ive ordered a gjd xl opal. My driveway is approx 10m deep. The idea of the detector is to alert me inside, using the gjd controller for activity on the driveway. Would I be best to mount the detector above the windows on ground floor or put them on the ground near the pavement facing the house. My thinking is that I would have less false alarms, (though maybe not from local cats). Anybody have any experience installing these? thanks