SLOW HOPPING DATA TRANSMITTER

A method and apparatus for coupling data from a base station to a rover unit for determining the position of the rover unit. Multiple radio channels are monitored by the base station and a radio channel is assigned that is unoccupied. A RTK message is then transmitted by the base station that includes the assigned radio channel. The rover unit then monitors the assigned radio channel for the next RTK message. The assigned radio channel is periodically updated. Each following RTK message is transmitted over a previously assigned radio channel. This results in both the base station and the rover unit “hopping” from channel to channel for communicating the RTK message from the base station to the rover unit. The rover unit uses the received RTK message, along with signals from a position determination system, for determining position.