The object detection system includes an object sensor and a controller. The controller is configured to compare a sensed range of an object with a range gate based on the azimuth angle of the object. The range gate for each azimuth angle is programmable and is selected to form a contiguous sensing region closely matching the shape of a desired detection zone. The object sensor is switchable between the plurality of sensing fields, wherein a range gate for each sensing field is programmable to form a contiguous sensing region. The object sensor may be a variety of range sensors including radar, ultrasonic, laser or infrared technologies. The range gate and parameters of the sensing field are each programmable through a controller. Further, the controller may automatically vary the range gate or sensing field based on vehicle parameters.