Abstract: The dual frequency correlation method which is based on the relevant characteristic of dual frequency carrier phase measurement constructs the ambiguity error band to fix integer ambiguity quickly. However, the algorithm needs to set the pseudo-range measurement accuracy in advance, which results in a false ambiguity search scope or an ineffective filter efficiency easily. First, the information on the baseline length and the gaze vector is utilized to derive the double difference geometric correlation model in order to obtain the integer ambiguity search range quantitatively. Then, the relationship among the sparsity of integer ambiguity search space, carrier phase wavelength, length and bandwidth of the error band are analyzed. Finally, the search range of the wide lane ambiguity is regarded as the horizontal axis of the error band axis to strengthen the sparsity of the search space. Consequently, an improved single epoch ambiguity resolution algorithm based on the dual frequency correlation method is proposed. Compared with the original algorithm in the single epoch, experimental results show that the average constringent rate of single-dimensional ambiguity increases to 85.71%, that the average computational cost is reduced to 0.46%, and that the success rate is increased from 95.28% to 99.78%, which greatly improves the reliability of ambiguity solution.

Key words: dual frequency correlation method, error band, wide-lane combination, baseline length, integer ambiguity