We study the well-known Maximum Independent Set (MIS) problem and introduce the notion of satellites of a node. Branching on nodes with satellites is extremely simple. Nevertheless, satellites can be used to overcome a couple of hard cases in previous algorithms. Together with the notion of mirrors, introduced by Fomin, Grandoni, and Kratsch, they can be used to solve MIS in time bounded by O(1...

We examine formation conditions for the Galilean satellites in the context of models of late-stage giant planet accretion and satellite-disk interactions. We first reevaluate the current standard, in which the satellites form from a ‘‘minimum mass subnebula ’’ disk, obtained by augmenting the mass of the current satellites to solar abundance and resulting in a disk mass containing about 2% of J...

This study addresses the potential contribution of the first pair of Galileo FOC satellites sent into incorrect highly eccentric orbits for geodetic and surveying applications. We began with an analysis of the carrier to noise density ratio and the stochastic properties of GNSS measurements. The investigations revealed that the signal power of E14 & E18 satellites is higher than for regular Gal...

Absract Magnetic actuation utilizes the mechanic torque that is the result of interaction of the current in a coil with an external magnetic field. A main obstacle is, however, that torques can only be produced perpendicular to the magnetic field. This actuation principle has been a topic of research since earliest satellites were launched. Magnetic control has been applied for nutation damping...

To reduce the sampling rate in global navigation satellite system (GNSS)-radio occultation receivers, it is essential to establish a suitable estimation of Doppler frequency from the received signal in the satellite onboard receiver. This receiver is usually located on low earth orbit satellite and receives GNSS satellites signal in the occultation situation. The occurred Doppler on the signal ...

Thanks to post-flight analyses of several artificial satellites carried out during last years, the meteoroids hazard for space navigation and in-orbit satellites permanence is now clear. Even if catastrophic impact is a rare event, high meteoroids fluxes can erode and weaken the satellite or space station main structures. However, the main danger seems to be the impact-generated plasma, which c...

one of the difficulties in using absolute altitudes is the separation between the mean open sealevel and geoid. theoretically, geoid is the base level in absolute altitudes, but practically, the mean open sealevel is used as a base level for absolute altitudes. the difference between these two levels is called as the seasurface topography. in this research, it is dealt the mean sea level modeli...