5 ms·

NOAA doesn't list any meaningful geomagnetic storms right now: https://www.swpc.noaa.gov/communities/space-weather-enthusiasts https://www.swpc.noaa.gov/commun

by tjohns 4y ago

NOAA doesn't list any meaningful geomagnetic storms right now: https://www.swpc.noaa.gov/communities/space-weather-enthusiasts https://www.swpc.noaa.gov/communities/space-weather-enthusia... But that aside, I'd really hope that these cars are using professional WAAS-capable GPS receivers. Short of a major X-class flare which knocks out the WAAS geostationary satellites, the entire point of the system is to correct for these kinds of disturbances to the GPS signals.

Natsu 4y ago
Why does this make me wonder if something is going on with GPS due to the war in Ukraine?
- mh- 4y ago
  EDIT: the following is incorrect per a reply below. Will leave the original comment below. --- That was going to be my hypothesis. GPS resolution can be reduced in a conflict area. I'll defer to someone with actual knowledge to add more info. :)
  - TaylorAlexander 4y ago
    I believe the government promised not to ever reduce GPS resolution some 15 years ago, and new satellites supposedly do not even have the ability to do so.
    - mh- 4y ago
      TIL, apologies for the misinformation! Will correct my comment if it's still in the edit window
    - HHC-Hunter 4y ago
      Oh my sweet summer child.
      - RajT88 4y ago
        I am old enough to recall when they did so post-9/11. The US government would never give up such a capability, that would be out of character for them. But they would sure as hell pretend like they did, which is very much in character.
        booi 4y ago
        I think they would. There's at least 3 fully operational GPS alternatives, there's no reason to have this capability anymore. Some receivers will combine all of these systems.
        lolc 4y ago
        All these systems are rigged to jam and spoof at the push of a button I expect.
        lozenge 4y ago
        They are owned by: China, Russia, India, Europe and Japan.
      - TaylorAlexander 4y ago
        There was a specific technical capability that they used to reserve the right to use, and I believe they no longer need to use that capability. Obviously this would only be the case if they have some alternative capability. But I forget the name of the feature so I am having trouble looking up sources. I obviously do not take the government at its word, but I can believe that a technical capability developed in the 1980's might no longer be the most useful counter measure. Especially since there are now 5 GNSS constellation systems, with GPS only being one of them, and low cost off the shelf receivers can read all of them.
    - StanislavPetrov 4y ago
      Years ago a government promise and .25 cents could get you a phone call. Today you won't even get the phone call.
  - zaarn 4y ago
    Reduction of GPS Resolution is limited to specific areas, it can be targeted. If they are doing it (probably are in Ukraine) then it only affects some areas. You can also bypass that restriction if you have the right military keys (read: Ukraine).
    - mh- 4y ago
      Yeah, that is what my (perhaps outdated?) understanding was.
      - zaarn 4y ago
        What is said is the current capabilities. All other GNS systems have the same capabilities (though European GNS Galileo has some more modern features and the Soviet one is a bit of a shitshow)
        dasv 4y ago
        This submission is worrying me a bit, my company's product depends on GPS+GLONASS with RTK assistance at high latitudes for high accuracy high frequency positioning. The NTRIP RTK services we use just provides assistance for GPS+GLONASS, no Galileo or BeiDou. GLONASS is crucial because the satellite orbits are more visible at high latitudes providing better reception. Still, RTK should help cope with this problem but I might have to check last week's collections.
    - fest 4y ago
      And your systems actually support decryption and entering the said keys. You might be surprised what proportion of the hardware that operates in Ukraine (from both sides) is using civillian grade GPS receivers (i.e. almost anything with a price tag of less than 1M USD).
- throwaway742 4y ago
  From the linked reddit thread: >Does this happen when you're not using Glonass? I wonder if Russia has been 'tweeking' it. >I've switched to Galileo and the problem is FIXED.
KennyBlanken 4y ago
WAAS has been available on consumer GPS devices since the mid 2000's and is not "professional" nor does it address reception/interference issus; WAAS provides semi-real-time position refinement data based off drift observed by ground stations within a certain range to compensate for things like atmospheric disruption of the signal. WAAS is built-in to the vast majority of receivers these days. Multi-band GNSS is what helps address issues around reception like multipath and interference. Receivers used to be pretty expensive, and the number of L5 satellites wasn't that high until the last few years, but now can be found in even a number of consumer electronic devices, and the number of L5 satellites keeps going up (and as more satellites have L5 signals, things will get better.) Several Garmin sport devices have it now, for example. A quick search shows Maxim sells a multi-band GNSS chipset for $10. There is really no excuse for any autonomous vehicle company to not be at least evaluating multi-band GPS receivers, if only to give more reliable position data in urban environs. I'd be surprised if at least some aren't using RTK receivers, but this requires a base station within a certain range of the cars, or commercial service (such as that offered to farmers by John Deere.) RTK just isn't that expensive compared to even a single LIDAR unit. Edit: they can tolerate at least some degree of GPS degradation and use dead reckoning / lidar data in some cases, according to this person: https://news.ycombinator.com/item?id=31940167 https://news.ycombinator.com/item?id=31940167
lsllc 4y ago
I just read about a sunspot that recently doubled in size [0] and maybe launched a CME in our direction -- we don't really know due to a power outage at Stanford University that took the SDO offline [1], anyway food for thought, maybe it's coincidence. [0] https://scitechdaily.com/auroras-incoming-giant-sunspot-has-doubled-in-size-and-is-pointed-right-at-earth/ https://scitechdaily.com/auroras-incoming-giant-sunspot-has-... [1] https://interestingengineering.com/a-huge-solar-eruption https://interestingengineering.com/a-huge-solar-eruption
jrockway 4y ago
I'm not really seeing anything weird with GNSS. I have a continuously-operating receiver that writes its location into a database every second; I did a query over the last 30 days and there is no abnormal deviation in position. (My receiver is in a terrible location that can only see a tiny sliver of the sky, and is single-band, so I expect about a +/- 50cm deviation without RTK correction and that's what I'm seeing.) I actually haven't looked at this data for quite a while. I didn't consider the start of the Ukraine war a good reason to start looking at my data, and I delete it after 30 days to save $$$ on block storage. Dumb. (I added some proper downsampling today so I can keep it forever at reasonable cost.) Trusting my own data is always suspicious, so I clicked around randomly on the NYS Spatial Reference Network website (https://cors.dot.ny.gov/ https://cors.dot.ny.gov/; the title of the page is "Shop", but accounts and RTK access are free). They operate a bunch of Continuously Operating Reference Stations and publish statistics about the accuracy. I do see a lot of reported GLONASS cycle slips today. I have no idea if that is normal or not; this is the first time I've ever dug that deeply into station stats. But overall, the position accuracy at the stations I spot-checked are within .5cm, which is normal. (Most use 4 constellations; GPS, GLONASS, Beidou, Galileo; on 2 bands. So even if GLONASS is broken today, one constellation is enough for good accuracy.) If the government has degraded GPS accuracy today as many commenters think have happened, many people would have noticed. The reference stations have known positions; if GPS starts saying they're somewhere else, that's impossible and would be flagged. GPS being significantly degraded would probably be front page news; not just noticed by a few exercise tracking enthusiasts on Reddit. Or maybe it's all a big conspiracy and the US and Russia banded together to hack my database and the NYS spatial reference network. It could happen, I guess, but my non expert opinion is that GPS is fine right now.
- mellavora 4y ago
  > my non expert opinion Yes, clearly given the detail in your post, you are "not an expert". Thanks for being on HN and making this site great.
  - dasv 4y ago
    There is a lot of depth to GNSS! I could do what jrockway did on the grandparent comment and I would not define myself either as anything near an expert on the field.

