Integer Ambiguity Estimation with the Lambda Method

High precision relative GPS positioning is based on the very precise carrier phase measurements. In order to achieve high precision results within a short observation time span, the integer nature of the GPS double difference ambiguities has to be exploited. In this contribution we concentrate on the integer ambiguity estimation, which is one of the steps in the procedure for parameter estimation, see section 2 in [2]. The integer ambiguity estimation will be carried out with the LAMBDA method. LAMBDA stands for Least-squares AMBiguity Decorrelation Adjustment. After applying a decorrelating transformation, a sequential conditional adjustment is made upon the ambiguities. As a result, integer least-squares estimates for the ambiguities are obtained.