4 ms·

> GPS is just not 100% reliable (ask me how I know) How to you know?

tawm 4y ago
As OP hasn't replied yet, I'll take the liberty. The biggest issue is interference (jamming) by malicious actors. This is especially common in the eastern Mediterranean [1]. Earlier this year there have also been reports of interference on Finland's border with Russia [2]. Of course one could imagine other scenarios where GPS might become inaccurate or unavailable on a larger scale, such as an attack on the satellites themselves. [1] https://safety4sea.com/us-marad-gps-interference-incidents-reported-in-the-eastern-mediterranean-sea/ https://safety4sea.com/us-marad-gps-interference-incidents-r... [2] https://www.traficom.fi/en/news/unusual-amount-reports-about-gps-interference-near-eastern-border-finland https://www.traficom.fi/en/news/unusual-amount-reports-about... (my guess is that _moof is a navigator with experience in the eastern med sea)
- deepstack 4y ago
  in android, the GPS config file (some xml) file will do the trick of making the at least the GPS/Location system on the phone unreliable. Apparently each country has their own config file. Found this out when a friend used the Android bought in China in US. So no GPS is NOT reliable for critical situations, it is more a consumer connivence ATM.
  - Hitton 4y ago
    Nope. It's maps in China that are unreliable. On purpose. https://www.serviceobjects.com/blog/why-gps-coordinates-look-wrong-on-maps-of-china/ https://www.serviceobjects.com/blog/why-gps-coordinates-look...
- mortenlarsen 4y ago
  It is not that I do not know that GPS is unreliable. But I wanted to read about what OP had experienced specifically.
- flyinghamster 4y ago
  > The biggest issue is interference (jamming) by malicious actors. And not necessarily malicious. Before I ditched Strava (insert separate rant about tech "ecosystems"), one of my bike rides took me near a nuclear power plant. The resulting GPS track had a sudden hundreds-of-feet "climb" near the power plant that didn't exist in the real world, as if I had literally climbed a wall on my bike.
wbl 4y ago
I wanted to dim the chart plotter. I turned it off: was the same button, required a push of a different length. If I wasn't aware of where my bow was pointed and what I was trying to do at the time, it would have been a big problem, particularly in traffic. But because I knew where I was and what I was doing I was able to continue to sail and turn everything back on.

tawm 4y ago

As OP hasn't replied yet, I'll take the liberty. The biggest issue is interference (jamming) by malicious actors. This is especially common in the eastern Mediterranean [1]. Earlier this year there have also been reports of interference on Finland's border with Russia [2]. Of course one could imagine other scenarios where GPS might become inaccurate or unavailable on a larger scale, such as an attack on the satellites themselves. [1] https://safety4sea.com/us-marad-gps-interference-incidents-reported-in-the-eastern-mediterranean-sea/ https://safety4sea.com/us-marad-gps-interference-incidents-r... [2] https://www.traficom.fi/en/news/unusual-amount-reports-about-gps-interference-near-eastern-border-finland https://www.traficom.fi/en/news/unusual-amount-reports-about... (my guess is that _moof is a navigator with experience in the eastern med sea)

deepstack 4y ago
in android, the GPS config file (some xml) file will do the trick of making the at least the GPS/Location system on the phone unreliable. Apparently each country has their own config file. Found this out when a friend used the Android bought in China in US. So no GPS is NOT reliable for critical situations, it is more a consumer connivence ATM.
- Hitton 4y ago
  Nope. It's maps in China that are unreliable. On purpose. https://www.serviceobjects.com/blog/why-gps-coordinates-look-wrong-on-maps-of-china/ https://www.serviceobjects.com/blog/why-gps-coordinates-look...
mortenlarsen 4y ago
It is not that I do not know that GPS is unreliable. But I wanted to read about what OP had experienced specifically.
flyinghamster 4y ago
> The biggest issue is interference (jamming) by malicious actors. And not necessarily malicious. Before I ditched Strava (insert separate rant about tech "ecosystems"), one of my bike rides took me near a nuclear power plant. The resulting GPS track had a sudden hundreds-of-feet "climb" near the power plant that didn't exist in the real world, as if I had literally climbed a wall on my bike.

wbl 4y ago

I wanted to dim the chart plotter. I turned it off: was the same button, required a push of a different length. If I wasn't aware of where my bow was pointed and what I was trying to do at the time, it would have been a big problem, particularly in traffic. But because I knew where I was and what I was doing I was able to continue to sail and turn everything back on.