The Coherent Electromagnetic Radio Tomography (CERTO) is a radio beacon which measures ionospheric parameters in coordination with ground receivers. CERTO provides global ionospheric maps to aid prediction of radio wave scattering. CERTO was developed by the Naval Research Lab and is one of the 4 experiment packages on PicoSAT

PicoSAT

PicoSAT, launched on September 30, 2001, is a real time tracking satellite picosatellite of the miniaturized satellite series. The name "PICO" combines the first letters of all four of its experiments . PICOSat series are designed for a minimum of one year of on-orbit operations. The name Picosat...

satellite. CERTO has near real time measurements of the ionosphere.