# Validating Ionospheric Scintillation Indices Extracted from 30s-Sampling-Interval GNSS Geodetic Receivers with Long-Term Ground and In-Situ Observations in High-Latitude Regions

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## Abstract

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## 1. Introduction

## 2. Methods to Estimating the Scintillation Indices

#### 2.1. Phase Scintillation Index (${\sigma}_{\varphi}$) from 50 Hz ISMR Observations

#### 2.2. Rate of Change of Density Index (RODI) Estimated from the Electric Field Instrument of Swarm Satellites

#### 2.3. Rate of TEC Index (ROTI) Estimated from 30s-Sampling-Interval GNSS Observations

#### 2.4. The ${\sigma}_{\varnothing f,30s}$ Index Based on Continuous Wavelet Transform

## 3. Introduction to the Adopted Data

## 4. Performance of the 30s-Sampling-Interval Scintillation Indices in Monitoring Scintillations

#### 4.1. Analysis on the Accuracy of the 30s-Sampling-Interval Scintillation Indices in the Time Aspect

#### 4.2. Analysis on the Accuracy of the 30s-Sampling-Interval Scintillation Indices in the Space Aspect

## 5. Conclusions

## Author Contributions

## Funding

## Data Availability Statement

## Acknowledgments

## Conflicts of Interest

## References

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**Figure 2.**Scintillation detection performance of the ${\sigma}_{\varphi}$ (

**a**), ${\sigma}_{\varnothing f,30s}$ (

**b**) and ROTI (

**c**) indices on the observation arc of PRN 32 at station arcc on the 111th day of year 2020. The “Scint. Mag.” in the y label stands for the scintillation magnitude.

**Figure 3.**Daily scintillation occurrence rates in the year 2020 at stations arcc (

**a**) and chuc (

**b**). The rate differences between ROTI and ${\sigma}_{\varphi}$ at stations arcc and chuc are shown in panels (

**c**) and (

**e**) respectively, while those between ${\sigma}_{\varphi f,30s}$ and ${\sigma}_{\varphi}$ at stations arcc and chuc are displayed in panels (

**d**) and (

**f**).

**Figure 4.**Correlation between the daily scintillation occurrence rate and the Ap index. The “corr.” denotes correlation.

**Figure 6.**Local time and seasonal dependency analysis of the ionospheric scintillation occurrence rate.

**Figure 8.**Scintillation monitoring performance of the grid model constructed with the 30s-sampling-interval scintillation indices along an observation arc of Swarm A. (

**a**) Observation arc of Swarm A in the research region, with timestamps, (

**b**,

**c**) the scintillation grid model based on the ground geodetic GNSS observations during the period of the observation arc of Swarm A, (

**d**) the in situ plasma density from Swarm A, (

**e**) the in situ RODI from Swarm A, (

**f**) the variation of ROTI along the observation arc of Swarm A and (

**g**) the variation of the ${\sigma}_{\varnothing f,30s}$ index along the observation arc of Swarm A. The ionosphere region flags 1, 2 and 3 represent the middle latitudes, the auroral oval and the polar cap region, respectively.

**Figure 9.**Statistical analysis on the scintillation monitoring performance of Swarm A (Panels (

**a**,

**c**)) and the ground GNSS geodetic receivers (Panels (

**b**,

**d**)) in the whole year of 2020.

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**MDPI and ACS Style**

Zhao, D.; Wang, Q.; Li, W.; Shi, S.; Quan, Y.; Hancock, C.M.; Roberts, G.W.; Zhang, K.; Chen, Y.; Liu, X.;
et al. Validating Ionospheric Scintillation Indices Extracted from 30s-Sampling-Interval GNSS Geodetic Receivers with Long-Term Ground and In-Situ Observations in High-Latitude Regions. *Remote Sens.* **2022**, *14*, 4255.
https://doi.org/10.3390/rs14174255

**AMA Style**

Zhao D, Wang Q, Li W, Shi S, Quan Y, Hancock CM, Roberts GW, Zhang K, Chen Y, Liu X,
et al. Validating Ionospheric Scintillation Indices Extracted from 30s-Sampling-Interval GNSS Geodetic Receivers with Long-Term Ground and In-Situ Observations in High-Latitude Regions. *Remote Sensing*. 2022; 14(17):4255.
https://doi.org/10.3390/rs14174255

**Chicago/Turabian Style**

Zhao, Dongsheng, Qianxin Wang, Wang Li, Shuangshuang Shi, Yiming Quan, Craig M. Hancock, Gethin Wyn Roberts, Kefei Zhang, Yu Chen, Xin Liu,
and et al. 2022. "Validating Ionospheric Scintillation Indices Extracted from 30s-Sampling-Interval GNSS Geodetic Receivers with Long-Term Ground and In-Situ Observations in High-Latitude Regions" *Remote Sensing* 14, no. 17: 4255.
https://doi.org/10.3390/rs14174255