NEW DELHI — An official with India’s space agency says the country’s homegrown satellite navigation system is on track to become fully operational for Indian users in July/August 2015. With the development of the Indian Regional Navigation Satellite System (IRNSS), an indigenous GPS system “is on the anvil,” says K. Sivan, director of the Indian Space Research Organization’s (ISRO) Liquid Propulsion Systems Center. India currently uses other countries’ satellite services for navigation applications requiring GPS.