by tjohns 4y ago

Natsu 4y ago

Why does this make me wonder if something is going on with GPS due to the war in Ukraine?

mh- 4y ago
EDIT: the following is incorrect per a reply below. Will leave the original comment below. --- That was going to be my hypothesis. GPS resolution can be reduced in a conflict area. I'll defer to someone with actual knowledge to add more info. :)
- TaylorAlexander 4y ago
  I believe the government promised not to ever reduce GPS resolution some 15 years ago, and new satellites supposedly do not even have the ability to do so.
  - mh- 4y ago
    TIL, apologies for the misinformation! Will correct my comment if it's still in the edit window
  - HHC-Hunter 4y ago
    Oh my sweet summer child.
    - RajT88 4y ago
      I am old enough to recall when they did so post-9/11. The US government would never give up such a capability, that would be out of character for them. But they would sure as hell pretend like they did, which is very much in character.
      - booi 4y ago
        I think they would. There's at least 3 fully operational GPS alternatives, there's no reason to have this capability anymore. Some receivers will combine all of these systems.
        lolc 4y ago
        All these systems are rigged to jam and spoof at the push of a button I expect.
        lozenge 4y ago
        They are owned by: China, Russia, India, Europe and Japan.
    - TaylorAlexander 4y ago
      There was a specific technical capability that they used to reserve the right to use, and I believe they no longer need to use that capability. Obviously this would only be the case if they have some alternative capability. But I forget the name of the feature so I am having trouble looking up sources. I obviously do not take the government at its word, but I can believe that a technical capability developed in the 1980's might no longer be the most useful counter measure. Especially since there are now 5 GNSS constellation systems, with GPS only being one of them, and low cost off the shelf receivers can read all of them.
  - StanislavPetrov 4y ago
    Years ago a government promise and .25 cents could get you a phone call. Today you won't even get the phone call.
- zaarn 4y ago
  Reduction of GPS Resolution is limited to specific areas, it can be targeted. If they are doing it (probably are in Ukraine) then it only affects some areas. You can also bypass that restriction if you have the right military keys (read: Ukraine).
  - mh- 4y ago
    Yeah, that is what my (perhaps outdated?) understanding was.
    - zaarn 4y ago
      What is said is the current capabilities. All other GNS systems have the same capabilities (though European GNS Galileo has some more modern features and the Soviet one is a bit of a shitshow)
      - dasv 4y ago
        This submission is worrying me a bit, my company's product depends on GPS+GLONASS with RTK assistance at high latitudes for high accuracy high frequency positioning. The NTRIP RTK services we use just provides assistance for GPS+GLONASS, no Galileo or BeiDou. GLONASS is crucial because the satellite orbits are more visible at high latitudes providing better reception. Still, RTK should help cope with this problem but I might have to check last week's collections.
  - fest 4y ago
    And your systems actually support decryption and entering the said keys. You might be surprised what proportion of the hardware that operates in Ukraine (from both sides) is using civillian grade GPS receivers (i.e. almost anything with a price tag of less than 1M USD).
throwaway742 4y ago
From the linked reddit thread: >Does this happen when you're not using Glonass? I wonder if Russia has been 'tweeking' it. >I've switched to Galileo and the problem is FIXED.

