UHF spectrogram shows received signal strength (RSSI) in a 1 MHz wide channel for frequencies between 470 MHz and 900 MHz. The receiver continuously sweeps the band, making approximately 5 signal strength measurements per second.

Dark blue line shows the value of the last measurement. Light blue line shows the maximum observed signal strength (max hold). Red circle shows currently tuned channel. Gray bars show averaged power in 8 MHz channel raster used for TV broadcasts.

MAC (maximum auto correlation) detector detects the presence of a narrow-band transmission in a channel. Gamma is a test statistic calculated from the covariance matrix of baseband signal samples. If gamma value observed in any of the 8 samplings in a 8 MHz channel is above a preset threshold, the channel is marked as occupied.

VHF spectrogram shows received signal strength (RSSI) in a 1 MHz wide channel for frequencies between 40 MHz and 470 MHz. The receiver continuously sweeps the band, making approximately 5 signal strength measurements per second.

Dark blue line shows the value of the last measurement. Light blue line shows the maximum observed signal strength (max hold). Red circle shows currently tuned channel.