Carrier phase delay altimetry with GPS-reflection/occultation interferometry from low Earth orbiters

GPS signals reflected off the surface of the Earth can be detected by receivers aboard occulting Low Earth Orbiters (LEOs). In this work, carrier phase interferometry between the reflected and direct occultation signals is performed to infer its relative delay at centimetric error. Our analysis shows that submeter sensitivity on the surface heights can formally be reached with this technique. The potential applications to polar ice altimetry are discussed.