The invention discloses a low-
orbit constellation phase retention parameter
estimation method, and belongs to the technical field of
satellite orbit control. According to the method, the
orbit semi-major axis measurement value output by
satellite-borne GNSS
orbit determination is not directly used, the
latitude argument measurement value with high precision is used for indirectly estimating the orbit semi-major axis flat root, the
orbit determination precision of an existing GNSS
receiver is not improved, the high-precision requirement of
satellite constellation maintenance on the orbit semi-major axis can be met, and the double-frequency GNSS
receiver with a higher price is prevented from being configured on a satellite; and after the relative
latitude argument measurement value is converted into the flat root, polynomial fitting is carried out, then polynomial fitting is carried out on the variation trend of the orbit semi-major axis flat root by utilizing the variation relationship between the relative
latitude argument flat root and the orbit semi-major axis flat root, and the fitting coefficient is calculated, so that the orbit semi-major axis flat root at any moment is indirectly estimated, the precision of the semi-major axis flat root is superior to 1m, and
constellation phase keeping can be completed based on a single-side drift ring control strategy under the condition that any semi-major axis attenuation rate is met.