Simultaneous observations of the main trough using GPS imaging and the EISCAT radar

Abstract

Abstract. Images of the winter-time ionosphere over Northern Scandinavia in January 2002 from two independent experimental techniques are presented. In the first case, observations of differential phase delay from the GPS satellites are used in an inversion algorithm, called MIDAS (Multi Instrument Data Analysis Software), to estimate the spatial distribution of electron concentration. The second approach uses the European Incoherent Scatter (EISCAT) radar situated near Tromsø in northern Norway to gather independent data for comparison with the MIDAS images. The EISCAT data are plotted as "fan plots" that show electron concentration as a function of latitude and range, whilst the MIDAS results are presented in the form of latitude-altitude crosssections at the locations and times coincident with the radar scans. Wide-area maps of Total Electron Content (TEC) are also shown for the post-noon period. The position and time evolution of the trough seen in the MIDAS images is confirmed by four scans of the EISCAT radar in the afternoon period. The results demonstrate that GPS imaging is capable of locating the main trough, and confirm the potential of MIDAS imaging as a tool for routine monitoring of the ionosphere.

Comparison of temporal fluctuations in the total electron content estimates from EISCAT and GPS along the same line of sight

“…Satellite data can indeed be used for 3-D imaging on either regional or global scales, while present EISCAT profiling is limited to narrow regions and to specific temporal windows with different sensing geometries (see for example a comparative study in Meggs et al, 2005). The modelling of structured features such as those described here might equip tomography reconstruction algorithms with higher resolution, which is needed to infer the physics of the observed phenomena.…”

History, current state, and future directions of ionospheric imaging

“…ISRs have been very important in ionospheric physics because they provide a wealth of information about the ionosphere such as density, temperature, and velocity of the medium. This can be important for the interpretation of ionospheric images [ Meggs et al , 2005] by helping to distinguish between processes that change the bulk electron density within a region, such as precipitation and convection.…”

Reconstruction of Storm‐Time Total Electron Content Using Ionospheric Tomography and Artificial Neural Networks: A Comparative Study Over the African Region

“…The ionospheric TEC and electron concentration are good indicators of the morphology of the ionosphere and can therefore be used for ionospheric studies and satellite applications (Mitchell & Spencer, 2003). There exist a number of studies related to ionospheric tomography imaging based on an inversion algorithm, namely Multi-Instrument Data Analysis System (MIDAS; Chartier et al, 2014;Dear & Mitchell, 2006;Giday et al, 2016;Jayawardena et al, 2016;Materassi & Mitchell, 2005;Meggs et al, 2005;Mitchell & Spencer, 2003;Muella et al, 2011;Rose et al, 2014;Yin et al, 2004). Using data from a network of GPS receivers over the U.S. midlatitudes, it has been proven that MIDAS can produce images of electron concentration and TEC during extreme geomagnetic conditions (K p = 9) that are in good agreement with observations (Yin et al, 2004).…”

“…MIDAS ionospheric tomographic imaging results were mainly focused on the midlatitudes (Chartier et al, 2012;Dear & Mitchell, 2006;Giday et al, 2016;Meggs et al, 2005;Rose et al, 2014;Yin et al, 2004). The few works that are related to ionospheric imaging for the low-latitude region were done for geomagnetically quiet conditions (Chartier et al, 2014;Materassi & Mitchell, 2005;Muella et al, 2011).…”