actually match camera input to known maps to navigate. Mostly unmanned, one-way hardware.
Re: Cheap GPS jammers are filling the world with navigation dead zones
#163Earlier quoted context omitted.
Oh wow but a GPS jammer is okay so someone could get lost and possibly killed, or even crash a plane?
i’m delighted to report that it’s actually possible for people to talk about a second, related topic in a comment section without invalidating the problems of the main post being commented on
Many people do not understand this concept!
Re: Cheap GPS jammers are filling the world with navigation dead zones
#164Jamming and spoofing have come out of the shadows and into the mainstream. Naive receivers will soon be outclassed by smart receivers.
Re: Cheap GPS jammers are filling the world with navigation dead zones
#165Whats really sad for aviation is there was already an extensive network of ground based navaids. As GPS has proliferated, they've slowly been decommissioned as they age out to save on cost. I'm specifically referring to VORs which provide azimuth and range to station. GPS is fantastic and as a primary source everyone loves the benefits it brings. However, in a century of aviation, everyone has kinda sorted out that y…
Sorry but this sounds like nostalgia. loran-c was prone to error.
Yes, we can stop that with modern tech, but the problem with loran-c is you had location ambiguities. Decca was worse, unless you had a good initial fix, you were all sorts of fucked. There are of course modern alternatives, but they are not block proof, or turned on.
There is a very good reason why GPS was opened up, because the alternatives were not anywhere near as good.
Now, what are the alternatives? well hyperbolic navigation is still a thing, and with modern electronics you can get a pretty good fix without any of the nasty ambiguaty that loran-c had. If you are flying over land, then visual odometry is now at a point where you can locate pretty accurately autonomously (assuming cloud cover is your firend)
Small low power ceasium clocks are $4k now, and only really need a few hundred millitwatts to run, which opens up a whole load of other ways to navigate.
then there are IMUs, they are dirt cheap and way more accurate than 20 years ago. A calibrated array should be able to sustain reasonable accuracy after 30 minutes now
Re: Cheap GPS jammers are filling the world with navigation dead zones
#166Earlier quoted context omitted.
Starlink lacks the high precision atomic clocks on board of the satellites, that is also why Starlink needs a GPS fix to bootstrap itself.
Maybe the starlink clocks could continuously calibrate from gps? Clock drift is usually a slow thing (like thermals). Their inter-satellite data links have all sorts of relative clocking info.
The orbit accuracy of starlinks are (to me) and unknown. I would suggest that as they are on a lower orbit, they decay much faster.
However, because of the way they communicate node to node, they do need to know where their nearest neighbour is to a very high degree. So relative position is probably easy to obtain.
But if you're gonna do that, you're better off with 4g/5g masts. there are loads of them and they don't generally change position that much. They are clow enough together to do odometry.
Unless youre over the sea.
Re: Cheap GPS jammers are filling the world with navigation dead zones
#167Earlier quoted context omitted.
Not really. It uses 2MHz band, with the wavelength of around 160m. This means that it's easy to receive via a ferrite bar antenna but hard to transmit. You need an antenna of at least around 40m size for that to be efficient.
Even a 160m guy-wire tower is cheap. 40m.. my friend installed 32m one just to have better internets, not exactly out of pocket cash, but nothing compared to say swapping a car.
yes, but trying to pump 25kw through that without it being obvious is a lot harder.
Re: Cheap GPS jammers are filling the world with navigation dead zones
#168Earlier quoted context omitted.
That's near orders of magnitude more than reality. The only number that matters is the number of satellites that are in communication line of site. A satellite on the other side of the world doesn't help you.
I wonder how many are in view? gps is 31 total satellites 12,000 miles up starlink is 10,000 satellites at ~ 300 miles. (and what orbit?) EDIT: I found this: -- starlink: "In any given place there are 3-4 Starlink satellites visible at a time" https://news.ycombinator.com/item?id=42445512 :) in december 2024, there were 4,000 starlink satellites in orbit so starlink is ~ 8 at all times? -- GPS: This 24-slot arrangeme…
You also need to know where the satellites are meant to be at any one time. That means a stable orbit. Starlink isn't really designed for that.
It then also needs to be signed/secure so that its not spoofed.
Then your signal that your measuring time from needs to be transmitted often enough and robust enough. Plus your time source on the transmitter needs to be accurate enough.
It might be possible with starlink, but you'd also have to trust musk....
Re: Cheap GPS jammers are filling the world with navigation dead zones
#169I wish there were cheap Bluetooth jammers to prevent speakers from playing when hiking
These takes are unreasonable IMHO. When you pass someone on the trail, even with a BT speaker blasting you hear the music for what.. maybe 15-20 seconds? Is that really ruining your day? Sometimes when I walk or bike with my wife we bring a BT speaker and I can BARELY hear it and I'm walking side-by-side with her getting no more than 15-20 feet away. Let. People. Enjoy. Things.
Edit: Moderated some of my language.
Re: Cheap GPS jammers are filling the world with navigation dead zones
#170Earlier quoted context omitted.
Where do you hike where it’s a problem? I mean if I meet perhaps 10 people max over 2 hours. If all of them were blasting music it still wouldn’t worry me at all.
We encountered this on the Inca trail in Peru. All it takes is one rude person.
If passing one person the trail playing audible music ruins your entire experience I'd check on your mental health. Seriously. I too can get mad at ridiculous things (line cutters, rude drivers, loud movie goers) and have to make a conscious effort to stop, take a deep breath and ask myself why I'm letting this innocuous thing effect my day.