The paper presents a construction of a wireless hybrid data link operates applying two transmission channels using optical radiation (FSO – Free Space Optics) and radio one (RF - Radio Frequency). Based on some parameters (e.g. laser power, optics aperture, photodetector detectivity, signal bandwidth, beam divergence) of the link components, its data range was determined for various operating conditions (visibility and turbulence). Preliminary tests of the link prototype (TRL 6) were carried out at the Military Communication Institute, Poland. The results showed that the use of FSO/RF technology systems can provide the increase in data transmission security, link availability, and immunity to intentional interference. Considering the features of this technology, high applicable potential to military activities was observed.
Saturated hydrocarbons are mainly nontoxic, but as extremely flammable gases forming explosive mixtures with air. The Lower Explosive Level (LEL) for methane is 4.4%, which is very dangerous in the mining industry. Methane is also an asphyxiant gas causing coma or death. Therefore, continuous monitoring of the hydrocarbons concentration is very important. Optoelectronic methods are very attractive for this application, especially nondispersive infrared (NDIR) technique. It enables a direct, fast, and selective measurement of different gas concentrations. NDIR sensors have many advantages, which make them very promising for use as hydrocarbon detectors. Despite a lot of benefits, common used NDIR sensors have some disadvantages. They need periodic calibration and have limited detection range, from ~100ppm. These parameters can be improved thanks to modernization detection scheme and use of newest IR sources and detectors. During Analyses selected IR sources and detectors were taken into account. Absorption spectra of analyzed hyrdrocarbons were studied to minimize impact interfering gases like carbon dioxide and water.