RTK+ system for precise navigation in shadowed areas

We have developed a Real Time Kinematic (RTK) navigation system that uses pseudolite signals in addition to the GNSS satellite signals. This RTK+ system can be used under shadowed conditions where satellite signals alone do not provide satisfactory availability or performance. Such conditions exist for example under a large harbor crane, where continuous positioning of straddle carriers handling the containers would be very useful for logistics. Single-frequency test results of RTK+ show decimeter-level accuracy and rapid initialization of carrier ambiguities when the receiver moves. The results are considerably better than could be obtained with single-frequency RTK using satellite signals only. European Conference of Postal and Telecommunications Administrations (CEPT) is preparing a regulatory framework for the use of outdoor pseudolites. It is expected that it will open the way for commercial deployment of RTK+.