Temporal and spatial variability of the bias between TOPEX- and GPS-derived total electron content

Brunini, C.; Meza, Amalia; Bösch, Wolfgang

doi:10.1007/s00190-005-0448-z

Cited by 74 publications

(50 citation statements)

References 22 publications

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“…We conclude that systematic biases arise from T/J vTEC and result in a greater T/J vTEC than GNSS-derived vTEC. Although systematic biases in Figure 5a-d are somewhat different for different datasets, the bias magnitudes are consistent with previous investigations [18][19][20][21][22][23]. What is responsible for the different systematic biases of T/J vTEC?…”

Section: Discussionsupporting

confidence: 90%

“…The TOPEX, JASON1/JASON2/JASON3 missions all operate simultaneously at 13.575 GHz (Ku band) and 5.3 GHz (C band), flying at an identical orbit altitude (approximately 1336 km) with an inclination angle of 66 • and a period of 112 min [15,31,32]. By measuring the range on two different frequencies, the T/J altimeter can provide a direct vTEC VTEC T/J over the oceans (worst case of GNSS-derived vTEC) up to the T/J orbit altitude [17,22,33,34]. If Ku band ionospheric range correction is calculated as presented by Brunini et al [22], then the vTEC can be expressed as follows:…”

Section: Gnss-derived Vtec Data and Jason Vtec Datamentioning

confidence: 99%

“…By measuring the range on two different frequencies, the T/J altimeter can provide a direct vTEC VTEC T/J over the oceans (worst case of GNSS-derived vTEC) up to the T/J orbit altitude [17,22,33,34]. If Ku band ionospheric range correction is calculated as presented by Brunini et al [22], then the vTEC can be expressed as follows:…”

Section: Gnss-derived Vtec Data and Jason Vtec Datamentioning

confidence: 99%

“…Jee et al [15] compared GPS vTEC and T/J vTEC for 1998-2009, and reported a positive relative TEC difference (i.e., GPS vTEC > T/J vTEC) in the PEC contribution to the ionosphere, which was largest in the early morning sector (up to 100%). However, many studies have found that T/J vTEC has a positive systematic bias of 2-5 TECu above real ionospheric TEC values when compared to other independent sources (i.e., T/J vTEC > GPS vTEC) [17][18][19][20][21][22][23]. This is paradoxical because GPS satellite altitude (~20,000 km) is higher than that of T/J satellites (~1336 km); thus, GPS vTEC should be larger than T/J vTEC due to it including the plasmasphere contribution above the T/J satellite orbital altitude.…”

Section: Introductionmentioning

confidence: 99%

“…They concluded that systematic biases for T/J-LPIM were 2.5-3.0 TECu, and larger during equinox than during solstice periods. Brunini et al [22] believed that the positive bias was mainly caused by a combination of LPIM underestimation (at low latitudes) and T/J SSB correction (at mid-latitudes). Azpilicueta and Brunini [23] reported the constant bias on TOPEX vTEC was caused by miscomputing the ionospheric correction.…”

Section: Introductionmentioning

confidence: 99%

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Plasmaspheric Electron Content Inferred from Residuals between GNSS-Derived and TOPEX/JASON Vertical TEC Data

et al. 2018

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Abstract:The plasmasphere, which is located above the ionosphere, is a significant component of Earth's atmosphere, and the plasmasphere electron content (PEC) distribution is determined by different physical mechanisms to those of the ionosphere electron content (IEC). However, the observation for the PEC is very limited. In this study, we introduced a methodology (called zero assumption method, which is based on the assumption that PEC can reach zero) to extract the PEC over TOPEX/JASON (T/J) and global navigation satellite system (GNSS) overlapping areas. Results show that the daily systematic bias (T/J vertical TEC > GNSS-derived vertical TEC) for both low (2009) and high (2011) solar activity condition is consistent, and the systematic bias for JASON2 and JASON1 is different. We suggest that systematic biases predominantly arise from the sea state bias (SSB), especially the tracker bias. After removing the systematic bias, we extracted reliable PEC inferred from differences between GNSS-derived vertical TEC and T/J vertical TEC data. Finally, the characteristics of the plasmaspheric component distribution for different local times, latitudes, and seasons were investigated.

