A vehicle pre-impact sensing system is provided that includes an array of
energy signal transmitters mounted on a vehicle for transmitting signals
within multiple transmit zones spaced from the vehicle and an array of
receiver elements mounted on the vehicle for receiving signals reflected
from an object located in one or more multiple receive zones indicative
of the object being in certain one or more zones. A processor processes
the received reflected signals and determines range, location, speed and
direction of the object, determines whether the object is expected to
impact the vehicle as a function of the determined range, location, speed
and direction of the object, and generates an output signal indicative of
a pre-impact event. The system may detect one or more features of a
target object, such as a front end of a vehicle. Additionally, the system
may modulate the transmit beams. Further, the system may perform a
terrain normalization to remove stationary items.