Seacraft ENC3 Inertial navigation unit?

[scubaozy]

Simple dead reckoning imho. Not very hard to measure the speed or extrapolate it. You just need to measure amount of fluid running from a tube, like in aircraft pitot tube.

 

[sdavo]

Regarding GPS underwater - position would be triangulated using underwater beacons, rather than satellites. This may not be functional in shallow water near shore.

DARPA dives in to underwater navigation project -- Defense Systems

 

[-JD-]

Regarding GPS underwater - position would be triangulated using underwater beacons, rather than satellites. This may not be functional in shallow water near shore.

DARPA dives in to underwater navigation project -- Defense Systems

OK, not GPS but " " GPS " " (Just to be clear, those are air-quotes )

 

[tursiops]

Should work fine in a quarry, with no currents....

 

[scubaozy]

I develop navigation sw for living. If I had to guess;

1. You get gps position for the entry,
   
2. Start recording sensor(s) data
3. Detect using accelerometer when diver is swimming or engaging the power. Do simple dead reckoning with 2 preset speed values for different states and compass. Consider changes adjusting the position when diver is swimming up or down. This is basically extrapolating current position.
4. You get a gps fix for the exit position.
5. Now that start and end positions are known, interpolate the recorded geometry and simplify to fit into start/end points.

It should not be difficult to add manually a current estimation (direction-speed) prior to entry or exit.

 

[Michael Perdue]

For those interested in what can be achieved with low grade consumer IMU’s, this is a good read.
Accelerometers and gyroscopes: fantasy vs. reality

I’ve been working with high end navigation and tactical grade IMU’s for the last 20years. IMHO we are a long long way off from having a navigation solution based primarily off Inertial data at this price point.

I’m unconvinced that this system old perform well in a hand held configuration, but I expect that this system would perform better than a lot of people might think if used on a scooter with a properly calibrated compass and flow meter.

 

[divingx]

Does anyone know how's Suex new SINAPSI compared to ENC3 in terms of navigation?

 

[Valyngar]

Does anyone know how's Suex new SINAPSI compared to ENC3 in terms of navigation?

Anyone used sinapsi yet?

 

[Must_dash]

It's a basic INS system, same as a plane.
Starts with a know position (GPS) then uses the other sensors to calculate direction, depth etc. This is a screen shot from nav download from a training dive last week.

 

[stuartv]

It's a basic INS system, same as a plane.
Starts with a know position (GPS) then uses the other sensors to calculate direction, depth etc. This is a screen shot from nav download from a training dive last week.

So, it compensates for current (which the ENC3 does not)?