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Sure. You can transmit the sonar from a different location. A hidden sub could send out a drone to make the sonar pings from a different location. You'll be giv

Sure. You can transmit the sonar from a different location. A hidden sub could send out a drone to make the sonar pings from a different location. You'll be giving away the location of the drone, rather than the sub. There's still an issue around detecting that a sub is in the general vicinity, of course.

walrus01 4y ago
or more conventionally, you build a fleet of oceanographic survey ships which operate in the open navigating international waters, collecting vast data sets of bathymetric information... obviously not perfect yet. https://en.wikipedia.org/wiki/Pathfinder-class_survey_ship https://en.wikipedia.org/wiki/Pathfinder-class_survey_ship there is also the danger that a drone emitting sonar pings may be indistinguishable to a third party from a live torpedo, and makes it look like you're preparing to attack somebody you really don't want to start a war with (China, etc).
lazide 4y ago
Your drone would need to be really close to the sub to provide any useful information - so close that you’d definitely be exposing the submarines locations unless it was quieter than the sub. Which good luck with that. Any active sonar would likely paint the submarine anyway too for any passive sonar listeners. Overall, unlikely to be useful.
- throwaway09223 4y ago
  It could be a mile or more away.
  - lazide 4y ago
    How do you figure? RF (nor light) transmit effectively under water. How would it be useful to them at that distance?
    - throwaway09223 4y ago
      The sonar ping is what transmits over great distance - that's why it's used. The drone can transmit the ping and the sub can listen. If I'm hiding in the darkness I can send a drone out with a lightbulb to shine a light near what I want to see without revealing myself.
      - lazide 4y ago
        A mile is far, far too close then. A square mile of ocean is a VERY small search place compared to what they would start with. And how would the drone know to 'flash the flashlight' where it was useful to the sub without the sub somehow communicating to the drone? Which would require the sub to emit something, or preprogram it before release. Not to mention, unless the sub stayed in one place or somehow communicated with the drone, it would have to stay in one place to have any chance to recover it. Even then, odds of finding the hidden black spot on it’s own with inertial guidance aren’t great if it’s away for long. If it was programmed into the drone when it was launched, just the drone coming to and from the sub would draw a giant red line to and from the sub. It would also severely restrict the sub - it either has to program in a path, in which case the drone will illustrate where the sub WILL BE shortly, or it has to do a one-off, in which case anyone could listen to/follow the drone back to the sub when it's retrieved. Seems not very useful in practice, except as some kind of disposable thing during an attack for redirection or distraction.
        throwaway09223 4y ago
        A drone would be far less detectable than the sub itself when not pinging (the drone would have only electronics, no nuclear turbine), so that seems like a non-issue regarding detecting the drone while in silent running. Drones are a lot more quiet and harder to locate than nuclear subs. A programmed path wouldn't illustrate where the drone or sub will be in advance so that's also a non-issue. You only know where the ping came from, at the time the ping was sent. The drone could also simply surface and pick up new instructions from satellite. I assume we will soon be moving en masse to underwater drones for reasons far beyond what's discussed here.

walrus01 4y ago

or more conventionally, you build a fleet of oceanographic survey ships which operate in the open navigating international waters, collecting vast data sets of bathymetric information... obviously not perfect yet. https://en.wikipedia.org/wiki/Pathfinder-class_survey_ship https://en.wikipedia.org/wiki/Pathfinder-class_survey_ship there is also the danger that a drone emitting sonar pings may be indistinguishable to a third party from a live torpedo, and makes it look like you're preparing to attack somebody you really don't want to start a war with (China, etc).

lazide 4y ago

Your drone would need to be really close to the sub to provide any useful information - so close that you’d definitely be exposing the submarines locations unless it was quieter than the sub. Which good luck with that. Any active sonar would likely paint the submarine anyway too for any passive sonar listeners. Overall, unlikely to be useful.

throwaway09223 4y ago
It could be a mile or more away.
- lazide 4y ago
  How do you figure? RF (nor light) transmit effectively under water. How would it be useful to them at that distance?
  - throwaway09223 4y ago
    The sonar ping is what transmits over great distance - that's why it's used. The drone can transmit the ping and the sub can listen. If I'm hiding in the darkness I can send a drone out with a lightbulb to shine a light near what I want to see without revealing myself.
    - lazide 4y ago
      A mile is far, far too close then. A square mile of ocean is a VERY small search place compared to what they would start with. And how would the drone know to 'flash the flashlight' where it was useful to the sub without the sub somehow communicating to the drone? Which would require the sub to emit something, or preprogram it before release. Not to mention, unless the sub stayed in one place or somehow communicated with the drone, it would have to stay in one place to have any chance to recover it. Even then, odds of finding the hidden black spot on it’s own with inertial guidance aren’t great if it’s away for long. If it was programmed into the drone when it was launched, just the drone coming to and from the sub would draw a giant red line to and from the sub. It would also severely restrict the sub - it either has to program in a path, in which case the drone will illustrate where the sub WILL BE shortly, or it has to do a one-off, in which case anyone could listen to/follow the drone back to the sub when it's retrieved. Seems not very useful in practice, except as some kind of disposable thing during an attack for redirection or distraction.
      - throwaway09223 4y ago
        A drone would be far less detectable than the sub itself when not pinging (the drone would have only electronics, no nuclear turbine), so that seems like a non-issue regarding detecting the drone while in silent running. Drones are a lot more quiet and harder to locate than nuclear subs. A programmed path wouldn't illustrate where the drone or sub will be in advance so that's also a non-issue. You only know where the ping came from, at the time the ping was sent. The drone could also simply surface and pick up new instructions from satellite. I assume we will soon be moving en masse to underwater drones for reasons far beyond what's discussed here.