Inter-satellite clock offsets adjustment based on closed-loop residual detection of BDS inter-satellite link

It is a common and effective method in engineering science to use the "closed-loop detection" idea to detect and correct the cumulative error of system measurement. This paper indicates the favorable closed-loop conditions in the global inter-satellite link (ISL) of BeiDou-3 navigation satellite system (BDS-3), and proposes to detect and analyze the closed residuals. On this basis, a network adjustment model of the closed residuals is constructed by which the correction of inter-satellite clock offsets is realized. Calculations based on the on-orbit measured data indicate that the obvious constant or periodic non-zero closed residuals really exist in the global ISL of BDS-3. Attributed to the correction of the closed-loop residuals of the ISL, the non-closed inter-satellite clock corrections are basically eliminated, the random noise of the inter-satellite clock corrections is reduced by 30% to 50% and the accuracy of the inter-satellite clock corrections are effectively improved. It is helpful forthe service capability of BeiDou