Satellite navigation systems are based on the Global Positioning System (GPS) and other national and multinational satellite initiatives (for example, Glonass and Galileo) with applications in consumer and commercial markets. Satellite navigation systems are embedded in a vehicle, available as a portable unit (personal navigation device (PND)) or offered as an application in cellular phones, with an internal or external GPS antenna, and can be complemented with cellular tower or Wi-Fi-enabled triangulation (assisted GPS).