Below 900 MHz the target radar cross section increases exponentially[clarification needed], however the increased radar cross section means that there is also much more radar return from undesirable sources, such as cloud cover and rain (cf.
Recent interest has accumulated in developing radars which operate in these low frequencies to help counter the advancement in stealth technology by applying advanced digital signal processing to these bands in order to reduce radar clutter.
If the radar wavelength is roughly twice the size of the target, a half-wave resonance effect can still generate a significant return.
However, low-frequency radar is limited by shortage of unused frequencies, lack of accuracy given the long wavelength, and by the radar's size, making it difficult to transport and making for an easy target.
A long-wave radar may detect a target and roughly locate it, but not identify it, and the location information lacks sufficient accuracy for weapon targeting.