# What is sensor drift?

From Wikipedia:

If the output signal slowly changes independent of the measured property, this is defined as drift

So my question is, if I have a gyroscope with sensor drift does that mean that $E\left\{f(x)\right\} \neq 0$ ? I have an excercise where it is written, that the sensor has drift but also that the $E\left\{f(x)\right\} = 0$. But to me one statement seems excludatory of the other one.

I assume you set the first momentum of your true measure to $\mu=0$, so your question actually reads
gyroscope with sensor drift does that mean that $E[f(x)] \ne \mu$?
The thing is that $f(x)$ is a random variable with non-zero variance and a time dependency. That means: If there's drift, that random variable is not a stationary process.