Multimodal Sensor Networks

We first looked at how feedback from cameras can be used to calibrate the magnetometers . In our model the magnetic field signal strength follows a power law with unknown exponent beta. The goal of the calibration process is to estimate the value of beta. The process works as follows: Motes use trilateration to estimate the position of the target. This information is then passed to the cameras which locate the actual position of the target. We then solve a non-linear optimization problem to minimize the distance between the target's actual location and the location estimated using the magnetometer measurements. Our simulation results show that the estimation process converges in a small number of iterations.