[G06-P] Poster

[G06-P-01] Assessing Precise Point Positioning Derived Zenith Total Delays Using the NIGNET

Omeiza Mayaki¹, ^○Marcelo Santos¹, Thaleia Nikolaidou¹, Chukwuma Okolie² (1.University of New Brunswick, 2.University of Lagos)

Global Navigation Satellite Systems (GNSS) is increasingly being used worldwide in operational meteorology with the estimation of parameters such as zenith total delay (ZTD). Due to its continuous evolution, precise point positioning (PPP) has become an increasingly used technique for estimating ZTD from GNSS data. Many nations utilize dedicated GNSS receiver networks as continuously operating reference stations (CORS) for operational weather and climate services. The focus of this research is to assess the quality of PPP derived ZTDs using data collected by the Nigerian GNSS Reference Network (NIGNET) and a local and nearby International GNSS Service (IGS) station. NIGNET is a network of fourteen stations equipped with GPS and GLONASS dual frequency capable receivers. Data collected from 1st January 2011 to 9th November 2016 is used in the assessment. The estimates are compared with ray-traced estimates from the global Numerical Weather Model (NWM) of the National Centre for Environmental Prediction (NCEP), and estimates from the IGS final troposphere product. A time series analysis is performed to access the level of agreement of the products and identify possible systematic effects arising from the different techniques. Results indicate a 3 cm root mean square value of the differences, and that the variation exhibited by the PPP ZTD estimates correlates with known annual weather patterns across the country.