Computational Aspects of the LAMBDA Method for GPS Ambiguity Resolution

Precise relative positioning based on a short observa- tion time span yields ambiguities that are heavily cor- related, together with position estimates of poor preci- sion. For an efficient estimation of the integer values of the GPS double difference ambiguities, the LAMBDA method has been developed and applied since 1993. In the context of the LAMBDA method, from a compu- tational point of view, there are various ways to arrive at the so-called ‘fixed solution’, in which the ambigui- ties are constrained to their integer values. Depending on the application at hand, it will be shown which way is most appropriate. This will be demonstrated with the help of a number of examples, both static and kinematic. The results show that efficient ambiguity resolution can be achieved very fast, on-the-fly (OTF), in a variety of cases, such as with roving receivers and in network sce- narios.