KennyBlanken 4y ago

WAAS has been available on consumer GPS devices since the mid 2000's and is not "professional" nor does it address reception/interference issus; WAAS provides semi-real-time position refinement data based off drift observed by ground stations within a certain range to compensate for things like atmospheric disruption of the signal. WAAS is built-in to the vast majority of receivers these days. Multi-band GNSS is what helps address issues around reception like multipath and interference. Receivers used to be pretty expensive, and the number of L5 satellites wasn't that high until the last few years, but now can be found in even a number of consumer electronic devices, and the number of L5 satellites keeps going up (and as more satellites have L5 signals, things will get better.) Several Garmin sport devices have it now, for example. A quick search shows Maxim sells a multi-band GNSS chipset for $10. There is really no excuse for any autonomous vehicle company to not be at least evaluating multi-band GPS receivers, if only to give more reliable position data in urban environs. I'd be surprised if at least some aren't using RTK receivers, but this requires a base station within a certain range of the cars, or commercial service (such as that offered to farmers by John Deere.) RTK just isn't that expensive compared to even a single LIDAR unit. Edit: they can tolerate at least some degree of GPS degradation and use dead reckoning / lidar data in some cases, according to this person: https://news.ycombinator.com/item?id=31940167 https://news.ycombinator.com/item?id=31940167

lsllc 4y ago

I just read about a sunspot that recently doubled in size [0] and maybe launched a CME in our direction -- we don't really know due to a power outage at Stanford University that took the SDO offline [1], anyway food for thought, maybe it's coincidence. [0] https://scitechdaily.com/auroras-incoming-giant-sunspot-has-doubled-in-size-and-is-pointed-right-at-earth/ https://scitechdaily.com/auroras-incoming-giant-sunspot-has-... [1] https://interestingengineering.com/a-huge-solar-eruption https://interestingengineering.com/a-huge-solar-eruption

jrockway 4y ago

I'm not really seeing anything weird with GNSS. I have a continuously-operating receiver that writes its location into a database every second; I did a query over the last 30 days and there is no abnormal deviation in position. (My receiver is in a terrible location that can only see a tiny sliver of the sky, and is single-band, so I expect about a +/- 50cm deviation without RTK correction and that's what I'm seeing.) I actually haven't looked at this data for quite a while. I didn't consider the start of the Ukraine war a good reason to start looking at my data, and I delete it after 30 days to save $$$ on block storage. Dumb. (I added some proper downsampling today so I can keep it forever at reasonable cost.) Trusting my own data is always suspicious, so I clicked around randomly on the NYS Spatial Reference Network website (https://cors.dot.ny.gov/ https://cors.dot.ny.gov/; the title of the page is "Shop", but accounts and RTK access are free). They operate a bunch of Continuously Operating Reference Stations and publish statistics about the accuracy. I do see a lot of reported GLONASS cycle slips today. I have no idea if that is normal or not; this is the first time I've ever dug that deeply into station stats. But overall, the position accuracy at the stations I spot-checked are within .5cm, which is normal. (Most use 4 constellations; GPS, GLONASS, Beidou, Galileo; on 2 bands. So even if GLONASS is broken today, one constellation is enough for good accuracy.) If the government has degraded GPS accuracy today as many commenters think have happened, many people would have noticed. The reference stations have known positions; if GPS starts saying they're somewhere else, that's impossible and would be flagged. GPS being significantly degraded would probably be front page news; not just noticed by a few exercise tracking enthusiasts on Reddit. Or maybe it's all a big conspiracy and the US and Russia banded together to hack my database and the NYS spatial reference network. It could happen, I guess, but my non expert opinion is that GPS is fine right now.

mellavora 4y ago
> my non expert opinion Yes, clearly given the detail in your post, you are "not an expert". Thanks for being on HN and making this site great.
- dasv 4y ago
  There is a lot of depth to GNSS! I could do what jrockway did on the grandparent comment and I would not define myself either as anything near an expert on the field.