Presentation Information
[U16-P01]Next-generation satellite-based Earth gravity observations using emerging quantum technologies
*Yoshiyuki Tanaka1 (1.Earth and Planetary Science, The University of Tokyo)
Keywords:
gravity,geodesy,quantum,optical lattice clock,climate change
One of the essential components for realizing satellite-based Earth observation is a global reference frame. A reference frame provides a common standard for describing the positions of objects on Earth and in space and is determined with high precision using space geodetic techniques. The construction of such a frame requires continuous monitoring of ground reference stations and satellite positions, Earth rotation variations, and the Earth’s gravity field. As by-products of reference frame realization, observations of the solid Earth, atmosphere, oceans, and upper atmosphere have greatly benefited a wide range of Earth science disciplines.
Among these, satellite gravimetry—although less familiar in Japan—has undergone remarkable development in recent years. The U.S.–German GRACE mission, launched in the early 2000s, revolutionized observations of the ice sheets, oceans, terrestrial water storage, and atmosphere by measuring the spatiotemporal distribution of mass variations at the Earth’s surface. These observations have provided new data that contribute significantly to our understanding of global warming. At present, plans are underway in Europe and the United States to launch an additional pair of similar satellites, which would improve the temporal resolution of global gravity observations to only a few days.
As a next step, further improvements in measurement precision are being explored by equipping satellites with atom-interferometric accelerometers, and extensive simulation studies are actively being conducted. In addition, proposals have been made to install optical lattice clocks—whose accuracy exceeds that of the current SI second by more than two orders of magnitude—on Earth observation satellites. Based on general relativity, such clocks would enable measurements of Earth’s gravity through variations in the flow of time.
In this presentation, I will introduce recent advances in satellite gravimetry, including the application of emerging quantum technologies, and discuss their expected contributions to Earth science.
Among these, satellite gravimetry—although less familiar in Japan—has undergone remarkable development in recent years. The U.S.–German GRACE mission, launched in the early 2000s, revolutionized observations of the ice sheets, oceans, terrestrial water storage, and atmosphere by measuring the spatiotemporal distribution of mass variations at the Earth’s surface. These observations have provided new data that contribute significantly to our understanding of global warming. At present, plans are underway in Europe and the United States to launch an additional pair of similar satellites, which would improve the temporal resolution of global gravity observations to only a few days.
As a next step, further improvements in measurement precision are being explored by equipping satellites with atom-interferometric accelerometers, and extensive simulation studies are actively being conducted. In addition, proposals have been made to install optical lattice clocks—whose accuracy exceeds that of the current SI second by more than two orders of magnitude—on Earth observation satellites. Based on general relativity, such clocks would enable measurements of Earth’s gravity through variations in the flow of time.
In this presentation, I will introduce recent advances in satellite gravimetry, including the application of emerging quantum technologies, and discuss their expected contributions to Earth science.