A method for electromagnetic navigation registration is provided. The method includes storing, in a memory, a mapping that associates electromagnetic field-based signal values with corresponding locations within a three-dimensional model of a luminal network. An ultrasound signal is received from an ultrasound probe. Based on the ultrasound signal, an ultrasound-based location of a target in a patient relative to the three-dimensional model is determined. At least a portion of the mapping is updated based on the ultrasound-based location of the target.
