Based on the success of the previous four editions, this new fifth edition includes Global Navigation Satellite Systems (GNSS) in the title, which is part of the Global Positioning System (GPS). The book provides an introduction to the concepts needed to understand and use GPS and GNSS. Neither simplistic nor overly technical, the new edition is thoroughly updated with the changes in GPS and GNSS hardware, software, and procedures. It describes why modern GNSS positions can be acquired with more certainty, increased stability, and improved tracking in obstructed areas. The book offers a rare combination of knowledge and skills that every land surveyor needs to master.