GPSdome is a small-sized (tailored for class 1-3 drones), retrofit module (compatible with any GNSS based receivers) that provides protection against GPS jamming, ensuring continuity of autonomous navigation and operation under GPS challenged conditions. GPSdome protects GPS L1, GPS L2 and Glonass and at its minimal size weight and power there is no other solution that offers such protection is as small, light, affordable or as easily installed as GPSdome.