PIR Sensor for Staircase Lighting

[secware3]

 

I’m looking for a PIR sensor that can detect movement both from the bottom and the top of a staircase. Our current sensor is positioned on the wall above the door at the bottom of the staircase, but it only detects movement when someone is about four steps from the bottom. This is creating a safety risk, as the lights aren’t activating until a person walking down is already quite close to the bottom. The staircase is approximately 9 metres long. I have images I can share — please let me know an email address where I can send them. I was looking at the following item and was wondering if it would work for my requirements, or if you could recommend a product that would be more suitable for my situation. Thank you! https://www.securitywarehouse.co.uk/catalog/intruder-alarm-equipment-c-36/movement-detectors-c-36_116/all-c-36_116_37/optex-cx702-21m-wide-or-45m-long-pir-p-157.html