> Sounds almost perfect to what I need, except for one thing. They state,
> "As the microwave radiation penetrates many materials, such as plastics
> and ceramics which are opaque to light, the sensor modules can for many
> applications be located hidden from view. ".  This is great for human
> presence detection in automatic door opener applications, but I have no
> way of telling what kind materials will come in front of the sensor
> system. Have you tested it with many objects and surfaces? What kind of
> results do you get? What are you using it for?
>
> Thanks.
>
> Sebastian
>
Most plastics and cloth materials have little or no effect on RF, There fore
it will only detect objects of mass like humans, animals, walls, vehicles
and other such items. Example if you have a robot and would like to have a
detector that will tell the controller to turn or avoid an object, this
would be a great item for steering and avoidance, however the more complex
the robot the more sensors needed to determine distance and depth.
I have used it for motion control and the detector will pick up on most
objects. The larger and closer the object, the stronger the return. By
approximating the speed and  direction of the device that is carrying the
sensor, it is possible to determine if an object that is near, is standing
still or moving in relation to the sensor. A moving vehicle can then
determine if it is nearing a wall or tree, or if the object is passing it
by, or determine the rate of closure.

Gordon Varney