NavCom Technology, a wholly owned subsidiary of Deere & Company), announced the availability of RTK Extend, a product feature that combines the capabilities of NavCom's StarFire global decimeter positioning system with its RTK positioning algorithms to overcome the problem of communication dropouts during survey projects.
Obstacles such as hills, trees and buildings can interrupt the communication link to the base station, thus preventing a traditional RTK system from producing a position fix. The RTK Extend feature overcomes this problem by continuously computing both RTK and StarFire solutions simultaneously. During periods of successful RTK operation, the system keeps the back-up StarFire solution locked to the RTK solution until needed. When a communication outage occurs, RTK Extend automatically transitions to the global StarFire solution and maintains RTK levels of accuracy for up to 15 minutes, thus eliminating the time consuming and costly alternatives of either moving the base station or installing signal repeaters. Once the communication link is restored, the system automatically switches back to the RTK corrections.
Source: NavCom Technology, Aug. 3, 2004