Research of complete set GPS/ГЛОНАСС-of equipment on an establishment of accuracy of coordination of points in mode RTK in various conditions of supervision, for the purpose of expediency of application of this equipment in zemelno-cadastral and other mass land worksis described. The factors influencing easing of signals transferred with companions are consid-ered. Formulas according to accuracy of calculation of the areas of the ground areas and recom- mended accuracy of record of the area taking into account its limiting error are offered.