No, F2FS is not meant for bare NAND and doesn't do wear-levelling. It is meant for cheap flash media such as USB flash drives, SD cards, eMMC and such. Those devices have controllers that perform wear-levelling and other flash-translation layer functions. They present as block devices just like SSDs and regular hard drives.
Conventional filesystems such as ext4 are optimized for spinning-rust and have to manage things like the fact that random access takes a significant amount of time while it has to wait for the next sector to come underneath the read/write head. With flash media, the seek time is zero but erasing a block takes a long time. There are of course many other differences. F2FS is designed to exploit the advantages of flash media and cope with the disadvantages.
That said, I don't think I'd want to run F2FS on an SSD. SSDs have sophisticated controllers that try to compensate for the advantages and disadvantages of flash media with respect to conventional filesystems. I think you'd wind up with F2FS fighting it out with the SSD controller and I think perform would suffer as a consequence.
... the ocean might simply be good at blocking transmissions.
The ocean isn't just good at blocking transmissions. It's ridiculously good at blocking radio waves. If you work the math on this page, you can see that your basic WiFi transmission (at 2.4 GHz) will experience an attenuation of almost 1700 dB/meter! At that rate you'd get far less than a millimeter of penetration.
Even the lowest frequency short wave bands (1.8 MHz) get 46 dB/meter attenuation. It starts to get possible to receive RF when you get down in the kHz range but of course, your data rate goes to hell.
For underwater communications under a couple hundred meters or so you can use an acoustic modem. Even then, your best data rate is going to be on the order 2400 baud or less.
If you want high speed underwater communications, you gotta use a cable.
The sub uses GPS for positioning on and near the surface. The rest of the way it's using inertial navigation.
USL@NOC is also working on multibeam sonar so that the robot can assess its position using geologic features on the bottom (up to about 200m away I expect) for position keeping in a current.
I'm not sure why they'd use a multi-beam for station keeping when they already have an ADCP (Acoustic Doppler Current Profiler) on board. The particular ADCP they're using here was made by a company I used to work for (in fact, I wrote a lot of the firmware in that sucker) and is accurate to within a few tenths of a percent and can track the bottom out to 200m.
6 months was barely enough for me to see Eastern and Southern Africa. You might be able to do it if all you're interested in is name-checking but if you really want to see some of the world you'll have to either spend a lot more time or limit your trip a little. If you want to visit Everest base camp and you've got six months, try going from India to Thailand via Nepal. I think you'll have a lot more fun if you take it slower.
As far as carrying a laptop with you, keep in mind that while internet cafes are plentiful, places with Wi-Fi or even an Ethernet connection might not be. For my trip to Africa I used Apple's Camera Connector to download my pictures to my iPod and used internet cafes to update my blog. It worked for me.
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No, F2FS is not meant for bare NAND and doesn't do wear-levelling. It is meant for cheap flash media such as USB flash drives, SD cards, eMMC and such. Those devices have controllers that perform wear-levelling and other flash-translation layer functions. They present as block devices just like SSDs and regular hard drives. Conventional filesystems such as ext4 are optimized for spinning-rust and have to manage things like the fact that random access takes a significant amount of time while it has to wait for the next sector to come underneath the read/write head. With flash media, the seek time is zero but erasing a block takes a long time. There are of course many other differences. F2FS is designed to exploit the advantages of flash media and cope with the disadvantages. That said, I don't think I'd want to run F2FS on an SSD. SSDs have sophisticated controllers that try to compensate for the advantages and disadvantages of flash media with respect to conventional filesystems. I think you'd wind up with F2FS fighting it out with the SSD controller and I think perform would suffer as a consequence.
... the ocean might simply be good at blocking transmissions.
The ocean isn't just good at blocking transmissions. It's ridiculously good at blocking radio waves. If you work the math on this page, you can see that your basic WiFi transmission (at 2.4 GHz) will experience an attenuation of almost 1700 dB/meter! At that rate you'd get far less than a millimeter of penetration.
Even the lowest frequency short wave bands (1.8 MHz) get 46 dB/meter attenuation. It starts to get possible to receive RF when you get down in the kHz range but of course, your data rate goes to hell.
For underwater communications under a couple hundred meters or so you can use an acoustic modem. Even then, your best data rate is going to be on the order 2400 baud or less.
If you want high speed underwater communications, you gotta use a cable.
The sub uses GPS for positioning on and near the surface. The rest of the way it's using inertial navigation.
USL@NOC is also working on multibeam sonar so that the robot can assess its position using geologic features on the bottom (up to about 200m away I expect) for position keeping in a current.
I'm not sure why they'd use a multi-beam for station keeping when they already have an ADCP (Acoustic Doppler Current Profiler) on board. The particular ADCP they're using here was made by a company I used to work for (in fact, I wrote a lot of the firmware in that sucker) and is accurate to within a few tenths of a percent and can track the bottom out to 200m.
6 months was barely enough for me to see Eastern and Southern Africa. You might be able to do it if all you're interested in is name-checking but if you really want to see some of the world you'll have to either spend a lot more time or limit your trip a little. If you want to visit Everest base camp and you've got six months, try going from India to Thailand via Nepal. I think you'll have a lot more fun if you take it slower.
As far as carrying a laptop with you, keep in mind that while internet cafes are plentiful, places with Wi-Fi or even an Ethernet connection might not be. For my trip to Africa I used Apple's Camera Connector to download my pictures to my iPod and used internet cafes to update my blog. It worked for me.