A Reverse Approach to Antenna Specifications for London Buses Next-generation Positioning System

摘要

A reverse approach to specification of a new GNSS antenna used next-generation bus transportation system for Greater London is presented. The approach is tagged "reverse" because we started from the performance requirements forecast by studying the Required Navigation Performance figure. Then we proceeded to compare it with the available capabilities of the current antenna. Finally, we obtain the specifications that should be fulfilled when searching for an antenna according to the performance entries on data sheet. The key to the whole evaluation and the suggestion process was to derive the formula predicting the receiver positioning performance with different antenna settings. In this regard, a universal receiver model was assumed and a set of critical characteristics of antenna was established. The results show that, with the constraint of cost, positioning performance may be enhanced through dual frequency with the recommended antenna by an order of magnitude, but some restrictions apply.