Anomalous GNSS Signal Strength Fluctuations during the Amphan Super Cyclone in Eastern India on May 20, 2020

Part of West Bengal, an eastern state of India, was severely affected by a super cyclone Amphan (or Umpun ) on May 20, 2020, during 14:30 to 11:00 h IST with a wind speed of 155–160 km/hr and heavy rainfall. During the most intense event, Global Navigation Satellite System (GNSS) data were collected using a compact GNSS module from a location situated extremely close to the cyclone eye path. Severe fluctuation of satellite signal strength for GPS, Galileo, and Beidou signals was observed during the time in the proximity of the cyclone eye. The signal strength fluctuations caused loss of lock for the signals at the receiver resulting in a low number of used satellites and degraded position solution quality. This manuscript presents the findings which were not reported earlier. The results would be useful for understanding the effects of such events, especially for the disaster management efforts during such events in the cases where GNSS is used.