Dynamic display of river boundary on electronic river chart

The river boundary of the electronic river chart need change over the actual water level. The remote sensing technology is applied to exact the river boundary data. The data is used to generate the river level of the rough gradient. The generated river level is saved in the data base of the electronic river chart. The current river level boundary is calculated by the unit circle rolling iterative algorithm. Experiment results show that the raised method processes calculates quickly, and its display effect is good.