for feasib.. radar.

what kind of sensor or arduino will i use if i’m planning to build a radar that can detect planted chips in id card? the maximum range for the chips to be detected is by 30meter and the location area has a lot of walls that can interfere the signal, like a floor with many room.
is that possible?
i’m newbie. please guide me. thanks.

You know much about radar? The microwave energy to read 30m through walls will damage flesh in the way.

Just there, you have a very bad idea.

The signal will reflect strongly off metal including pieces of metal in the walls (like nails, staples, electric wires) giving a mess of return clutter. How to tell which is which, what and where any of it is? How to tell ID from bank card?

You plan on finding chips in ID cards that are in people's pockets? And without their knowing much less consent? Are you a teenager?

Around you I would want not just a steel card case but a steel suit!

so what do you think the best alternative for chips, that can be located its position or maybe its presence...
ex. a school building floor.. without looking each room you can identify if someone still in the vicinity because they are wearing school id that can be detected.
sorry for my grammar.. tia

Whatever is done can be fooled, accept that the ID is not the person. The hard part will be fool-proofing.

RFID badges and RFID readers in door frames can get most of what you need.

NewbIeMonkey:
what kind of sensor or arduino will i use if i'm planning to build a radar that can detect planted chips in id card?

What is the purpose of this?

I suspect it is at least anti-social and possibly illegal?

...R

See Reply #2

If you just want to detect people PIR is a good technique.

Allan

just for thesis...
originally, i was thinking about putting chips inside an id for security purposes that can use in emergency cases like fire or quake, when they are inside the vicinity, or when at night, to ensure no student are still there, and etc.
but as it's said, it's not feasible.
that's why i'm asking for some tips. i want to learn more. thank you for your advice.

GoForSmoke:
See Reply #2

That does not satisfy my concerns.

...R

Pass cards are common, lots of workplaces, schools and the like already have them.

If it were relativly easy, within the scope of a hobyist, you would expect that if it were possible\viable to put a 'chip' inside a passcard so that you could tell with a single remote device (the OP said 30M distance) how many people were in a building, and where they were, such systems would be readily available.

I dont think they are.

srnet:
I dont think they are.

And I hope they never are created even if future technology makes it possible. That level of monitoring would be a grave intrusion into our personal freedom.

Which is why I wrote Reply #4

...R

Robin2:
And I hope they never are created even if future technology makes it possible. That level of monitoring would be a grave intrusion into our personal freedom.

Which is why I wrote Reply #4

...R

Kind of like CCTV and facial recognition?

Paul

Paul_KD7HB:

Quote from: Robin2 on Today at 05:45 pm

And I hope they never are created even if future technology makes it possible. That level of monitoring would be a grave intrusion into our personal freedom.

Which is why I wrote Reply #4

...R

Kind of like CCTV and facial recognition?

Paul

you mean like Smart TV's, cell phones and PlayStation ?
things that monitor your bio signature, know were you are in the room, and if you are moving or resting ?
That is all here already.

dave-in-nj:
you mean like Smart TV's, cell phones and PlayStation ?
things that monitor your bio signature, know were you are in the room, and if you are moving or resting ?
That is all here already.

There is no obligation to carry one of them.

But now you mention it, maybe I have lived long enough.

...R

dave-in-nj:
Kind of like CCTV and facial recognition?

Paul
you mean like Smart TV’s, cell phones and PlayStation ?
things that monitor your bio signature, know were you are in the room, and if you are moving or resting ?
That is all here already.

This was my initial thought. A wifi network can easily be monitored to determine devices that are within range, thus tracking the presence or absence of the specific device ID and presumably it’s owner. This can be defeated by the user turning off the device or device wifi. It’s not clear whether this meets the original poster’s requirements.

There exist office tracking systems that use a power-controlled wifi device to determine whether or not a badge is in the area and infrared signaling to localize to a particular room. Again this depends upon the persons to actually wear the badge and it’s not a passive system.

A fully passive RFID system at tens of meters is probably well beyond hobbyist level technology, but there are systems that can detect RFID chips from a meter or so and these could be placed at entrances and exits to monitor card holders entering and leaving.

But it works so well for Hollywood.... it MUST be easy to do....

Have you looked into active RFID tags.

Every mobile phone updates it's registration periodically. You could pick that up.

Allan

123Splat:
But it works so well for Hollywood.... it MUST be easy to do....

Can't help myself.