Working from home - how does management gauge your productivity?

I have a huge opportunity here to steer management in the right direction for everyone on my team so I appreciate your input.

The company I work for is beginning to bring my team back into the office while also allowing some who wish (and are able to perform their duties) to continue working remotely. Currently, we send our manager a daily productivity report that lists out what we've done throughout the day and that's about it. Now that permanent remote work is becoming a reality for our company, my manager is telling us he needs better visibility into our productivity. When I asked him how productivity is better measured when I am in a cubicle, he couldn't give an answer (all but admitting that management has always gauged productivity by seeing butts in seats). Now that corporate is ratifying a remote work policy, managers/VPs are required to submit an outline of what that will look like for their department(s) - forcing them to concede that their current metrics are unsubstantial.

So now to my question:
How is is your remote-work productivity measured, and is it accurate without being obtrusive?