CORS networks: Absolute antenna models are absolutely vital

Abstract

Continuously Operating Reference Station (CORS) networks are being introduced across Australia and internationally. They provide improved access to positioning infrastructure for a wide range of Global Navigation Satellite System (GNSS) applications, in industries such as surveying, agriculture, mining and construction. Benefits include the rationalisation of infrastructure, establishment of multi-user systems, uniform positioning services, and consistent and reliable connectivity to the national datum. They can also provide a degree of legal traceability for satellite-based positioning. Antenna models are vital to CORS network operators, but often these are not fully understood by CORS users. To achieve maximum benefit from this technology, users need to apply the appropriate antenna models at their Real Time Kinematic (RTK) rover and in post processing. The good news is that, once implemented, the models take care of all the complexity, enabling the user in the field to focus on the GNSS survey at hand. After all, CORS network services should be accurate, reliable and easy to use! But users should also be aware of the negative effects when antenna models are ignored, or inappropriate models are applied at the rover. This article explains why the so-called ‘absolute’ antenna models are vital when data from CORS networks is used for high-accuracy positioning.