Method and apparatus for blurring effect mitigation in ground-based radar images

A method for mitigating the blurring effect in a ground-based radar image (40) of a scenario (1) including a plurality of targets (2j, 3), said method comprising the steps of:

• prearranging (100) a ground-based radar system (10) including a radar antenna unit (20) and a radar sensor unit (30),
• said radar sensor unit (30) configured to obtain respective range measurements (r) and respective radial velocity measurements (vR) of said targets (2j, 3),
• selecting (110), in said radar sensor unit (30), a Pulse Repetition Frequency (PRF) value such that said radial velocity measurements can be obtained up to a maximum unambiguous velocity (vmax) of said targets (2j, 3);
• selecting (101) a radial velocity threshold (v*), said radial velocity threshold (v*) defining, among said targets (2j, 3):
• a plurality of substantially stationary targets (2j) having radial velocities (vR, j) lower than or equal to said radial velocity threshold (v*);
• at least one fast-moving target (3) having a radial velocity (vR, f) higher than said radial velocity threshold (v*);
• scanning (120) said scenario (1) by said radar system (10), including steps of causing said radar antenna unit (20) to emit transmission signals (22) and of receiving backscattered signals (23) from respective said targets (2j, 3) in response to said transmission signals (22);
• extracting (130) raw data (25) from said backscattered signals (23), said raw data (25) related to said targets (2j, 3) including said substantially stationary targets (2j) and said fast-moving target (3);
• Doppler-processing (140) said raw data (25), obtaining Doppler-processed data (27) containing said radial velocity measurements (vR), in order to discriminate:
• first data (32) that are related to said substantially stationary targets (2j), and
• second data (33) that are related to said fast-moving target (3),
• according to whether said radial velocity measurements (vR) are lower or not lower than said radial velocity threshold (v*), respectively;
• removing (150) said second data (33) from said Doppler-processed data (27), obtaining said first data (32) alone, which are related to said substantially stationary targets (2j);
• forming (160) a radar image (40) of said scenario (1) from said first data (32) said radar image (40) representing only said substantially stationary targets (2j).