GPS Guidance Devices Used for Field Crops Spraying Machines

SUMMARY In order to reduce the environment pollution when u sing field crop spraying machines it is necessary to set the amount of substance corr ectly and to drive the machine very precise. GPS guiding devices is another new and important way to drive the aggregates correctly. The GPS devices use satellites (up to 20 satellites ) to determine the position of the aggregate. The movement and the deviation of the aggregate can be followed on the display mounted in the tractor cabin. Schematically, the operating principle of GPS is as follows: the receiver receives a message transmitted by a satellite; the receiver de termines the difference between current time and time at which the message was sent; the receive r calculates the distance between it and satellite, knowing that the signal was transmitted at light speed; the receiver receives another message from two other satellites and calculates th e distance between him and satellites; knowing the distance between him and three known points, the receiver calculates its position trilatera ţion method. The signal emitted by the satellites contains data that a receiver uses to calculate the satellite loc ation and make the necessary adjustments for precise positioning.