Dr. Rajat Acharya is a Senior Scientist at the Space Applications Centre, a key unit of the Indian Space Research Organisation (ISRO). With over two decades of involvement in India's satellite navigation programs—GAGAN and NavIC—he has significant contributions in ionospheric modelling and space weather research. Dr. Acharya serves as Course Director for GNSS and SATCOM at the UN-affiliated Centre for Space Science and Technology Education in Asia and the Pacific (CSSTEAP). He has also been a Visiting Professor at Gujarat University, where he taught postgraduate courses in Geo-informatics and Satellite Navigation. Dr. Rajat Acharya regularly teaches Space Weather at the postgraduate level and has written extensively, authoring other popular books on the subject. He also represented India as Co-Chair of Working Group-C during the sessions of the International Committee on Global Navigation Satellite Systems (ICG).