Efficient adaptive filtering for rain clutter suppression
Date of Issue2011
School of Electrical and Electronic Engineering
Doppler radar in GHz band is primarily used for short range detection of moving objects. A major difficulty in this type of radar is the presence of rain clutter under bad weather conditions. It contains returns of both the target and rain clutter. The robustness of detection heavily relies on target echo, and the rain echo. It is pointed out that rain, which can be treated as object in the atmosphere, will cause time spread of radar echo signals, and this will mask or weaken the returns from the nearby targets. This is, usually regarded as a noise, is known as the rain clutter. Radar systems assume the clutter is stationary with its energy concentrated at low frequencies, and the rain clutter environment is dynamic. Thus, a fixed high pass filter is used to filter out the clutter. This approach has major problem, (1) since rain clutter characteristics is dynamic in nature, where rain clutter characteristics (which is the main noise we are dealing) and the target signal is not fixed. So the designed HPF cannot be used for different environmental conditions. HPF in this regard, has not thus far showed appropriate and satisfactory performance due to its fixed bandwidth nature. This can be observed from the simulations performed in MATLAB environment using real radar rain data.
DRNTU::Engineering::Electrical and electronic engineering
Nanyang Technological University