Second European Physical Society Conference on Gravitation: measuring gravity

Session

Geodesy and Ranging

3

7 Jul 2021, 09:30

Conveners

Geodesy and Ranging

• Antonio Font Roda (chair)

Geodesy and Ranging

• Antonio Font Roda (chair)

59. Measuring Gravity in the Solar System

Luciano Iess (Universita' La Sapienza)

07/07/2021, 09:30

Geodesy and Ranging

talk

Gravity measurements are a crucial tool to peek through the surface of planetary bodies and reveal their interior structure. As a consequence of the equivalence principle, every gravity measurement in space must be a differential one, therefore requiring two test masses. Microwave links provide the observable quantities needed to follow the free fall of a probe mass (the spacecraft) in the...

41. Future costallations for observing Earth's time variable gravity field

Pieter Visser (Delft University of Technology)

07/07/2021, 10:00

Geodesy and Ranging

talk

Invited talk

60. Relativistic Geodesy Using Optical Clocks

Helen Margolis (National Physical Laboratory Teddington UK)

07/07/2021, 11:00

Geodesy and Ranging

talk

Optical atomic clocks have demonstrated unprecedented stability and estimated systematic uncertainty, far surpassing the current generation of caesium primary frequency standards. Large-scale efforts are underway to verify their uncertainty budgets by means of international comparisons using optical fibre networks or satellite-based frequency comparison techniques. Such comparisons, together...

42. Lunar and interplanetary laser ranging

Marco Muccino (LNF- INFN), Simone Dell'Agnello (LNF)

07/07/2021, 11:30

Geodesy and Ranging

talk

There are laser retroreflector arrays (LRAs) on the Moon since 50+ years ago (deployed by Apollo and Luna missions). There were no laser retroreflectors on Mars until microreflectors (of ~25 gr mass) were recently deployed on Mars (deployed by the InSight and Perseverance missions). These instruments are positioned using specialized ephemeris software (Planetary Ephemeris Program, from the...

61. The first interspacecraft laser ranging interfrometer on GRACE Follow-On and conclusions for future gravity missions

Malte Misfeldt (Max-Planck-Institute for Gravitational Physics)

07/07/2021, 12:00

Geodesy and Ranging

talk

The GRACE-FO twin satellites were launched in mid 2018 to continue the enormously useful Earth gravity field measurements from GRACE (2002-2017). The novel feature is the Laser Ranging Interferometer (LRI), which improves the noise of the inter-satellite separation measurement from 2 μm to 200 pm at high frequencies. The LRI was designed as an experimental demonstrator, but continues to work...