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.The orbital configuration of the satellite provides a sparse vTEC sample distribution that limits the studies of the vTEC distribution at a regional or global scale. In this contribution we present several mapping techniques, mostly based on the combination of data for time periods of several days and the use of proper coordinate systems, that help to overcome this problem leading to a better use of the information contained in TOPEX vTEC measurements about the main characteristic of the vTEC behavior, particularly in the equatorial anomaly region. This work also contains an application example in which the techniques were applied.