Inertial error modeling is at the heart of all inertial integration filters. The NSI&KF Toolbox provides a stand-alone inertial state-space error model. The user can specify arbitrary combinations of gyro and accel bias errors along with initial position, velocity and attitude errors. The model can then be executed to determine how these combination of ‘input’ errors propagate into position/velocity/attitude errors over time. The example below shows the error propagation for the case of an INS (initially level and pointed north) with a 100 micro-g body x-axis accel bias and a 0.01 deg/hr body y-axis gyro bias:
