Automatic Dependent Surveillance-Broadcast (ADS-B) is an economically viable alternative to traditional radar-based surveillance for use in Air Traffic Management (ATM). For implementation of ADS-B system, prior RF coverage design is crucial. A software defined radio (SDR)-based ADS-B measurement system is developed. Calibration of the system, test measurement at few probable sites and preliminary coverage analysis are reported. In mountainous terrains, the 1090 MHz RF coverage of ADS-B system is affected mainly by receiver locations. Measurement of the RF signal for validation of prediction methods to be used for final coverage is essential. © 2021, Springer Nature Singapore Pte Ltd.