Abstract: A precision positioning AGM system is provided for detecting the location of an AGM device, as well as the time of a smart pig passing the location. The practice combines two processes into one by using a GPS receiver at the AGM location to record raw GPS measurements at each AGM location. A second GPS receiver is provided at a remote known base location. These position signals and a pig-passage time signal from the AGM provide high accuracy positioning and pig passage time, with only one crew being required. These signals are broadcast to a remote monitoring site. This makes real-time pig tracking unnecessary and eliminates the need for more than one crew visiting the same site.