Determination of total electron content from differential Doppler records

Abstract

Several existing and new methods of determining total electron content ( I) from differential Doppler records obtained from orbiting satellites are examined. The relative accuracy of different methods is compared through simulated and actual examples. It is found that though in case of no- or linear gradients all the methods give same results, only the method based on minimum curvature of I( t) curves is reliable in general case.