7 ms·

> Well, how about deliberate dilution of precision or intentionally limiting the speed the GPS chip can be used at? Is that a legal requirement or just done on

> Well, how about deliberate dilution of precision or intentionally limiting the speed the GPS chip can be used at? Is that a legal requirement or just done on request? I sort of chuckle whenever I hear of limitations like that being put in place as if someone that can construct an ICBM is going to be constrained by the GPS module.

jimhefferon 6y ago
It was required. But that was gotten rid of by the Clinton administration. See https://www.gps.gov/systems/gps/modernization/sa/ https://www.gps.gov/systems/gps/modernization/sa/ .
- deleted 6y ago
  [deleted]
- loeg 6y ago
  The thing you're thinking of is true, but there are still speed limits on commercial GPS chips to prevent their use in missile guidance systems. TFA seems to be clearly flouting that law, so, good luck to them.
  - hjb 6y ago
    If you dig into their website, they appear to be based in Singapore and Japan. I've no idea if those countries have similar laws.
    - londons_explore 6y ago
      US law applies worldwide when it comes to this sort of stuff... You can bet if you started producing these chips and selling them to Iran, you would either be arrested and child porn found on your laptop, or have an 'accident'.
    - opencl 6y ago
      They indicate plans to sell hardware on Crowdsupply which is based in the US. Presumably this is going to be FPGA-based which brings up all the fun questions of how ITAR applies to software. Would adding a speed restriction in their VHDL that could be trivially bypassed by patching out one line of code satisfy ITAR requirements? AOSP has this sort of code in it (search for ITAR_SPEED_LIMIT): https://android.googlesource.com/platform/frameworks/base/+/master/services/core/java/com/android/server/location/GnssLocationProvider.java https://android.googlesource.com/platform/frameworks/base/+/...
      - gsnedders 6y ago
        > Presumably this is going to be FPGA-based which brings up all the fun questions of how ITAR applies to software. I mean there's plenty of prior art with open-source crypto implementations here.
        tezzer 6y ago
        Crypto is its own category in the ITAR, one whose impact decreased over time as events made the restrictions less relevant. Most crypto is now EAR not ITAR, but treated as a special category. I'm not sure the software classification lessons are going to apply.
- centimeter 6y ago
  Selective Availability was something they did on the satellites (intentionally induce pseudorandom noise into the timing). The regulations on the GPS chips themselves are different.
epanchin 6y ago
The speed limit in the US is 1000mph, else it’s a munition. I believe the US used to make their GPS slightly inaccurate, but this was done on the satellite side.
- willis936 6y ago
  I find a bit of humor in imagining NASA rocket launches and atmospheric test vehicles being viewed, in some contexts, as a munition.
  - Piskvorrr 6y ago
    Well, both the Atlas and Soyuz (currently used by NASA and Roskosmos) were developed primarily for the U.S. and Soviet militaries as ICBM vehicles, the Space Race was something of a PR operation. After all, you don't really need to have an explosive payload: just dropping a heavy enough missile can be devastating.
    - umvi 6y ago
      Are you referring to Kinetic Bombardment?[0] Since kinetic energy increases with the square of velocity, if you can create a payload that can travel at hypersonic speeds (like a tungsten rod) without burning up then the amount of kinetic energy is in the tens of millions of joules. That's enough to destroy any single target, but doesn't have nearly the same destructive power as a nuke, which releases trillions of joules of energy. [0] https://en.wikipedia.org/wiki/Kinetic_bombardment https://en.wikipedia.org/wiki/Kinetic_bombardment
      - numpad0 6y ago
        > That's enough to destroy any single target, but but that’s enough to destroy any single target! Like some bunkers.
        umvi 6y ago
        True, but unless you have hundreds of them, I'm not sure if it's useful for MAD (i.e. replacement for nukes). I suppose if you made the tungsten rods heavy enough and made made them travel fast enough you could get kinetic energy on par with small nukes, but the problem is it's highly directional (i.e. most of the energy is released underground and absorbed by the earth), unlike a nuke which can release all of its energy at once in an airburst 100 feet above a city. It would be useful as a PGM in the arsenal, but probably not enough for MAD in an arms race. I could be wrong, though.
cozzyd 6y ago
We always have to get our altitude restrictions removed for various devices for high-altitude balloon flights.
chc4 6y ago
China also has strict restrictions on GPS data, including requiring purposeful obfuscation of coordinates for their GCJ-02 geodetic datum, for national security purposes. They don't want accurate maps made.
- londons_explore 6y ago
  GCJ-02 used to be a secret way to warp maps to make them less useful for military uses. Now, the GCJ-02 is so well reverse engineered it's practically useless, and just introduces bugs in mapping software when different coordinate systems are used.
  - MrMorden 6y ago
    GCJ-02 might have made things slightly more difficult for India; would it have ever slowed down the US by even a second? I'd be surprised if the country most damaged by that decision in practice wasn't the PRC.
cptskippy 6y ago
It seems silly in today's world where anyone can roll a custom SoC and have it spun out by any number of Fabs over the weekend, but 30 years ago custom chips were pipe-dreams for all but the most advanced tech firms. The $2 microcontroller you use to turn your lamp on has more processing power than a desktop computer from the early 80s. By putting artificial constraints on off-the-shelf GPS technology, it forced bad actors away from off-the-shelf technology and instead forced them to roll their own. This often meant an inferior product with potential compatibility issues and significant development time and costs. The same thing is done with export controls. It seems silly today but in 2000 they were limiting where a Playstation 2 could be exported because at the time a beowulf cluster of PS2s would have been a powerful super computer for a country like Iran. \* Missing words... \\ The next generation of GPS doesn't have Selective Availability, presumably because today there's 3 alternatives to GPS out side of US control.
- wwkeyboard 6y ago
  I thought SA was removed because we discovered ways around it. Specifically differential GPS(tl;dr is that if you have a known point on the ground you can take a measurement there and get the SA offset, this is widely used to compensate for atmospheric error in GPS).
  - mianos 6y ago
    Although WAAS and other similar techniques can be used to improve the accuracy there are many impracticalities of using secondary sources. The reason stated was to encourage civilian uses of the better accuracy. The other federal departments agreed there was more to be gained from civilian use than lost by making the more accurate signal than lost but limiting its use.
    - sunstone 6y ago
      Actually, at the time, once other potential user groups saw how beneficial the technology could be for them (airlines, farmers, on and on) these groups threatened to send up their own GPS systems unless the government agreed to enable full accuracy. The government faced with losing control entirely or meeting the demands of industry chose two work with industry as the US legal writ did not extend to space.
lgats 6y ago
See "COCOM Limits" https://en.wikipedia.org/wiki/Coordinating_Committee_for_Multilateral_Export_Controls#Legacy https://en.wikipedia.org/wiki/Coordinating_Committee_for_Mul...

