The Indian Spa ce Research Organisation (ISRO) is in the process of deploying the Indian Regional Navigation System (IRNSS), a dual frequency service system. Another contribution by ISRO in the area of Navigation system is GPS Aided GEO Augmented Navigation (GAGAN)

Indian Regional Navigation Satellites System (IRNSS) is the world’s fi rst regional navigation system with its footprint primarily over the Indian subcontinent. The system is expected to have seven satellites in all, with three satellites in GEO stationary and four in GEO synchronous orbits (Kibe & Gowrishankar 2008). IRNSS is dual use and supports two frequencies on either service of operation.

Amongst GNSS receiver design criteria such as accuracy, sensitivity, channels etc., the Time To First Fix (TTFF) is an important criterion, which defines how fast a navigation solution is available to the user since receiver power on.