The Arag Navigator LT is a route guidance system with built-in GPS. The GPS uses GLONASS satellites. These have a very good coverage, allowing this device to work well between buildings or in wooded areas. The field perimeter can be displayed on this GPS device. This is then very clearly shown graphically on the display. The field is shown in green, the area around it is shown in brown. In addition, it is possible to calculate the surface area of the field after drawing the perimeter. This device also visualises the progress. Untreated areas are shown in dark green, treated areas are shown in light green.