Visualization of global BILSAT-1 VHF frequency usage

BILSAT-1, a 130 kg enhanced micro satellite, is Turkey\´s first Low Earth Orbit Earth observation satellite. The satellite project was started in August 2001 at Surrey Satellite Technologies Limited (SSTL)\´s facilities in Guildford, UK and BILSAT-1 was launched successfully from the Plesetsk Cosmodrome, Russia on 27 September 2003. The BILSAT-1 communications subsystem is composed of VHF/UHF (amateur space band) and S-Band (commercial space band). The VHF receivers are always "ON" in orbit and can collect received signal strength data. This data can be sent down to the ground station. Therefore we can establish a map of VHF frequency usage of BILSAT-1 operation frequencies for the entire world. In this paper, in-orbit frequency usage or interference data for the BILSAT-1 VHF frequency band is presented.