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Showing papers by "Animesh Maitra published in 2007"


01 Oct 2007
TL;DR: In this article, three phenomena were studied with the experimental data are rain attenuation, depolarization, and scintillation, and the presence of large rain drops was found to have a more dominant role in determining the extent of depolarisation than affecting the co-polar attenuation.
Abstract: Propagation measurements at Ku-band over an earth-space path have been carried out at Kolkata (22°34′ N, 88°29′ E) by receiving a signal at 11.172 GHz from the satellite NSS-6 (geostationary at 95°E). The amplitudes of the co-polar signal and the cross-polar component have been monitored along with the measurements of rain rate and drop size distribution by an optical raingauge and a Joss-type disdrometer, respectively. Three phenomena studied with the experimental data are rain attenuation, depolarization and scintillation. The rain attenuation observed experimentally tallies well with the values obtained from the point rain rate using a simple attenuation model, if the rain rate is low (less than 20 mm/h). The depolarization, indicated by an enhancement of the cross-polar component of the signal, is well correlated with the rain attenuation. The presence of large rain drops is found to have a more dominant role in determining the extent of depolarization than affecting the co-polar attenuation. The scintillation observations associated with the rain events indicate that the standard deviation of fast fluctuations increases with rain attenuation following a power-law.

27 citations


Proceedings ArticleDOI
24 Jul 2007
TL;DR: In this article, the effect of small scale irregularities associated with the rain events was studied using propagation measurements at 11.172 GHz from the satellite NSS-6 (geostationary at 95°E) since June 2004.
Abstract: Propagation measurements at Ku‐band over an earth‐space path have been carried out at Kolkata (22°34′N, 88°29′E) by receiving a signal at 11.172 GHz from the satellite NSS‐6 (geostationary at 95°E) since June 2004. The amplitudes of the co‐polar signal and the cross‐polar component have been monitored along with rain rate and drop size distribution measurements by an optical raingauge and a Joss‐type disdrometer, respectively. The relationship between rain attenuation over the earth‐space path and the rain rate gives an assessment of raining conditions along the satellite path. Fast fluctuations of the satellite signal amplitude are studied to indicate the effect of small scale irregularities associated with the rain events. TRMM satellite data obtained with PR and TMI indicate that the rain rate has a distinct control of rain height which increases with the former, the relationship depending on the type of rain. The propagation measurements and TRMM data have been used to study the features of rain at Ko...