5 ms·

The three main methods are: acoustic using SONAR to receive data, tether or umbilical cord, and buoy based where the DSV releases a buoy that ascends to the top

The three main methods are: acoustic using SONAR to receive data, tether or umbilical cord, and buoy based where the DSV releases a buoy that ascends to the top. Relays don't really work because you'd need a LOT of them and they'd all have to keep themselves positioned within like 30 meters of each other which is very hard with ocean currents. That's with very low bandwidth VLF radio.

moffkalast 3y ago
Kinda weird that they didn't have an optical cable tether tbh.
- bg46z 3y ago
  Would be extremely heavy and very brittle
  - rootusrootus 3y ago
    There are deep sea submersibles designed to go a good bit deeper than Titanic which have optical tethers.
- denlekke 3y ago
  wouldn't it basically need to be the same as what they use for intercontinental cables ? tons of shielding and repeaters. maybe there'd be further risk bc if it breaks at the ship it could fall on or weigh down the submersible
  - moffkalast 3y ago
    Not at all. Shielding against what? It's light. You only need enough of a protective coat to make sure it's stiff enough to not twist and stretch too much and to make it neutrally buoyant. No repeaters needed, base range is about 40-60 km. ROVs going to greater depths use them all the time without major issues. The real reason is that they were stingy as fuck and that it's mildly impractical which outweighed their complete disregard for safety.
  - akira2501 3y ago
    > intercontinental cables Those also carry electrical power to supply the inline repeaters on those cables. If the cable does not have repeaters, it wouldn't need this, and the shielding could be greatly reduced.
agumonkey 3y ago
dumb question, are there positioning system for sea exploration ? I assume GPS dies off quickly but maybe something else ?
- civilitty 3y ago
  ROVs usually use a ultrashort baseline acoustic positioning system [1] paired with the surface vessel. [1] https://en.wikipedia.org/wiki/Ultra-short_baseline_acoustic_positioning_system https://en.wikipedia.org/wiki/Ultra-short_baseline_acoustic_...
- saberdancer 3y ago
  They have inertial navigation system.

moffkalast 3y ago

Kinda weird that they didn't have an optical cable tether tbh.

bg46z 3y ago
Would be extremely heavy and very brittle
- rootusrootus 3y ago
  There are deep sea submersibles designed to go a good bit deeper than Titanic which have optical tethers.
denlekke 3y ago
wouldn't it basically need to be the same as what they use for intercontinental cables ? tons of shielding and repeaters. maybe there'd be further risk bc if it breaks at the ship it could fall on or weigh down the submersible
- moffkalast 3y ago
  Not at all. Shielding against what? It's light. You only need enough of a protective coat to make sure it's stiff enough to not twist and stretch too much and to make it neutrally buoyant. No repeaters needed, base range is about 40-60 km. ROVs going to greater depths use them all the time without major issues. The real reason is that they were stingy as fuck and that it's mildly impractical which outweighed their complete disregard for safety.
- akira2501 3y ago
  > intercontinental cables Those also carry electrical power to supply the inline repeaters on those cables. If the cable does not have repeaters, it wouldn't need this, and the shielding could be greatly reduced.

agumonkey 3y ago

dumb question, are there positioning system for sea exploration ? I assume GPS dies off quickly but maybe something else ?

civilitty 3y ago
ROVs usually use a ultrashort baseline acoustic positioning system [1] paired with the surface vessel. [1] https://en.wikipedia.org/wiki/Ultra-short_baseline_acoustic_positioning_system https://en.wikipedia.org/wiki/Ultra-short_baseline_acoustic_...
saberdancer 3y ago
They have inertial navigation system.