ScintPi 4.0: A New GNSS‐Based Low‐Cost, Multi‐Constellation, Multi‐Frequency Ionospheric Scintillation and TEC Monitor for Education, Citizen Science, and Research Initiatives

Abstract ScintPi is a series of alternative ionospheric scintillation and total electron content (TEC) monitors. ScintPi monitors have been built by combining single‐board computers (Raspberry Pi) and commercial off‐the‐shelf (COTS) Global Navigation Satellite System (GNSS) receivers. Their development was motivated by the necessity of low‐cost monitors for use in various research and educational projects. Here, we introduce and present results obtained with the fourth version of ScintPi (ScintPi 4.0). ScintPi 4.0 uses the Septentrio Mosaic‐X5 GNSS receiver, which increases the number of signals, sampling rate, and the carrier‐to‐noise density ratio (C/No) resolution compared to previous ScintPi versions. After initial tests in the lab, we deployed two closely spaced ScintPi 4.0 monitors at the low‐latitude site of Fortaleza, Brazil (3.74°S, 38.58°W, 8°S dip latitude) for field tests. Additionally, one of the ScintPi 4.0 monitors was collocated with a commercial ionospheric monitor (PolaRx5S). The results show that ScintPi 4.0 can provide amplitude scintillation indices (S 4 ) and TEC measurements that are in excellent agreement with those provided by the collocated PolaRx5S. Additionally, we introduce two measurement capabilities that were not available in previous ScintPi versions: First, Mosaic‐X5's multi‐frequency capability allowed estimates of ionospheric TEC using L1 and L5 signals transmitted by geostationary satellites. Second, despite using a lower cost, less stable clock compared to commercial monitors, ScintPi 4.0 was able to produce accurate estimates of phase scintillation indices (). Finally, we present examples of irregularity drift estimates obtained using the spaced‐receiver scintillation technique and measurements made by ScintPi 4.0.