Topside Ionosphere Reconstruction over India
Context: The Indian Institute of Geomagnetism (IIG), under the Department of Science & Technology (DST), has developed the first India-specific method to reconstruct the topside ionosphere by integrating ground-based ionosonde observations with COSMIC radio occultation data.
Key Facts
- Ionosphere: Ionized layer of the upper atmosphere that supports HF radio communication and influences GPS/NavIC signal propagation.
- Accurate electron density profiles (EDP) up to ~1000 km are essential because most Low Earth Orbit (LEO) satellites operate within this altitude range.
- Earlier models assumed a constant topside scale height, reducing the accuracy of electron density estimation over the Indian region.
- The new approach combines:
- Bottomside ionosonde observations, and
- Altitude-varying topside scale height derived from COSMIC radio occultation measurements,
to generate a more realistic topside electron density profile (EDP).
Significance
- Improves regional ionospheric modelling under varying space weather conditions.
- Particularly useful over the geomagnetic equator, where ionospheric dynamics are highly complex.
- Enhances the reliability of satellite operations, communication systems, GPS/NavIC navigation, and space weather prediction.