Many many inquiries about granny ripple pattern determined me to find the solution for you. Below you will find the Granny diagram which is very helpful to get exactly this blanket from below picture and tutorial
The pattern is free and called unique blanket by Yolanda Soto Lopez on ravelry. Photo doesn't bring you to pattern. Search it on ravelry.( as per some comments this pattern is no longer free). If anyone does have a link or the pattern please do share.