Autonomous estimation of plasmasphere content using GPS measurements

Abstract

[1] The plasmasphere (also denoted as the protonosphere) is a large toroidal domain of light ionized particles situated above the ionosphere and confined by the Earth's magnetic field. While plasmaspheric charge densities are considerably less than those of the ionosphere, the large extent of the plasmasphere can produce significant charge column densities, or total electron content (TEC), for lines-of-sight passing through the plasmasphere. A method for Self-Calibration of Range Errors (SCORE) has been developed previously both to determine combined bias calibration values for GPS receivers and satellites and to calculate absolute TEC values for the ionosphere. An enhanced SCORE process, described here, retains the ''self-calibration'' feature of the original SCORE process, by not requiring any measurements beyond those performed by the GPS receiver system being calibrated. The enhanced SCORE process also determines a characteristic plasmasphere amplitude parameter, thus providing an autonomous determination of both the ionospheric and plasmaspheric TEC. Case studies for a nearequatorial site are presented, with model parameters derived from 1998 data being applied to determine ionospheric and plasmaspheric TEC for measurements made in 1999.

Kalman filter-based algorithms for monitoring the ionosphere and plasmasphere with GPS in near-real time

“…There are several studies investigating the plasmasphere using GPS data (e.g., Ciraolo and Spalla, 1997;Lunt et al, 1999c, d;Kelly, 1999;Mazzella et al, 2002;Otsuka et al, 2002;Belehaki et al, 2004;Carpenter, 2004;Izengaw et al, 2008;Manju et al, 2008;Carrano et al, 2008). Lunt et al (1999a) used model simulations to estimate the plasmaspheric electron content (PEC) at European and American mid-latitude sites for quiet magnetic conditions, at both solar maximum and minimum.…”

The nature of GPS differential receiver bias variability: An examination in the polar cap region

“…This leaves operators of middle-and low-latitude stations with a significant challenge in their bias estimation, as pTEC can exceed 10 TECU at those locations [Lunt et al, 1999a;Mazzella, 2009]. Jan, 2009Jan, 2010Jan, 2011Jan, 2012Jan, 2013 Date 30 This mechanism has been extensively researched in the works of Lunt et al [1999aLunt et al [ , 1999b, Mazzella et al [2002], and Mazzella [2009]. While this is a significant concern for midlatitude observations, the absence of an appreciable plasmasphere in the polar cap region [Lunt et al, 1999a;Nsumei et al, 2008] debunks this as a mechanism through which the observed biases, and thus the ISR-GPS comparisons, should vary at the Resolute site.…”

Development of a regional GPS-based ionospheric TEC model for South Africa

“…The daytime plasmasphere contribution to GPS-TEC is approximately ten percent, but increases to 20%-35% at night (Webb and Essex, 1997). Plasmaspheric TEC separated from GPS-TEC supplies a novel means of investigating plasmaspheric charged densities evolution and dynamics Mazzella et al, 2002;Belehaki and Jakowski, 2003). In the Grahamstown comparison, the MIDAS and ASHA solutions tracked the double peak better than the GIM (Fig.…”