The Indian Regional Navigation Satellite System (IRNSS/NavIC) is fully operational and broadcasting radio signals at L5 (1176.45 MHz) and S-band (2492.028 MHz). When these signals pass through the ionosphere, carrier phase delay, which depends on Total Electron Content (TEC), causes error in positioning. Corrections are applied in the augmented navigation system to minimize the position error due to TEC; however, 100% removal of error is practically impossible. Thus, a study has been carried out to understand the role of ionospheric determinants, such as TEC and scintillation S4, on the accuracy of augmented navigation over low latitude region using a dual-frequency NAVigation with Indian Constellation (NavIC) receiver installed at BITS-Pilani K.K. Birla Goa Campus (Geog. Lat. $15.39°$N, Geog. Long. $73.87°$E). Data collected using the Indian Space Research Organization (ISROs) NavIC receiver (make DataPattern) during the low solar period between March 2019 to December 2019 is utilized for this study. The important findings of the study are as follows: (a) Mean position error was in the range of 2–4 m. (b) Diurnal variation of the position error indicated a maximum at afternoon hours, coinciding with the time of maximum TEC over the EIA crest region. (c) Mean position error in afternoon hours indicated a linear relation with mean TEC, in a scatter-plot analysis. (d) Statistically, the position error during the scintillation nights was found to be similar to non-scintillation nights, indicating that the post-sunset equatorial density depletions during low solar do not significantly impact navigation accuracy. Absolute position error during the active phase of a moderate geomagnetic storm of 14 May 2019 was found to be significantly higher compared to a quiet period, which also depends on the mode of operation of the augmented navigation system. It was found that a hybrid NavIC (Dual) + GPS (SBAS) augmented navigation was more accurate than NavIC with dual- ionospheric corrections or NavIC with grid corrections, alone. Besides, the dynamic behavior of the ionosphere, i.e., diurnal, monthly, and seasonal variations of ionospheric TEC, have also been studied using the iono-delay values derived from the NavIC receiver.

印度区域导航卫星系统 (IRNSS/NavIC) 已全面运行并在 L5 (1176.45 MHz) 和 S 波段 (2492.028 MHz) 广播无线电信号。当这些信号通过电离层时，取决于总电子含量 (TEC) 的载波相位延迟会导致定位错误。在增强导航系统中应用修正以最小化由 TEC 引起的位置误差；然而，100% 消除错误实际上是不可能的。因此，已经开展了一项研究，以了解电离层决定因素（例如 TEC 和闪烁 S4）对使用安装在 BITS 的印度星座 (NavIC) 接收器的双频导航在低纬度地区增强导航准确性的作用。 Pilani KK Birla Goa 校区（Geog. Lat.$15.39°$N，乔格。长。$73.87°$E)。本研究利用了在 2019 年 3 月至 2019 年 12 月的低太阳时期使用印度空间研究组织 (ISRO) 的 NavIC 接收器（制作 DataPattern）收集的数据。研究的重要发现如下： (a) 平均位置误差在 2-4 m 范围内。(b) 位置误差的昼夜变化在下午时间显示最大值，与 EIA 波峰区域上的最大 TEC 时间一致。(c) 在散点图分析中，下午的平均位置误差表明与平均 TEC 呈线性关系。(d) 从统计上看，闪烁夜的位置误差与非闪烁夜的位置误差相似，表明低太阳期间的日落后赤道密度损耗不会显着影响导航精度。发现 2019 年 5 月 14 日中等地磁暴活动阶段的绝对位置误差与静默期相比要高得多，这也取决于增强导航系统的运行模式。发现混合 NavIC (Dual) + GPS (SBAS) 增强导航比单独使用双电离层校正的 NavIC 或带网格校正的 NavIC 更准确。此外，电离层的动态行为，即电离层 TEC 的日变化、月变化和季节变化，也已使用从 NavIC 接收器得出的电离延迟值进行了研究。发现混合 NavIC (Dual) + GPS (SBAS) 增强导航比单独使用双电离层校正的 NavIC 或带网格校正的 NavIC 更准确。此外，电离层的动态行为，即电离层 TEC 的日变化、月变化和季节变化，也已使用从 NavIC 接收器得出的电离延迟值进行了研究。发现混合 NavIC (Dual) + GPS (SBAS) 增强导航比单独使用双电离层校正的 NavIC 或带网格校正的 NavIC 更准确。此外，电离层的动态行为，即电离层 TEC 的日变化、月变化和季节变化，也已使用从 NavIC 接收器得出的电离延迟值进行了研究。