Laser and Radio Tracking for Planetary Science Missions - A Comparison

Abstract

At present, tracking data for planetary missions largely consists of radio observables: range-rate range and angular position. Future planetary missions may use Interplanetary Laser Ranging (ILR) as a tracking observable. Two-way ILR will provide range data that are about 2 orders of magnitude more accurate than radio-based range data. ILR does not produce Doppler data, however. In this article, we compare the relative strength of radio Doppler and laser range data for the retrieval of parameters of interest in planetary missions, to clarify and quantify the science case of ILR, with a focus on geodetic observables. We first provide an overview of the near-term attainable quality of ILR, in terms of both the realization of the observable and the models used to process the measurements. Subsequently, we analyze the sensitivity of radio-Doppler and laser-range measurements in representative mission scenarios. We use both an analytical approximation and numerical analyses of the relative sensitivity of ILR and radio Doppler observables for more general cases. We show that mm-precise range normal points are feasible for ILR, but mm-level accuracy and stability is unlikely to be attained, due to a combination of instrumental and model errors. ILR has the potential for superior performance in observing signatures in the data with a characteristic period of greater than 0.33-1.65 hours This indicates that Doppler tracking will typically remain the method of choice for gravity field determination and spacecraft orbit determination in planetary missions. Laser ranging data, however, are shown to have a significant advantage for the retrieval of rotational and tidal characteristics from landers. Similarly, laser ranging data will be superior for the construction of planetary ephemerides and the improvement of solar system tests of gravitation.

arXiv commentAccepted for publication in Journal of Geodesy

References in corpus (17)

• The Confrontation between General Relativity and Experiment
• The IAU 2000 resolutions for astrometry, celestial mechanics and metrology in the relativistic framework: explanatory supplement
• INPOP08, a 4-D planetary ephemeris: From asteroid and time-scale computations to ESA Mars Express and Venus Express contributions
• Lunar laser ranging: the millimeter challenge
• Spacecraft VLBI and Doppler tracking: algorithms and implementation
• General post-Minkowskian expansion of time transfer functions
• Advancing Tests of Relativistic Gravity via Laser Ranging to Phobos
• Odyssey: a Solar System Mission
• On the contribution of PRIDE-JUICE to Jovian system ephemerides
• Planetary Radio Interferometry and Doppler Experiment (PRIDE) technique: A test case of the Mars Express Phobos fly-by
• Observations and analysis of phase scintillation of spacecraft signal on the interplanetary plasma
• Experimental Design for the LATOR Mission
• Astrometry of Cassini with the VLBA to Improve the Saturn Ephemeris
• Laser Ranging for Gravitational, Lunar, and Planetary Science
• Space-time Dynamics Estimation from Space Mission Tracking Data
• Impact analysis of the transponder time delay on radio-tracking observables
• LETSGO: A spacecraft-based mission to accurately measure the solar angular momentum with frame-dragging

Cited by in corpus (6)

• Methods for coherent optical Doppler orbitography
• Propagation and Estimation of the Dynamical Behaviour of Gravitationally Interacting Rigid Bodies
• Is there a semi-molten layer at the base of the lunar mantle?
• Modeling Optical Key Distribution over a Satellite-to-Ground Link Under Weak Atmospheric Turbulence
• Exploring the Interior Structure and Mode of Tidal Heating in Enceladus
• Bounds on the photon mass via the Shapiro effect in the solar system