Measuring Signal Environment in the Aircraft Surveillance Frequency by Flight Experiments

Currently, many radio systems are used for air traffic management (ATM). Secondary surveillance radar (SSR) and associated systems that operate at frequencies 1030/1090 MHz are one of the most important components of ATM. These systems exchange pulse signals between a transponder and an interrogator using random-access methods for channel sharing. Recently, using these 1030/1090 MHz systems in ATM are expected to increase as air traffic increases in density. For efficient and effective 1030/1090 MHz radio operations, the signal environment in this frequency band must be understood and managed. This study aims to report measurements of the 1030/1090 MHz signal environment, recorded during flights over Japan. The relation between the number of aircraft or terminals and the signal environment with multipath propagation and/or interference is discussed.