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Section: Discussionsupporting

confidence: 90%

Section: Gnss-derived Vtec Data and Jason Vtec Datamentioning

confidence: 99%

Section: Gnss-derived Vtec Data and Jason Vtec Datamentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

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Plasmaspheric Electron Content Inferred from Residuals between GNSS-Derived and TOPEX/JASON Vertical TEC Data

et al. 2018

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Characterization of the impact of GLONASS observables on receiver bias estimation for ionospheric studies

et al. 2016

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This study investigates the impact of including the Russian Globalnaya Navigazionnaya Sputnikovaya Sistema (GLONASS) and Global Positioning System (GPS) observables in the estimation of the GPS satellite and receiver interfrequency delay biases. Efforts to advance the total electron content accuracy are directly linked to improving the satellite and receiver bias estimation. This analysis is a preliminary assessment of the impact of including GLONASS observables in the bias estimation process. We analyze bias series from 84 globally distributed stations between 17 February 2015 and 31 March 2015. We find that inclusion of GLONASS observables in the biases retrieval algorithm systematically reduces receiver biases at 88% of the stations than when only GPS observables are used. The difference is <1.0 total electron content unit (TECU; 1 TECU = 1016 el m−2), which falls within the bias retrieval uncertainty. However, due to its systematic behavior it must be characterized and documented. We also compare the bias series between two centers, the Jet Propulsion Laboratory and the Center for Orbit Determination in Europe. Our analysis shows that the mean difference between the two centers varies from station to station, with a value <1.0 TECU for 57% of the stations, suggesting an excellent intercenter agreement. For the other stations, the differences can reach up to 5.0 TECU. Finally, the stability of the bias retrievals over time is latitudinally dependent. Low‐latitude and middle‐latitude stations exhibit systematically the largest and smallest scatter, respectively, whereas stations at high latitudes obtain intermediate values.

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High‐resolution station‐based diurnal ionospheric total electron content (TEC) from dual‐frequency GPS observations

2013

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[1] Total electron content (TEC) estimates derived from Global Navigation Satellite System (GNSS) signal delays provide a rich source of information about the Earth's ionosphere. Networks of Global Positioning System (GPS) receivers data can be used to represent the ionosphere by a Global Ionospheric Map (GIM). Data input for GIMs is dual-frequency GNSS-only or a mixture of GNSS and altimetry observations. Parameterization of GNSS-only GIMs approaches the ionosphere as a single-layer model (SLM) to determine GPS TEC models over a region. Limitations in GNSS-only GIM TEC are due largely to the nonhomogenous global distribution of GPS tracking stations with large data gaps over the oceans. The utility of slant GPS ionospheric-induced path delays for high temporal resolution from a single-station data rate offers better representation of TEC over a small region. A station-based vertical TEC (TEC V ) approach modifies the traditional single-layer model (SLM) GPS TEC method by introducing a zenith angle weighting (ZAW) filter to capture signal delays from mostly near-zenith satellite passes. Comparison with GIMs shows the station-dependent TEC (SD-TEC) model exhibits robust performance under variable space weather conditions. The SD-TEC model was applied to investigate ionospheric TEC variability during the geomagnetic storm event of 9 March 2012 at midlatitude station NJJJ located in New Jersey, USA. The high temporal resolution TEC results suggest TEC production and loss rate differences before, during, and after the storm.Citation: Çepni, M. S., L. V. Potts, and J. B. Miima (2013), High-resolution station-based diurnal ionospheric total electron content (TEC) from dual-frequency GPS observations, Space Weather, 11, 520-528,

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Temporal and spatial variability of the bias between TOPEX- and GPS-derived total electron content

Cited by 74 publications

References 22 publications

Plasmaspheric Electron Content Inferred from Residuals between GNSS-Derived and TOPEX/JASON Vertical TEC Data

Plasmaspheric Electron Content Inferred from Residuals between GNSS-Derived and TOPEX/JASON Vertical TEC Data

Characterization of the impact of GLONASS observables on receiver bias estimation for ionospheric studies

High‐resolution station‐based diurnal ionospheric total electron content (TEC) from dual‐frequency GPS observations

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