jimhefferon 6y ago

It was required. But that was gotten rid of by the Clinton administration. See https://www.gps.gov/systems/gps/modernization/sa/ https://www.gps.gov/systems/gps/modernization/sa/ .

deleted 6y ago
[deleted]
loeg 6y ago
The thing you're thinking of is true, but there are still speed limits on commercial GPS chips to prevent their use in missile guidance systems. TFA seems to be clearly flouting that law, so, good luck to them.
- hjb 6y ago
  If you dig into their website, they appear to be based in Singapore and Japan. I've no idea if those countries have similar laws.
  - londons_explore 6y ago
    US law applies worldwide when it comes to this sort of stuff... You can bet if you started producing these chips and selling them to Iran, you would either be arrested and child porn found on your laptop, or have an 'accident'.
  - opencl 6y ago
    They indicate plans to sell hardware on Crowdsupply which is based in the US. Presumably this is going to be FPGA-based which brings up all the fun questions of how ITAR applies to software. Would adding a speed restriction in their VHDL that could be trivially bypassed by patching out one line of code satisfy ITAR requirements? AOSP has this sort of code in it (search for ITAR_SPEED_LIMIT): https://android.googlesource.com/platform/frameworks/base/+/master/services/core/java/com/android/server/location/GnssLocationProvider.java https://android.googlesource.com/platform/frameworks/base/+/...
    - gsnedders 6y ago
      > Presumably this is going to be FPGA-based which brings up all the fun questions of how ITAR applies to software. I mean there's plenty of prior art with open-source crypto implementations here.
      - tezzer 6y ago
        Crypto is its own category in the ITAR, one whose impact decreased over time as events made the restrictions less relevant. Most crypto is now EAR not ITAR, but treated as a special category. I'm not sure the software classification lessons are going to apply.
centimeter 6y ago
Selective Availability was something they did on the satellites (intentionally induce pseudorandom noise into the timing). The regulations on the GPS chips themselves are different.

