| 主权项 |
1. A method for generating a quality measure for a frequency set for indicating the quality of said frequency set for use in a multi frequency ranging method, said frequency set comprising at least a primary frequency (F0), a first frequency (F1), and a second frequency (F2), said multi frequency ranging method being a method for estimating the range to an object by determining at least a first phase difference and a second phase difference in a received reflected echo signal and processing said first phase difference and said second phase difference, said first phase difference being the phase difference between the primary frequency (F0′) and the first frequency (F1′) in the received reflected echo signal and said second phase difference being the phase difference between the primary frequency (F0′) and the second frequency (F2′) in the received reflected echo signal, wherein said method for generating a quality measure comprises the steps of:
determining the smallest distance between any two range lines of a set of range lines in an N-dimensional phase space, wherein the N-dimensional phase space comprises at least a first dimension representing the first phase difference, and a second dimension representing the second phase difference, said N-dimensional phase space having a dimension equal to the number of phase differences used by the multi frequency ranging method, said range lines representing all theoretical possible combinations of the first phase difference, the second phase difference, and potential further phase differences, used by said multi frequency method, each point on a range line corresponding to a specific range to an object within the unambiguous range of the multi frequency ranging method; determining a quality measure for said specific frequency set based on the determined smallest distance. |
