hardware. Then, we consider the noise at the receiver. Since our proposed electric sense-based scheme can be applied to different underwater robots or vehicles, the noise we focused on refers to the environmental noise at the receiver, excluding the electrical noise from robotic components, such as propellers. When working indoors, the noise in different rooms varies greatly because the environmental noise mainly comes Table 3. The experimental results of Experiment 3. Method Emitter Electric + IMU + Dynamic Archi. 1 Archi. 2 Electric + IMU IMU + Dynamic Archi. 3 Archi. 1 Archi. 2 Archi. 3 Archi. 1 Archi. 2 Archi. 3 errpos (cm) errori 16.6 15.5 15.3 35.5 132 44.7 114.4 113.7 135 14.8∘ 10∘ 10.3∘ 14.3∘ 17.9∘ 7.2∘ 6.8∘ 10.3∘ 9.3∘ Archi. Architecture; errpos (respectively, errori) is the average position error (respectively, orientation error) under the three localization