PS Radar attenuation is part and parcel of the system. If a sufficiently strong beam is emitted it could pass through all weather giving no returns. Not much good for WX spotting.
The signal needs to be of just the right strength to be partially reflected thus showing the WX. The snag is the weaker beam also suffers attenuation.
Can you amplify that remark, preferably with a technical reference? I find the physics, as worded, difficult to relate to.