SibNet — Siberian Global Navigation Satellite System Network: Current state

In 2011, ISTP SB RAS began to deploy a routinely operating network of receivers of global navigation satellite system signals. To date, eight permanent and one temporal sites in the Siberian region are operating on a regular basis. These nine sites are equipped with 12 receivers. We use nine multi-frequency multi-system receivers of Javad manufacturer, and three specialized receivers NovAtel GPStation-6 designed to measure ionospheric phase and amplitude scintillations. The deployed network allows a wide range of ionospheric studies as well as studies of the navigation system positioning quality under various heliogeophysical conditions. This article presents general information about the network, its technical characteristics, and current state, as well as the main research problems that can be solved using data from the network

WTEC: A new index to estimate the intensity of ionospheric disturbances

We propose a new index, WTEC, to estimate the level of ionospheric disturbances from Global Navigation Satellite Systems (GNSS) data. The index is calculated based on dual-frequency phase measurements from single GNSS receiver. An index value exhibits the average intensity of the total electron content (TEC) variations over specified periods in the restricted area above a single GNSS receiver and reflects, mainly, the level of Wave activity in TEC (WTEC). The index has been shown to well detect the ionospheric disturbances of different origin and can be used as an efficient indicator for the ionospheric state. We believe that the proposed index has a great potential for ionospheric research: from studying isolated events at a local point to analyzing long data series and creating global maps of ionospheric disturbances. Keywords: Ionosphere, TEC, Ionospheric disturbance index, GNS

Estimating the total electron content absolute value from the GPS/GLONASS data

When determining the absolute oblique total electron content (TEC) of the ionosphere using both GLONASS/GPS code and phase measurements, there occurs a systematic error associated with the differential code biases (DCBs). A 1-ns DCB leads to the ∼2.9 TECU error when determining L1-L2 dual-frequency oblique TEC. We have developed an algorithm for DCB estimation from the data of a single GPS/GLONASS station. Presented are the results of the algorithm operation compared with the oblique TEC correction by using CODE laboratory DCB data

Estimating the absolute total electron content based on single-frequency satellite radio navigation GPS/GLONASS data

We present a new technique for estimating the absolute vertical and slant total electron content (TEC). The estimation is based on single-frequency joint phase and pseudorange GPS/GLONASS measurements at single stations. Estimated single-frequency vertical TEC agrees qualitatively and quantitatively with the dual-frequency vertical TEC. For analyzed stations a typical value of the difference between the single-frequency vertical TEC and dual-frequency ones generally does not exceed ~ 1.5 TECU with RMS up to ~ 3 TECU

Variability of GPS/GLONASS differential code biases

While estimating ionospheric total electron content (TEC) using both pseudorange and phase GPS/GLONASS data, there occurs a systematic error caused by the difference in processing times of L1 and L2 signals through radio frequency paths of satellites and receivers, known as differential code biases (DCBs). A 1-ns DCB causes an ∼2.9 TECU error in TEC estimation. Along with systematic DCB variations, seasonal variations, most likely related to variations in the receiver environment (temperature, humidity), also exist for some receivers and can reach in some cases up to ∼20 TECU