Analysis of dynamic response requirements for GNSS landing systems

An important issue in the development of future Global Navigation Satellite System (GNSS) Landing Systems (GLSs) is the dynamic response characteristics of GLS airborne equipment. To be compatible with existing airborne systems which use the Instrument Landing System (ILS), it is desirable for the dynamic properties of the GLS guidance signal to be equivalent to ILS. Specific concerns include dynamic tracking capability, frequency response characteristics, and sampled-data issues. This paper develops a methodology for modeling carrier-smoothed code GLS dynamic response characteristics. Comparing GLS characteristics with ILS requirements shows that not all ILS requirements can be met. However, a detailed autoland simulation evaluation of trade-offs in GLS dynamic response characteristics show that ILS-equivalent landing system performance can still be achieved