Characteristics of L-band (1.5Â GHz) and VHF (244Â MHz) amplitude scintillations recorded at Kolkata during 1996-2006 and development of models for the occurrence probability of scintillations using neural network

L-band (1.5 GHz) and VHF (244 MHz) amplitude scintillations observed from Kolkata (22.58°N lat, 88.38° E long, 32°N dip), over a solar cycle 1996-2006 are presented in this paper. Situated near the northern crest of the equatorial anomaly, it is an excellent platform for scintillation studies. Based on 11 years' data, an attempt is made to develop models of hourly percentage occurrence of scintillations for the rising and declining phases of solar cycle using Neural Network. The relation between fading rate at VHF with the S4 index at L-band is also investigated.