Online user‐friendly slant total electron content computation from IRI‐Plas: IRI‐Plas‐STEC

Abstract

Slant total electron content (STEC), the total number of free electrons on a ray path, is an important space weather observable. STEC is the main input for computerized ionospheric tomography (CIT). STEC can be estimated using the dual‐frequency GPS receivers. GPS‐STEC contains the space weather variability, yet the estimates are prone to measurement and instrument errors that are not related to the physical structure of the ionosphere. International Reference Ionosphere Extended to Plasmasphere (IRI‐Plas) is the international standard climatic model of ionosphere and plasmasphere, providing vertical electron density profiles for a desired date, time, and location. IRI‐Plas is used as the background model in CIT. Computation of STEC from IRI‐Plas is a tedious task for researchers due to extensive geodetic calculations and IRI‐Plas runs. In this study, IONOLAB group introduces a new space weather service to facilitate the computation of STEC from IRI‐Plas (IRI‐Plas‐STEC) at http://www.ionolab.org. The IRI‐Plas‐STEC can be computed online for a desired location, date, hour, elevation, and azimuth angle. The user‐friendly interface also provides means for computation of IRI‐STEC for a desired location and date to indicate the variability in hour of the day, elevation, or azimuth angles. The desired location can be chosen as a GPS receiver in International GNSS Service (IGS) or EUREF Permanent Network (EPN). Also instead of specifying elevation and azimuth angles, the user can directly choose from the GPS satellites and obtain IRI‐Plas‐STEC for a desired date and/or hour. The computed IRI‐Plas‐STEC values are presented directly on the screen or via e‐mail as both text and plots.

Space weather studies of IONOLAB group

“…Although the IRI-Plas can be used as a background model in CIT, computation of STEC from IRI-Plas is a tedious task for researchers due to extensive geodetic calculations and IRI-Plas runs. An important SW service from IONOLAB group is the online computation of STEC from IRI-Plas as IRI-PLAS-STEC at www.ionolab.org [12]. The IRI-PLAS-STEC can be computed online for a desired location, date, hour, elevation and azimuth angle.…”

Regional model‐based computerized ionospheric tomography using GPS measurements: IONOLAB‐CIT

“…In this study, the underlying ionospheric model is chosen to be IRI‐Plas, available at http://ftp.izmiran.ru/pub/izmiran/SPIM/http://ftp.izmiran.ru/pub/izmiran/SPIM/. The model‐based STEC is computed from IRI‐Plas as IRI‐Plas‐STEC as discussed in detail in Tuna et al []. IRI‐Plas‐STEC is provided online as a space weather service at www.ionolab.org.…”

“…In the IRI‐Plas‐STEC computation, STEC value on a slant path s , between a receiver‐satellite pair, is estimated by integrating the electron density as a nonuniform Riemann sum over voxels that are traced on path s [ Tuna et al , ]. In order to reduce the computational cost required for calculation of STEC values for all receiver‐satellite pairs in a GPS receiver network, electron density in each voxel can be computed using IRI‐Plas and stored in a database.…”

Performance of Solar Proxy Options of IRI‐Plas Model for Equinox Seasons

“…IONOLAB group has been using IRI‐Plas as a background ionosphere model in the development of various HF communication (Sezen et al, ), High Frequency (HF) ray tracing and propagation (Erdem & Arikan, ), Computerized Ionospheric Tomography (Erturk et al, ; Tuna et al, ), and 1‐D and 2‐D imaging (Arikan et al, ; Arikan, Shukurov, et al, ; Tuna et al, ) algorithms. IRI‐Plas has also been offered as an online Space Weather service at http://www.ionolab.org with a user‐friendly interface (Arikan, Sezen, et al, ; Sezen et al, ).…”

“…The most recent version of IRI includes two new model options for the peak ionization height of F2 layer, hmF2, and a revised representation of topside ion densities at very low and high solar activities . IONOLAB group has been using IRI-Plas as a background ionosphere model in the development of various HF communication (Sezen et al, 2013), High Frequency (HF) ray tracing and propagation (Erdem & Arikan, 2017), Computerized Ionospheric Tomography (Erturk et al, 2009;Tuna et al, 2015), and 1-D and 2-D imaging Arikan, Shukurov, et al, 2016;Tuna et al, 2014) algorithms. IRI-Plas has also been offered as an online Space Weather service at www.ionolab.org with a user-friendly interface (Arikan, Sezen, et al, 2016;Sezen et al, 2017).…”