Navigation is an indispensable part of everyday human life. In recent times, satellite based navigation system has proven to be indispensable in various navigation and scientific applications . The backbone of satellite based navigation systems is very precise and highly stable atomic clocks. Satellite-based and ground-based clocks formulate the complete operability of a navigation system. The satellite-based clocks fall under the category of portable and space qualified atomic frequency standards. For the applications that demand to address the issues of performance, portability, reliability, cost, weight, volume and power consumption, the Rubidium Atomic Frequency Standards (RAFS) are advantageous over other kinds of clocks [2, 3]. These characteristics makes it is a suitable candidate for portable and onboard navigation payload applications such as Global Navigation Satellite Systems (GNSS). At the Space Applications Centre, we are indigenously designing and developing the RAFS for Navigation with Indian Constellation (NavIC) [previously known as Indian Regional Navigation Satellite System (IRNSS)]. © 2019 URSI. All rights reserved.