Carrier-Code Levelling (CCL) based TEC Estimation for a single Navigation with Indian Constellation (NAVIC) station

Abstract

Estimating the ionosphere with the global Navigation satellite system (GNSS) involves the ionospheric observable retrieval from the ionospheric parameter estimation (TEC) from the ground based stations. Carrier code leveling plot for NavIC satellites in August 2016 is considered which is a smoothed signal, in which the delay is less compared to the VTEC plots. At 11th hour it shows maximum VTEC with 12 TECU. In this observation, maximum 48TECU  is appeared at 11.30 am with slow variations in TEC from 40 to 48 within time from 10.00 to 11.30 am, compared to all satellites it gives very slow variations in VTEC. In order to reduce the multipath error and the observation noise CCL method uses the carrier phase to level the pseudorange. Leveling errors are caused by the CCL method.