Observations of Scintillations and TEC at Palampur Himachal Pradesh beyond the Northern Crest of the EIA

A dual-frequency GPS receiver has been operational at the Department of Physics, Sri Sai University, Palampur ( 320 N, 760 E) installed by the Space Weather and Satellite Beacon Group of the Institute of Radio Physics and Electronics, University of Calcutta, Calcutta on April 1, 2014 as part of a collaborative research program. The location of the station is beyond the northern crest of the EIA and very few ionospheric measurements are available in this region. This region is characterized by sharp latitudinal gradients of ionization, much greater than the equatorward gradient of EIA. The receiver output consists of time in UT, satellite elevation, azimuth, ionospheric Total Electron Content (TEC) and amplitude scintillation index S4. TEC was analyzed for satellite links above an elevation of 60 to eliminate the effects of sharp spatial gradients of ionization existing in this region. S4 records were analyzed above an elevation of 15 in order to remove the effects of multipath. Post-sunset amplitude scintillations were noted on April 2014 the whole month from this station. We got peak of the amplitude scintillation S4 (0.5-1) are 12 events and UTC range is 11: 00-11: 52 for 11 events and for one it is 10: 46. S4 (0.2-0.5) are 3 events and UTC range is 11: 10-11: 15 for 2 events and for one it is 6: 16. S4 (1-2) are 9 events and UTC range is 11: 00-11: 52 for 11 events and for one it is 10: 46, pre-midnight local time hours respectively. It is important to note that all the satellite links showing scintillations were located south of the station near the northern crest of the EIA.