Moving Sensor Tracking using Radio Interferometric Positioning System Measurements

In this work, we study the case of tracking a moving sensor using the radio interferometric positioning system measurements. The system consists of four wireless network nodes and it measures the sum of signal phase differences between two receivers while the other two are transmitting sine waves at close frequencies. With the locations of three sensors known, we can estimate the fourth sensor moving trajectory from a sequence of phase measurements using a nonlinear filter. Two nonlinear filters, a natural gradient Kalman filter and a extended Kalman filter, are investigated and implemented for this moving sensor tracking problem. The performances of them are compared in a computer simulated tracking experiment.