Abstract：Aiming at the problem that the threshold model is too conservative due to the non-Gaussian features of the CNR and CCD monitoring quantities in the signal quality monitoring(SQM) process, we propose a threshold algorithm for SQM based on stable distribution. Firstly, we give two threshold models based on Gaussian distribution, and then derive the threshold model of monitoring quantities based on stable distribution. Finally, we evaluate and verify the threshold algorithm based on stable distribution by the measured data. The results show that the stable distribution can more accurately describe the CNR and CCD monitoring quantities, making the threshold envelope the monitoring quantity parameters tighter, solving the problem of the practical threshold model being too conservative and insufficiently accurate, reducing the risk and improving the integrity of the GBAS system.
