141,028 research outputs found
On the Juno Radio Science Experiment: models, algorithms and sensitivity analysis
Juno is a NASA mission launched in 2011 with the goal of studying Jupiter.
The probe will arrive to the planet in 2016 and will be placed for one year in
a polar high-eccentric orbit to study the composition of the planet, the
gravity and the magnetic field. The Italian Space Agency (ASI) provided the
radio science instrument KaT (Ka-Band Translator) used for the gravity
experiment, which has the goal of studying the Jupiter's deep structure by
mapping the planet's gravity: such instrument takes advantage of synergies with
a similar tool in development for BepiColombo, the ESA cornerstone mission to
Mercury. The Celestial Mechanics Group of the University of Pisa, being part of
the Juno Italian team, is developing an orbit determination and parameters
estimation software for processing the real data independently from NASA
software ODP. This paper has a twofold goal: first, to tell about the
development of this software highlighting the models used, second, to perform a
sensitivity analysis on the parameters of interest to the mission.Comment: Accepted for publication in MONTHLY NOTICES of the Royal Astronomical
Society 2014 October 31. Received 2014 July 28; in original form 2013 October
Computational capacity of the universe
Merely by existing, all physical systems register information. And by
evolving dynamically in time, they transform and process that information. The
laws of physics determine the amount of information that a physical system can
register (number of bits) and the number of elementary logic operations that a
system can perform (number of ops). The universe is a physical system. This
paper quantifies the amount of information that the universe can register and
the number of elementary operations that it can have performed over its
history. The universe can have performed no more than ops on
bits.Comment: 17 pages, TeX. submitted to Natur
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