Comparisons of Amplitude Scintillation Index Derived from 1-Hz BDS C/N₀ Measurements Released by Different Types of GNSS Receivers

Currently there are various Global Navigation Satellite System (GNSS) receivers designed for monitoring ionosphere scintillation phenomena. These receivers are usually based on different hardware designs and use different methods to process raw data. When using simultaneous amplitude scintillation observations released by different GNSS receivers, it is necessary to assess whether their calculated amplitude scintillation index (S<inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">4</inf> index) are same under identical scintillation conditions. This study has compared the S<inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">4</inf> index derived from the 1-Hz BDS () carrier-to-noise density ratio <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$(C/N_{0})$</tex> measurements of B<inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">lI</inf> signal (1561.098 MHz) and B<inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2I</inf> signal (1207.14 MHz) released by two types of receivers installed at Guilin <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$25.29^{\circ}\mathrm{N}, 110.33^{\circ}\mathrm{E}$</tex>; geomagnetic: <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$15.89^{\circ}\mathrm{N}, 177.19^{\circ}\mathrm{W}$</tex>). One of the receivers is ISATM (ionospheric scintillation and TEC monitor) developed by Wuhan University which key component is a OEM628 card produced by the NovAtel company, the other is a Septentrio PolaRx5S receiver. For a signal at the frequency of 1.5 GHz, the S4 value greater than 0.2 indicates the occurrence of amplitude scintillation. We found that for the two receivers the difference of S4 values derived from the 1-Hz <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$C/N_{0}$</tex> measurements of B<inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">lI</inf> signals were close to 0.2, and the difference of S4 values derived from the 1-Hz <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$C/N_{0}$</tex> measurements of B<inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2I</inf> signals were much larger than 0.2 during scintillation activities. Therefore, we recommend using GNSS receivers of the same type when conducting GNSS amplitude scintillation monitoring in a large area.