Стандарт по сверхточному геопозиционированию GPS, предоставляемому военным службам, тоже полезная бумажка так-то. This document defines the levels of performance the U.S. government makes available to authorized users of the GPS Precise Positioning Service, also known as the military GPS service. https://www.gps.gov/technical/ps/2007-PPS-performance-standard.pdf