RELATIVE NAVIGATION USING ARTIFICIAL MAGNETIC FIELDS

We show that magnetometer sensing of artificially generated magnetic fields may be used for relative navigation. Two artificial field emitters are mounted in a host spacecraft, each excited with a unique AC code. The resulting magnetic fields determine the 6-axis pose of a co-orbiting spacecraft. If the emitters are comparable in size to existing magnetic torquers, the co-orbiter needs only a cubesat- class IMU to determine its relative state with sufficient accuracy and bandwidth for hovering or docking. The artificial fields can be acquired at a range of up to 10 meters, a safe distance for handoff from a GPS-based absolute navigation system. The proposed system utilizes equipment already available on many missions and, unlike optical sensing systems, has no restrictions on relative position, lighting, or fields of view. We present a theoretical development and results of a subscale lab demonstration with a range of 2 meters.