How to detect the floor/ground plane using unity Vuforia?

I am a newbie to vuforia, I am working on a project based on augmented reality. I wanted to detect the floor as a part of my project.

My question is there any other way to recognize the floor/ground plane other than using the option “Image target” like this

Thanks in advance.

This is an upcoming feature of Vuforia:

It is not released yet. You can use ARKit (iOS) or ARCore (Android) now.