Bias Compensated Inertial Navigation for Venus Balloon Missions

—In this paper we investigate various strategies forreducing navigation errors for a future Venus Balloon missionequipped with a low-mass MEMS IMU (e.g. STIM300), andfocus on two of these mitigation strategies in detail. First, weproposed to mechanically rotate the IMU while collecting datathereby averaging out the bias contributions and increasingaccuracy. To this end, we experimentally provide proof-ofconcept by rotating a STIM300 IMU about a single-axis andshow that navigation performance for this idealized scenario issubstantially improved. Second, we propose to use on-boardaccelerometer measurements to exploit the projection of thegravity field along the axes of the IMU frame to provide (2 axis)attitude information. To this end, we design a Kalman Filterfor a hovering balloon scenario where the accelerometer measurements are modeled as explicit functions of attitude and areincorporated as direct measurements in the filter and show thatthis strategy leads to improved navigation performance. Theresults given here are part of a longer-term effort to understandand improve navigation performance on a Venus Balloon andshould be considered as first steps toward this goal.