The book consists of five chapters. The first covers basic concepts of parameter estimation in GNSS Geodesy. From there, Chapter 2 discusses reference systems in GNSS Geodesy. Chapter 3 moves on to observation models, errors, and biases, and Chapter 4, which is completely new to this second edition, details GNSS data processing workflow and strategies. The book concludes with an applied chapter that details concrete uses of GNSS Geodesy. New appendices that will be especially useful to seasoned users are also featured.