The Lambda-method for Fast Gps Surveying
نویسندگان
چکیده
Fast and high precision relative GPS positioning based on short observation time span data is possible, when reliable estimates of the integer double difference ambiguities can be determined in an efficient manner. In the present contribution it will be shown how this can be achieved by means of the Least-squares AMBiguity Decorrelation Adjustment (LAMBDA). The method was introduced in [Teunissen, 1993] and consists of two steps: (a) a decorrelation of the double difference ambiguities; and (b) a sequential conditional least-squares based search. The decorrelation is based on an integer approximation of the conditional least-squares transformation. Through the decorrelation, the spectrum of sequential conditional ambiguity variances is flattened and lowered, and a dramatic improvement in ambiguity precision is reached. Both the theoretical and practical intricacies of the method will be reviewed.
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