| 摘要 |
The present invention relates to a method for generating accuracy information for an ionosphere model. For each of at least some of the phase observations having fixed or converged ambiguities, phase residual information of a parameter estimation procedure is obtained and coordinates of a pierce point on a sphere around the earth are computed. The sphere is defined by an ionosphere single layer model. The coordinates indicate where the path of the signals from which the phase observation has been obtained pierces the sphere. Then the phase residual information of the corresponding phase observation is mapped, for each pierce point, to the vertical at the pierce point to generate vertical residual information, Furthermore a grid of equidistant points (grid points) is put on the sphere and, for each of at least some of the grid points, pierce points are identified within a threshold distance from the grid point on the sphere. Then grid points are selected for which the number of identified pierce points exceeds a threshold number. For each selected grid point, vertical accuracy information is computed at the selected grid point based on the vertical residual information of the identified pierce points, and a scale factor is computed based on the vertical accuracy residual information computed for the selected grid point. Finally, the accuracy information for the ionosphere model is generated based on the vertical accuracy information computed for the selected grid points and an overall scale factor computed based on the computed scale factors. |
