Methods of determining whether a jamming signal strength is adequate, comprising receiving a signal, determining first and second noise power levels of the signal in first and second ranges of frequencies, the first range being broader than and encompassing the second range, and calculating a ratio of the second noise power level divided by the first noise power level. Also, methods of determining whether a jamming signal strength is adequate, comprising receiving a signal, determining a phase difference between first and second frequency range phases of the signal, and calculating a statistical mean and/or a standard deviation of the phase difference. Also, systems for determining whether a jamming signal is adequate, computer-readable media for determining whether jamming signal strength is adequate, systems comprising means for transmitting a jamming signal, and systems comprising means for transmitting and receiving waveforms to users in the presence of protective jamming.