The raw measurements API provides raw GNSS measurements so that somebody can implement their own position engine, and do things like RTK.
The corrections mentioned in the blog post are calculated by the phone (in Google Play Services, using Google's 3D building models) using the raw GNSS measurements, and provided back to the chipset to improve its position estimate (correcting for reflections and interference).
The corrections mentioned in the blog post are calculated by the phone (in Google Play Services, using Google's 3D building models) using the raw GNSS measurements, and provided back to the chipset to improve its position estimate (correcting for reflections and interference).