IONOLAB products, resulting from the modelling and estimation of ionospheric propagation delay and variance maps, are designed to provide global ionosphere data coverage through the analysis of GNSS data collected by a monitoring network of public GNSS stations (IGS and EUREF).
There are three crucial aspects in the process of generating real-time global ionospheric map:
- Deriving slant total electron content (STEC) from GNSS raw observations
- Estimating satellite/station differential code bias (DCB) for calibration of TEC measurements
- Modeling and interpolating TEC measurements to obtain the global vertical total electron content (VTEC) over regular grids.
In particular, IONOLAB analysis is made of the following steps:
- The acquisition of input data from the network of sensor stations, mainly navigation data and observations collected from a network of IGS and EUREF GNSS reference stations (code-range and carrier-phase multi-frequency measurements).
- Receiver observation data is subject to pre-processing analysis and several quality control checks to exclude outliers and corrupted data.
- The IONOLAB engine is capable to estimate the receiver and satellite biases to properly calibrate the raw TEC measurements and improve the accuracy of the slant ionospheric delay.
- Then, calibrated TEC (Total Electron Content) measurements are verticalized and interpolated to obtain final ionospheric products.