4:30 PM - 4:45 PM
[G01-4-01] E-GRASP/Eratosthenes: a satellite mission for improving the Terrestrial Reference Frame
invited
The accuracy and stability of a Terrestrial Reference Frame (TRF) that are required to detect the smallest variations (e.g. sea level rise) in the Earth system components have been identified by GGOS and the scientific community to be 1 mm for positions and 0.1 mm/yr for velocities. These GGOS requirements are far from being met today, mainly due to deficiencies in the realization of the TRF originating from (1) the difficulty to accurately measure the local ties between the reference points (intersection of axes of large instruments, phase centers of antennas) and (2) the fact that each space geodetic technique suffers from its own systematic effects.
In order to fundamentally improve this situation, the E-GRASP/Eratosthenes satellite mission has been proposed to ESA as response to the 2017 Earth Explorer-9 (EE9) call. E-GRASP will provide a highly accurate co-location of all four space geodetic techniques (GNSS and DORIS receivers, laser retro-reflectors, and a VLBI transmitter) in space, on the same satellite platform, with particular attention paid to the time and space metrology on board. Orbiting the Earth in a highly eccentric orbit for visibility reasons, E-GRASP will be fully complementary to co-location on the ground and will connect all the ground stations with its co-located instruments.
Many different simulations have been performed already, both, for selecting the best orbital scenario according to many geometrical, technical and physical criteria and for assessing the impact on the TRF, which is crucial to achieve the GGOS requirements.
The presentation will focus on the mission science, the instrumentation and scenario as well as the simulation results available today.
In order to fundamentally improve this situation, the E-GRASP/Eratosthenes satellite mission has been proposed to ESA as response to the 2017 Earth Explorer-9 (EE9) call. E-GRASP will provide a highly accurate co-location of all four space geodetic techniques (GNSS and DORIS receivers, laser retro-reflectors, and a VLBI transmitter) in space, on the same satellite platform, with particular attention paid to the time and space metrology on board. Orbiting the Earth in a highly eccentric orbit for visibility reasons, E-GRASP will be fully complementary to co-location on the ground and will connect all the ground stations with its co-located instruments.
Many different simulations have been performed already, both, for selecting the best orbital scenario according to many geometrical, technical and physical criteria and for assessing the impact on the TRF, which is crucial to achieve the GGOS requirements.
The presentation will focus on the mission science, the instrumentation and scenario as well as the simulation results available today.