In this paper a long-range wireless mesh network system is presented. It consists of three main parts: Remote Terminal Units (RTUs), Base Terminal Units (BTUs) and a Central Server (CS). The RTUs share a wireless network transmitting in the industrial, scientific and medical applications ISM band, which reaches up to 64 Km in a single point-to-point communication. A BTU controls the traffic wit...

Ka-band (32-GHz) radio communication links are more adversely affected by atmospheric noise temperature than X-band (8.4-GHz) or S-band (2.9-GHz) links. As a result, the strategy for telecommunications between a spacecraft employing Ka-band and the Deep Space Network is necessarily different from that employed at the lower frequencies. To aid in the development of new communication strategies, ...

This paper discusses the possibility to use spaceborne X-band radar interferometry for forest height mapping. In our previous works was shown that airborne X-band SAR interferometry combined with accurate ground elevation model can provide good estimates of boreal forest height. In order to apply this technique to spaceborne SAR images, temporal variability of the scattering and lower signal to...

The reconfigurable antenna based on RF-MEMS is hot researching direction in recent years,it can change electric parameters,such as radiation pattern,working band, input impedance, polarization diversity ,and so on. reconfigurable antenna of multi-band and multi-mode can replace multiple antennas based on one vehicle,decreases the developing price,size and weight of antennas,which is very import...

This paper describes a program of experiments conducted by the CSHCN using ACTS. This program of three experiments commenced in 1992 and utilized the ACTS T1-VSAT terminal. The experiments were motivated by the commercial driver of low-cost receive-only satellite terminals that can operate in a hybrid network environment. The first experiment tested highly adaptive methods of satellite bandwidt...

Conventionalmicrostriplowpass and bandpass filters such as stepped-impedance filters, open-stub filters, semilumped element filters, endand parallel-coupled half-wavelength resonator filters, hairpin-line filters, interdigital and combline filters, pseudocombline filters, and stub-line filters are widely used in many RF/microwave applications. Modern RF and microwave communication systems, spec...

Traditionally a majority of the commercial satellite communications systems have been fixed repeaters at C-band and Ku-band. The satellite industry is presently undergoing significant changes in the types of systems that are being fielded. New low earth orbit and geo stationary mobile systems have large numbers of flexible beams at either L-band or S-band through the use of large phased array a...

Now-a-days wireless communication has made the world a smaller than it used to be a couple of decades ago. With the evolving technologies emerging, a continuous and seamless connectivity with the artificial planetary objects such as Satellite and ground station has become a demand of time. Hence researchers are relentlessly working on to overcome the challenge of integrating a budget-friendly y...

In this paper, we present a system that models the land-mobile satellite communication channel with a Markov chain approach supported by images of the mobile Earth station’s (MES) environment. Our method employs a video camera with a fish-eye lens capturing image sequences of the user environment from the position of the moving MES, image and signal processing algorithms to recognize propagatio...

__________ Many mobile satellite systems have been proposed to employ Code Division Multiple Access (CDMA) technique at L/S band. These bands have been allocated to the mobile satellite services on a primary basis since 1992, in addition to the existing services. Therefore, the mobile satellite services will be subject to share spectrum with each other and with existing services. This paper dis...