Abstract:

In order to overcome the shortcomings of satellite clock bias(SCB) forecasting accuracy based on the grey model(GM(1,1)) parameters of least squares estimation in the case of large SCB fluctuations, this paper uses the least absolute deviations(LAD) to improve the GM(1,1). During the modeling process, the principle of minimizing the absolute sum of errors is used as the optimization principle. Aiming at the non-differentiable characteristics of the objective function, the linear programming method is used to estimate the model parameters of the GM (1, 1). In addition, the improved forecasting model is applied to the forecast of the SCB when the SCB fluctuates greatly, and the forecast results are compared with the results predicted by GM (1, 1).The results show that the prediction results of the GM (1, 1)-LAD are significantly improved compared with the GM (1, 1) in the case of large fluctuations in the SCB, which provides a new idea for high-precision SCB prediction.

Key words: SCB prediction, grey model, least square method, least absolute deviations, linear programming