Cumulative Distribution Function Analysis on Radio Frequency Spectrum Survey for Solar Monitoring Applications

Solar activity has been observed since ancient times to anticipate its direct impact on life on earth. One of the instruments developed to monitor solar activity is the Callisto spectrometer developed by ETH Zurich, Switzerland. This instrument is spread in many countries, collaborating in the e-Callisto network. To build this system, it is necessary to conduct a radio frequency spectrum survey to see whether the spectrum conditions in a certain place allow Callisto to be installed or not. In this study, a radio frequency spectrum survey was conducted at Telkom University, Bandung, Indonesia. The RF signal strength in several frequency bands protected for radio astronomy observations is recorded. The obtained data was analyzed by using Cumulative Distribution Function (CDF) analysis to determine whether solar activity monitoring can be carried out at this location, within the Callisto frequency range. Observational results show that the signal level in all investigated frequency bands is relatively low, well below − 85 dBm for all bands, and with 80% samples are lower than − 100 dBm. Therefore, the observational sites are suitable for solar activity monitoring.