How Accurate is IMU?



Hi All,

I’m working on a project and would like to find the best way to keep track of my ROV’s position underwater. I’ve read through a handful of the threads here and noticed this is a very common problem people have tried to tackle.

Personally, I am trying to get some hard numbers on home much the measurements of the OROV IMU drift over time and how accurate it can be.

I also wanted to know if there are any other reasonable approaches or products to tracking the ROV’s position. Are there better IMU products approximately in the same price range or entirely better systems? I know acoustics and lasers are methods used to locate ROV’s and transmit data, but they don’t seem to very accessible outside the professional world just yet.

Any help is greatly appreciated! Thanks!


There are acoustic systems out there but I don’t know how accurate they really are and for $5000 you could buy a lot of other options.

Another option is to use a rotating sonar like the Humminbird 360 series. This would give you stationary 360 and moving side scan.


Thanks for the response Jim. As far as acoustic positioning goes - that seems to be about what I found from my research. There aren’t many platforms that are worth what they cost for a project of this scale.

I have not heard of using something like the Humminbird for positioning. Could you elaborate?

Otherwise, do you know how good OROV’s IMU is and if it can be used to get relatively accurate positioning? I have been in touch with them but have struggled to get any numbers in terms of value drift/error building.


My theory, and it is only a theory, is that given the known position of the sonar transducer, you can determine distance and direction from the sonar image of the ROV.