Vertical TEC in the equatorial anomaly region from satellite altimetry data

The high-precision demands imposed by the ocean altimetry community of the late 1980 resulted in the TOPEX/Poseidon mission. This mission was the first to carry as its main instrument a dual-frequency sea-altimeter on board a satellite. This instrument together with other state-of-the-art technologies involved in the mission, led to sea-height determinations with precision better than 2 cm. As a by-product, the TOPEX/Poseidon mission provided vertical TEC determinations that since they became available, have demonstrated to be a powerful tool for ionospheric studies.