The distribution of satellite galaxies about isolated host galaxies in the second data release of the Sloan Digital Sky Survey (SDSS) is investigated. Host–satellite systems are selected using three different methods, yielding samples of ∼ 2100 satellites, ∼ 1300 satellites, and ∼ 650 satellites. All three samples of satellites show highly significant deviations from isotropy relative to the ma...

In this paper, a novel method for selecting a navigation satellite subset for a global positioning system (GPS) based on a genetic algorithm is presented. This approach is based on minimizing the factors in the geometric dilution of precision (GDOP) using a modified genetic algorithm (MGA) with an elite conservation strategy, adaptive selection, adaptive mutation, and a hybrid genetic algorithm...

The differential code bias (DCB) in satellites of the Global Navigation Satellite Systems (GNSS) should be precisely corrected when designing certain applications, such as ionospheric remote sensing, precise point positioning, and time transfer. In the case of COMPASS system, the data used for estimating DCB are currently only available from a very limited number of global monitoring stations. ...

We have surveyed the Hill sphere of Mars for irregular satellites. Our search covered nearly the entire Hill sphere, but scattered light from Mars excluded the inner few arcminutes where the satellites Phobos and Deimos reside. No new satellites were found to an apparent limiting red magnitude of 23.5, which corresponds to radii of about 0.09 km using an albedo of 0.07.

A fractionated spacecraft is a system comprising of a cluster of wirelessly communicating satellites, each with sensors, embedded processors, data storage, attitude control and propulsion. These clusters have several advantages over monolithic satellites: they offer redundancy, the economy of smaller satellites and resource sharing. However, there are other challenges beyond those of distribute...

The introduction of AIS will change maritime surveillance in the future. We explore how satellites can complement or extend this cooperative surveillance technique. Radar satellites alone are not sufficient. Micro-satellites carrying sensors for reception of navigation radar pulses or AIS signals offer some promising options.

Using high-resolution cosmological hydrodynamical simulations of Milky Way-massed disk galaxies, we demonstrate that supernovae feedback and tidal stripping lower the central masses of bright (−15 < MV < −8) satellite galaxies. These simulations resolve high-density regions, comparable to giant molecular clouds, where stars form. This resolution allows us to adopt a prescription for H2 formatio...