Topside Ionospheric Tomography Exclusively Based on LEO POD GPS Carrier Phases: Application to Autonomous LEO DCB Estimation

• Published in: Remote sensing (Basel, Switzerland) Vol. 15; no. 2; p. 390
• Main Authors: Hernández-Pajares, Manuel, Olivares-Pulido, Germán, Hoque, M. Mainul, Prol, Fabricio S., Yuan, Liangliang, Notarpietro, Riccardo, Graffigna, Victoria
• Format: Journal Article
• Language: English
• Published: Basel MDPI AG 01.01.2023
• Subjects: Accuracy; differential code biases; Earth orbits; Estimates; Global Navigation Satellite Systems; Global positioning systems; GPS; Ionosphere; ionospheric tomography; Kalman filters; Low earth orbit satellites; Low Earth Orbiting satellites; Low earth orbits; Orbit determination; Random variables; Receivers; Receivers & amplifiers; Satellite navigation systems; Signal processing; Tomography; Transmitters
• ISSN: 2072-4292; 2072-4292
• DOI: 10.3390/rs15020390

This paper presents a novel technique to estimate DCBs from GPS transmitters and receivers on-board Low Earth Orbit (LEO) satellites. The technique consists of obtaining the DCBs as residuals from the difference between the ionospheric combination of the code and the associated ionospheric delay. The ionospheric delay is computed with TOMION, a background-model-free ionospheric tomographic technique based on dual-frequency GPS carrier phase data only, and solved with a Kalman filter. Thus, DCBs are also estimated epoch-wise from the LEO Precise Orbit Determination (POD) GPS receiver as a secondary product. The results for GPS satellite DCBs, obtained exclusively from the three MetOp LEO POD GPS receivers over four consecutive weeks, are in full agreement (i.e., at the level of a few tenths of ns) with those reported independently with other techniques from hundreds of ground-based receivers exclusively, by JPL and CODE analysis centers.