Achieving high-accuracy relative positioning in real-time: system design, performance and real-time results

This paper covers the software and hardware concepts of a new, high-precision, real-time, differential-positioning system. The design objectives and operation principles for such the system are based on Leica´s Wild SR299. The design concept is for a user-configurable system, covering a wide range of accuracies from meter to centimeter-level. Low accuracies are accomplished with relative ease. High accuracies require a combination of carrier phase, pseudo range observations and integer ambiguity resolution. In contrast to post-mission algorithms the system runs autonomously with a minimum of user interaction. The system may be used for static baselines as well as for moving vehicles, and it is designed to deliver the best accuracies after minimum observation times. Results of positioning real-time tests are presented in conjunction with performance figures for the specified system. The tests were performed under various conditions including measurements in a moving environment. High accuracy was reached with fixing ambiguities on the fly in real-time