Airworthiness Testing Environment Simulation For GLS Airborne Receiver

As for the increasing number of civil aviation airplanes,the original instrument landing system can no longer meet the requirements of airport capacity and positioning accuracy.The GNSS landing system(GLS)is developed as an enhance or a replacement of the instrument landing system(ILS).Nevertheless,it is necessary to pass the airworthiness test to ensure that its function and accuracy can meet the needs of navigation.This article takes the GLS airborne receiver error environment as the topic,focuses on the development of ionosphere,troposphere,and multipath model and the test platform.The article firstly introduces the components and working principle of the Ground-based landing system.According to the airworthiness requirements of airborne equipment and relevant regulations of DO-253,Minimum operational performance standards for GBAS airborne equipment,we obtain the performance verification method of the airborne receiver.The external error simulation environment which needs to be considered in the test platform construction is determined.According to the relevant standards,the relative errors such as clock error,antenna phase center deviation,ionospheric error,tropospheric error,and multipath error are the basic elements of test environment.The simulation models are determined,and their feasibility is verified by the study of their conditions and characteristics.In order to ensure the authenticity of the simulation,a more accurate multipath model is established,and verified,including airport layout,obstacles,aircraft shape,airborne antenna model,and ground station external environment and reference antenna model.Finally,the test platform is built,and validated by the measured data of the atmosphere delay products provided by IGS.The test platform is based on the Web client and is able to release test reports.