Compressive sensing (CS) theory has opened up new paths for the development of signal processing applications. Based on this theory, a novel single pixel camera architecture has been introduced to overcome the current limitations and challenges of traditional focal plane arrays. However, video quality based on this method is limited by existing acquisition and recovery methods, and the method a...

Increasing complexity and costs of satellite missions promote the idea of looking for opportunities to extend the operational lifetime or to improve the performance of a satellite instead of simply replacing it by a new one. Satellites in orbit can severely be affected by ageing, limited fuel source, or degradation of their hardware components. Also the disposal of spacecraft after the end of l...

Using time-dependent linear perturbation theory, we evaluate the dynamical friction force on a massive perturber Mp traveling at velocity V through a uniform gaseous medium of density ρ0 and sound speed cs. This drag force acts in the direction −V̂ , and arises from the gravitational attraction between the perturber and its wake in the ambient medium. For supersonic motion (M ≡ V/cs > 1), the en...

We investigate the dynamical evolution of coplanar hierarchical two-planet systems where the ratio of the orbital semimajor axes α = a1/a2 is small. Hierarchical twoplanet systems are likely to be ubiquitous among extrasolar planetary systems. We show that the orbital parameters obtained from a multiple Kepler fit to the radial velocity variations of a host star are best interpreted as Jacobi c...

A second order implicit f Lorentz ion hybrid model with sub-cycling and orbit averaging has been developed to study low-frequency, quasi-neutral plasmas. Models using the full Lorentz force equations of motion for ions may be useful for verifying gyrokinetic ion simulation models in applications where higher order terms may be important. In the presence of a strong external magnetic field, prev...

In these notes we first offer an overview of two core areas in the dynamics of probability measure preserving systems, the Kolmogorov-Sinai theory of entropy and the theory of orbit equivalence. Entropy is a nontrivial invariant that, said simply, measures the exponential growth rate of the number of orbits in a dynamical system, a very rough measure of the complexity of the orbit structure. On...