TITLE:
Feasible Multiple Satellite Mission Scenarios Flying in a Constellation for Refinement of the Gravity Field Recovery
AUTHORS:
Basem Elsaka
KEYWORDS:
Satellite Geodesy; Multi-Satellite Constellations (Bender; Cartwheel-4S; GRAPEN); Gravity Field Recovery
JOURNAL NAME:
International Journal of Geosciences,
Vol.5 No.3,
March
27,
2014
ABSTRACT: Improving
the gravity field recovery in terms of error levels and more isotropic noise
distribution by adding cross-track and radial information to the satellite observables
has been investigated through a number of studies by a variety of satellite
constellations, i.e. satellite pairs
that orbit the Earth in alternative configurations than the current GRACE
(Gravity Recovery And Climate Experiment) gravity mission. This contribution
gives for the first time a comparative study considering the recovery of the
global gravity field from three constellations flying in satellite pairs in
different directions (i.e. along-track, cross-track and radial). The three constellations include: 1) Foursatellite
Bender configuration (flying in two pairs) of type along-track observations, 2)
Three-satellite GRAPEN (combined GRACE with Pendulum formations) configuration
of type cross-alongtrack observations, 3) Four-satellite Cartwheel
configuration (flying in two pairs) of type radialalong-track observations.
Additionally, a GRACE mission scenario is added as a reference “comparative”
mission. The orbits of all satellites are considered to fly with drag-free
system, however, realistic white noise has been added to the simulated
observations to mimic the error associated with the drag-free measurement. The
results are analyzed in the spectral wavelength spectrum of the gravity field
up to a spherical harmonics degree of n = 100 and are plotted spatially on
earth maps. The results show that the Three-satellite GRAPEN constellation
provides, besides its low economically launches, an improved gravity field
solution with respect to the Four-satellite Bender and the Four-satellite
Cartwheel constellations.