4 ms·

Occurred to me that in a war or over the water this wouldn’t be useful. But I think it will be a useful technology (that to be fair likely already exists), in a

Occurred to me that in a war or over the water this wouldn’t be useful. But I think it will be a useful technology (that to be fair likely already exists), in addition to highly accurate dead reckoning systems, when GPS is knocked out or unreliable, as secondary fall back navigation.

jnwatson 3y ago
For only $300 plus shipping from Ali Express you get a high accuracy inertial navigation system. Only weighs 10 grams. The future is scary. It is now straightforward and inexpensive for lots of folks to construct jam-resistant Shahed-style drones. https://www.aliexpress.com/item/1005006499367697.html https://www.aliexpress.com/item/1005006499367697.html
- ufocia 3y ago
  Sounds expensive.
- deno 3y ago
  Sold by "Peace Dove Grocery Store."
- dilyevsky 3y ago
  “High accuracy”
- Animats 3y ago
  And for a little less, you can buy the original, from Analog Devices.[1] Those things are getting really good. The drift specs keep getting better - a few degrees per hour now. The last time I used that kind of thing it was many degrees per minute. Linear motion is still a problem, because, if all you have is accelerometers, position and velocity error accumulates rapidly. A drone with a downward looking camera can get a vector from simple optical flow and use that to correct the IMU. Won't work very well over water, though. [1] https://www.analog.com/en/products/ADIS16460.html https://www.analog.com/en/products/ADIS16460.html
  - sigmoid10 3y ago
    >Linear motion is still a problem, because, if all you have is accelerometers, position and velocity error accumulates rapidly. An INS will usually need some kind of sensor fusion to become accurate anyways. Like how certain intercontinental ballistic missiles use stars (sometimes only a single one) as reference. But all these things are based on the assumption of clear sight and even this google maps image based navigation will fail if the weather is bad.
    - Animats 3y ago
      10^-5 degrees/hour drift was achieved in the 1970s, for ICBMs, at very high cost.
      - pjc50 3y ago
        The laser ring gyro? It'll be fun when those start showing up on Aliexpress.
Modified3019 3y ago
For oceans, they could use juvenile loggerhead turtles: https://www.reed.edu/biology/courses/BIO342/2011_syllabus/2011_websites/HSMVSS8/mechanism.html https://www.reed.edu/biology/courses/BIO342/2011_syllabus/20...
krisoft 3y ago
> in a war … wouldn’t be useful Why do you say that? Navigational techniques like this (developed and validated over longer timeframes of course) are precisely for war where you want to cause mayhem for your enemies who want to prevent you from doing that by jamming GPS. This is not just an idea but we have already fielded systems. > over the water this wouldn’t be useful What is typically done with cruise missiles launched from sea that there is a wide sweep of the coast mapped where it is predicted to make landfall. How wide this zone has to be depends on the performance of the innertial guidance and the quality of the fix it is starting out with.
- hef19898 3y ago
  Well, landmarks have a tendency to change quickly in a war zone. Making whatever map material you have useless, or close to useless. All the navigational methods predating GPS still work perfectly fine so.
  - littlestymaar 3y ago
    You can get new satellite imagery ever day… (be it military ones if you're a major power, or just commercial one like your average OSINter)
    - hef19898 3y ago
      Sure. And then you have to upload those new, and vetted, imagines to all your drones. Other nav data is much more stable. Mind you, military hardware is not your smartphone, OTA updates are usually not a thong for various reasons. The approach for sure is interesting so.
      - magicalhippo 3y ago
        Well if you combine it with dead reckoning, I guess even a war torn field could be referenced against a pre-war image? I mean, a prominent tree along a stone wall might be sufficient to be fairly sure, if you at least got some idea of the area you're in via dead reckoning.
mytailorisrich 3y ago
Being able to nagivate using only a map stored locally sounds extremely useful in a war.
dwighttk 3y ago
Don’t we have basically this but it looks at stars?

jnwatson 3y ago

For only $300 plus shipping from Ali Express you get a high accuracy inertial navigation system. Only weighs 10 grams. The future is scary. It is now straightforward and inexpensive for lots of folks to construct jam-resistant Shahed-style drones. https://www.aliexpress.com/item/1005006499367697.html https://www.aliexpress.com/item/1005006499367697.html

ufocia 3y ago
Sounds expensive.
deno 3y ago
Sold by "Peace Dove Grocery Store."
dilyevsky 3y ago
“High accuracy”
Animats 3y ago
And for a little less, you can buy the original, from Analog Devices.[1] Those things are getting really good. The drift specs keep getting better - a few degrees per hour now. The last time I used that kind of thing it was many degrees per minute. Linear motion is still a problem, because, if all you have is accelerometers, position and velocity error accumulates rapidly. A drone with a downward looking camera can get a vector from simple optical flow and use that to correct the IMU. Won't work very well over water, though. [1] https://www.analog.com/en/products/ADIS16460.html https://www.analog.com/en/products/ADIS16460.html
- sigmoid10 3y ago
  >Linear motion is still a problem, because, if all you have is accelerometers, position and velocity error accumulates rapidly. An INS will usually need some kind of sensor fusion to become accurate anyways. Like how certain intercontinental ballistic missiles use stars (sometimes only a single one) as reference. But all these things are based on the assumption of clear sight and even this google maps image based navigation will fail if the weather is bad.
  - Animats 3y ago
    10^-5 degrees/hour drift was achieved in the 1970s, for ICBMs, at very high cost.
    - pjc50 3y ago
      The laser ring gyro? It'll be fun when those start showing up on Aliexpress.

Modified3019 3y ago

For oceans, they could use juvenile loggerhead turtles: https://www.reed.edu/biology/courses/BIO342/2011_syllabus/2011_websites/HSMVSS8/mechanism.html https://www.reed.edu/biology/courses/BIO342/2011_syllabus/20...

krisoft 3y ago

> in a war … wouldn’t be useful Why do you say that? Navigational techniques like this (developed and validated over longer timeframes of course) are precisely for war where you want to cause mayhem for your enemies who want to prevent you from doing that by jamming GPS. This is not just an idea but we have already fielded systems. > over the water this wouldn’t be useful What is typically done with cruise missiles launched from sea that there is a wide sweep of the coast mapped where it is predicted to make landfall. How wide this zone has to be depends on the performance of the innertial guidance and the quality of the fix it is starting out with.

hef19898 3y ago
Well, landmarks have a tendency to change quickly in a war zone. Making whatever map material you have useless, or close to useless. All the navigational methods predating GPS still work perfectly fine so.
- littlestymaar 3y ago
  You can get new satellite imagery ever day… (be it military ones if you're a major power, or just commercial one like your average OSINter)
  - hef19898 3y ago
    Sure. And then you have to upload those new, and vetted, imagines to all your drones. Other nav data is much more stable. Mind you, military hardware is not your smartphone, OTA updates are usually not a thong for various reasons. The approach for sure is interesting so.
    - magicalhippo 3y ago
      Well if you combine it with dead reckoning, I guess even a war torn field could be referenced against a pre-war image? I mean, a prominent tree along a stone wall might be sufficient to be fairly sure, if you at least got some idea of the area you're in via dead reckoning.

mytailorisrich 3y ago

Being able to nagivate using only a map stored locally sounds extremely useful in a war.

dwighttk 3y ago

Don’t we have basically this but it looks at stars?