Atmospheric ducts. Their applications in radio frequency propagation using satellite remote sensing techniques

      Аннотация: Atmospheric ducts are of great importance to study. These ducts tend to bend radio signals. The applications based on radio signal propagation through atmosphere are subjected to errors and inaccuracies. These applications may include satellite pointing, RADAR detection, location identification, etc. In this study formation of tropospheric ducts and propagation of RF signals through these ducts have been investigated over Pakistan, India, Afghanistan & related countries using satellite-sensed data during January 2009 to December 2012. Existence of ducts over large areas in Pakistan is found in different months. We have discussed ducts seasons (spring, summer, autumn, winter) in this study. Large ducts have been found in the month of November followed by March and April. The month of October is found with minimum ducts. Most ducts occur over south eastern parts of Pakistan. This study has also dealt with types of ducts with respect to wave propagation. Mostly super refractive ducts exist in all months over study period. Normal and sub refractive ducts are seen only in the month of October. Permanent ducts existence over study areas has also been discussed.

Ключевые слова: electrical engineering, satellite communication, atmorspheric refraction, ducting, atmorspheric ducts