epanchin 6y ago

The speed limit in the US is 1000mph, else it’s a munition. I believe the US used to make their GPS slightly inaccurate, but this was done on the satellite side.

willis936 6y ago
I find a bit of humor in imagining NASA rocket launches and atmospheric test vehicles being viewed, in some contexts, as a munition.
- Piskvorrr 6y ago
  Well, both the Atlas and Soyuz (currently used by NASA and Roskosmos) were developed primarily for the U.S. and Soviet militaries as ICBM vehicles, the Space Race was something of a PR operation. After all, you don't really need to have an explosive payload: just dropping a heavy enough missile can be devastating.
  - umvi 6y ago
    Are you referring to Kinetic Bombardment?[0] Since kinetic energy increases with the square of velocity, if you can create a payload that can travel at hypersonic speeds (like a tungsten rod) without burning up then the amount of kinetic energy is in the tens of millions of joules. That's enough to destroy any single target, but doesn't have nearly the same destructive power as a nuke, which releases trillions of joules of energy. [0] https://en.wikipedia.org/wiki/Kinetic_bombardment https://en.wikipedia.org/wiki/Kinetic_bombardment
    - numpad0 6y ago
      > That's enough to destroy any single target, but but that’s enough to destroy any single target! Like some bunkers.
      - umvi 6y ago
        True, but unless you have hundreds of them, I'm not sure if it's useful for MAD (i.e. replacement for nukes). I suppose if you made the tungsten rods heavy enough and made made them travel fast enough you could get kinetic energy on par with small nukes, but the problem is it's highly directional (i.e. most of the energy is released underground and absorbed by the earth), unlike a nuke which can release all of its energy at once in an airburst 100 feet above a city. It would be useful as a PGM in the arsenal, but probably not enough for MAD in an arms race. I could be wrong, though.

cozzyd 6y ago

We always have to get our altitude restrictions removed for various devices for high-altitude balloon flights.

chc4 6y ago

China also has strict restrictions on GPS data, including requiring purposeful obfuscation of coordinates for their GCJ-02 geodetic datum, for national security purposes. They don't want accurate maps made.

londons_explore 6y ago
GCJ-02 used to be a secret way to warp maps to make them less useful for military uses. Now, the GCJ-02 is so well reverse engineered it's practically useless, and just introduces bugs in mapping software when different coordinate systems are used.
- MrMorden 6y ago
  GCJ-02 might have made things slightly more difficult for India; would it have ever slowed down the US by even a second? I'd be surprised if the country most damaged by that decision in practice wasn't the PRC.

cptskippy 6y ago

It seems silly in today's world where anyone can roll a custom SoC and have it spun out by any number of Fabs over the weekend, but 30 years ago custom chips were pipe-dreams for all but the most advanced tech firms. The $2 microcontroller you use to turn your lamp on has more processing power than a desktop computer from the early 80s. By putting artificial constraints on off-the-shelf GPS technology, it forced bad actors away from off-the-shelf technology and instead forced them to roll their own. This often meant an inferior product with potential compatibility issues and significant development time and costs. The same thing is done with export controls. It seems silly today but in 2000 they were limiting where a Playstation 2 could be exported because at the time a beowulf cluster of PS2s would have been a powerful super computer for a country like Iran. \* Missing words... \\ The next generation of GPS doesn't have Selective Availability, presumably because today there's 3 alternatives to GPS out side of US control.

wwkeyboard 6y ago
I thought SA was removed because we discovered ways around it. Specifically differential GPS(tl;dr is that if you have a known point on the ground you can take a measurement there and get the SA offset, this is widely used to compensate for atmospheric error in GPS).
- mianos 6y ago
  Although WAAS and other similar techniques can be used to improve the accuracy there are many impracticalities of using secondary sources. The reason stated was to encourage civilian uses of the better accuracy. The other federal departments agreed there was more to be gained from civilian use than lost by making the more accurate signal than lost but limiting its use.
  - sunstone 6y ago
    Actually, at the time, once other potential user groups saw how beneficial the technology could be for them (airlines, farmers, on and on) these groups threatened to send up their own GPS systems unless the government agreed to enable full accuracy. The government faced with losing control entirely or meeting the demands of industry chose two work with industry as the US legal writ did not extend to space.

lgats 6y ago

See "COCOM Limits" https://en.wikipedia.org/wiki/Coordinating_Committee_for_Multilateral_Export_Controls#Legacy https://en.wikipedia.org/wiki/Coordinating_Committee_for_Mul...