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An ensemble average method to estimate absolute TEC using radio beacon‐based differential phase measurements: Applicability to regions of large latitudinal gradients in plasma density
Author(s) -
Thampi Smitha V.,
Bagiya Mala S.,
Chakrabarty D.,
Acharya Y. B.,
Yamamoto M.
Publication year - 2014
Publication title -
radio science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.371
H-Index - 84
eISSN - 1944-799X
pISSN - 0048-6604
DOI - 10.1002/2014rs005372
Subject(s) - tec , ionosphere , total electron content , global positioning system , electric beacon , latitude , remote sensing , environmental science , geodesy , differential phase , meteorology , phase (matter) , physics , computer science , geology , telecommunications , geophysics , quantum mechanics
A GNU Radio Beacon Receiver (GRBR) system for total electron content (TEC) measurements using 150 and 400 MHz transmissions from Low‐Earth Orbiting Satellites (LEOS) is fabricated in house and made operational at Ahmedabad (23.04°N, 72.54°E geographic, dip latitude 17°N) since May 2013. This system receives the 150 and 400 MHz transmissions from high‐inclination LEOS. The first few days of observations are presented in this work to bring out the efficacy of an ensemble average method to convert the relative TECs to absolute TECs. This method is a modified version of the differential Doppler‐based method proposed by de Mendonca (1962) and suitable even for ionospheric regions with large spatial gradients. Comparison of TECs derived from a collocated GPS receiver shows that the absolute TECs estimated by this method are reliable estimates over regions with large spatial gradient. This method is useful even when only one receiving station is available. The differences between these observations are discussed to bring out the importance of the spatial differences between the ionospheric pierce points of these satellites. A few examples of the latitudinal variation of TEC during different local times using GRBR measurements are also presented, which demonstrates the potential of radio beacon measurements in capturing the large‐scale plasma transport processes in the low‐latitude ionosphere.