Understanding the impacts of all forms of space weather on modern technologies and applications is becoming increasingly important. Gravity waves, Travelling Ionospheric Disturbances (TIDs) and plasma turbulence in the ionosphere are well understood to adversely impact applications that rely on trans-ionospheric radio propagation, such as radar surveillance, satellite communications and Global Positioning System (GPS) applications. TIDs are known to originate from explosive events, both at high altitudes, such as the 2013 Chelyabinsk meteor explosion, and at low altitudes, such as the 2011 Tohoku earthquake. Using Total Electron Content (TEC) observations from GPS receivers, TIDs have recently been reported in the literature to have travelled around the world several times due to the Tonga volcano eruption in January, 2022. In the present analysis, GPS TEC data is analysed in the context of the ionosonde data collected around Australia in the period around the Hunga Tonga–Hunga Ha`apai volcano eruption. It is reported that the gravity waves from the eruption caused the onset of ionospheric spread F events across Australia, lasting a number of hours at each station location. The impact of these spread F events on GPS Precise Point Positioning (PPP), particularly in terms of the PPP solution convergence time, is explored.