Accuracy Evaluation of Estimated Ionospheric Delay of GPS Signals Based on Klobuchar and IRI-2007 Models in Low Latitude Region. - K. C. T. Swamy; A. D. Sarma; V. Satya Srinivas; P. Naveen Kumar; P. V. D. Somasekhar Rao (IEEE Geosci. Remote. Sens. Lett., 2013)