Yes, there are four different types of ADS-B ground stations: surface, low altitude, medium altitude, and high altitude. The FAA’s Aeronautical Information Manual, Table 7-1-2, helps compare each station type (Last updated: 4/4/14). The station type varies based on the ground station coverage where you are flying. Learn more information about ADS-B station types and how they interact with your Stratus portable receiver.