Recently, earth observation system by using satellite network have attracted much attention due to their wide coverage and disaster resistance. Although the system is useful for collecting various data, which have an affect on a natural disaster, ecology and so forth, earth observation satellite hardly send the collected observation data to the ground station. This is because that the earth obs...

Abstract The ground station scheduling problem is a complex involving multiple objectives. Evolutionary techniques for multi-objective optimization are becoming popular among different fields, due to their effectiveness in obtaining set of trade-off solutions. In contrast some conventional methods, that aggregate the objectives into one weighted-sum objective function, evolutionary algorithms m...

The first space-based GPS augmentation systems were implemented using the L-band geostationary transponders launched on the Inmarsat-3 satellites. The Ground Uplink Station (GUS) hardware and software, which enables these “bent-pipe” transponders to broadcast pseudo-GPS signals, was developed by NAVSYS. The Ground Uplink Station equipment allows the Inmarsat-3 GPS augmentation signals to be pre...

Third generation mobile systems are gradually being deployed in many developed countries in hotspot areas. However, owing to the amount of new infrastructures required, it will still be some time before 3G is ubiquitous, especially in developing countries. One possible cost effective solution for deployments in these areas is to use High Altitude Platforms (HAPs) (Collela et al., 2000; Djuknic ...

[1] Under a NASA program to produce long-term data records from instruments on multiple satellites, data from a series of nine Solar Backscatter Ultraviolet (SBUV and SBUV/2) instruments have been reprocessed to create a coherent ozone time series. Data from the BUV instrument on Nimbus 4, SBUV on Nimbus 7, and SBUV/2 instruments on NOAA 9, 11, 14, 16, 17, 18, and 19 covering the period 1970–19...

Quantum cryptography and quantum computation are based on the communication of single quantum states and quantum entanglement, respectively. Particularly in view of these high potential applications the question arises, whether quantum correlations can be sufficiently well communicated over global distances to be used in communication protocols as predicted by quantum mechanics. Various experim...

| We examine the design of a communication link involving the data transfer from a small, low-orbit satellite to a ground station, but through a geostationary satellite. The advantage of this approach is that a single ground station , which tracks only the geostationary satellite, may be shared by a multiplicity of small satellites. Our goal is to select certain small satellite parameters { sig...

Optical communications can provide high-data-rate telemetry from deep-space probes with subsystems that have lower mass, consume less power, and are smaller than their radio frequency (RF) counterparts. However, because optical communication is more affected by weather than is RF communication, it requires groundstation site diversity to mitigate the adverse effects of inclement weather on the ...

An interference channel is a network consisting N senders and N receivers. There exists a oneto-one correspondence between senders and receivers. Each sender only wants to communicate with its corresponding receiver, and each receiver only cares about the information form its corresponding sender. However, each channel interferes the others. So an interference channel has N principal links and ...

suspended aerosols in the atmosphere have strong impact on the global climate. they influence the earth’s radiation budget by scattering or absorbing both incoming and outgoing radiation. aerosols in troposphere are caused by natural sources, such as dust, sea-spray and volcanoes and also by anthropogenic sources, such as combustion of fossil fuels and biomass burning activities and from gas-to...