Research On Integrity Airworthiness Compliance Technology For Airborne SBAS Receiver

The performance of the core satellite navigation system has been improved significantly since the advent of Satellite Based Augmentation System(SBAS).In the field of civil aviation,SBAS can produce more accurate positioning information to provide safer navigation services.Therefore,it is of great significance to conduct research on whether the performance of SBAS airborne equipment can meet the requirements of civil aviation airworthiness.Integrity is one of the four core indicators of navigation system.With reference to the technical standard RTCA DO-229 E,taking Wide Area Augmentation System(WAAS)as an example,the system composition and main error sources are introduced,and the error correction model in the WAAS broadcast enhanced messages are established.By analyzing the measured data such as navigation and enhanced messages from the medium round earth orbit(MEO)and geostationary orbit(GEO)broadcasting,the precision and integrity parameters,visible satellite performance,DOP,positioning error(XPE),protection leval(XPL)and alarm limit(XAL)are studied.Airworthiness compliance is studied against the GNSS performance index of ICAO.The fault error parameters of different orders of magnitude are configured at different times.According to the analysis of warning information sent by the system,the failure monitoring ability of SBAS is obtained and the fault star is detected and eliminated.According to the decoding of the message and the extraction of parameters,the airworthiness service performance can be obtained with good accuracy and integrity through calculation.The accuracy of each station meets the requirements of the LPV-200 approach;For integrity service performance,the local area 100% meets the requirements of the LPV-200 approach,and the monitoring stations in the marginal areas meet the requirements of the LPV approach except at individual moments.Fault detection can issue alarm information within the alarm time required during the precision approach(PA).Both failure time and size determine the impact on service performance;After FDE,the system performance is basically similar to that without failure.