Hi all.
Am working on project that requires an indoor/outdoor positioning system, with an accuracy of 30-50cm. The system includes potentially using an Ultrasonic signal to mesure TOF in conjunction with an RF signal.

The sensor:
the "zone of sensitivity" should be about a 2-4m region. BUT... that zone needs to be bw 20-60 meters away. So I need a signal receiver (sensor) system that is sensitive within a 2-4m region, but able to pick up that sensitivity from a distance.

If this is practically possible, obviously there will be a lot more involved in band filtering and boosting the signal source... Im aware of that, but Im struggling to find a sensor that meets my requirements, and thought someone might know of such a sensor/sensing system.

Or is such a sensor not feasible or simply doesn't exist

 

Hello,
What you need pls tell step not clear to me!
20-60 meters away.
The ultrasonic work only ~10-15 feet! (my view)

 

Hello,
What you need pls tell step not clear to me!
20-60 meters away.
The ultrasonic work only ~10-15 feet! (my view)

I vaguely remember that the old Polaroid cameras could focus out to about 50 feet (15 meters). This required a large transducer and a 200 volt pulse.

A large transducer gains in 2 ways. First, a bigger signal is transmitted and received. Second, the transducer can be focused. In your case, you would want to focus at around 40 meters +/-20 meters. I don't know how practical this is.