One of the most popular ways to perform navigation is using Inertial Navigation Systems (INS). However, INS solution degrades with time. To circumvent that drift, INS is regularly fused with other sensors or data. The aim of this research is to find means to mitigate the INS drift. Specifically, we explore the possibilities of employing software solutions for INS fusion, instead of traditional hardware aiding. We derive herein analytical solutions to evaluate the aided INS performance. These closed-form bring insight into the effect of the various parameters involved in such fusion. In cases...