Visualizing RFID

jamie found a video on Warren Ellis's blog introducing a new way to visualize RFID fields. The film is by Timo Arnall and Jack Schulze. The subject is introduced in words on the BERG site (a design consultancy); the tech behind it is explored at Touch, a project that experiments with near-field communications. "This image is a photographic mapping of the readable volume of a radio field from an RFID reader. The black component in the image is an RFID reader... The camera has been fixed in its position and the reader photographed. Using a tag connected to an LED we paint in the edges of the readable volume with a long exposure and animate them to show the form."

Comments

New Technique

[cjfs]

Using their technique, we can now profile our cards to provide maximum protection with minimum tinfoil!

Re:New Technique

[noundi]

Using their technique, we can now profile our cards to provide maximum protection with minimum tinfoil!

I have one of those metal card holders which, at first, I was disappointed at since it isolated my RFID keycard at work, because it would be very convenient to just flash the whole card holder. Then I came to my senses and realised that it was a good thing that I always chose when the card was readable and when it was't. It was one of those moments when you just appreciate what you have.

Better link to video

[schlick]

Here is the link to the non-embedded video.

http://vimeo.com/7022707

Simple method for visualizing RFID

[syousef]

1. Pick up RFID chip
2. Look at it. It's an RFID chip! You have just visualized it.
3. ???
4. Profit

The field patterns of loop antennas

[Technician]

The free field pattern near a loop antenna is nothing new. RFID or any other application such as a transmitter for the heairng impaired makes no difference.

A 3D plot of a simple loop antenna can be seen on this page;
http://vk1od.net/antenna/SmallUntunedSquareLoop/
The 3D plot is near the bottom of the page.
It it resembles the magnetic field of a bar magnet or a coil of wire with a current, that is no supprise.

Re:The field patterns of loop antennas

[buchner.johannes]

Does it bother other people too that we lack good methods of visualizing 3D/4D data? like a sensor value dependent on spacetime v(x, t)?

Can anyone hint me to good methods? I know there are some very experimental 3D-displays.

Re:The field patterns of loop antennas

[buchner.johannes]

Electromagnetism is not new, no. Your link shows a field produced by a antenna, which is only a theoretical concept (abstracting away the measuring sensor).
What the pictures in TFA show is the dependency of the field vs. the direction of the measuring device, i.e. a slice of a vector field B(x).

But I do believe that the makers were not interested in the technical aspect, but a design/architectural/artistic aspect.

Re:Matlab

[NixieBunny]

The main reason they did this is to map out the field *interaction* between the RFID tag and the reader, which is not a trivial thing to visualize based on the two data sheets.

Re:... for a given antenna and receiver sensitivit

[Ecyrd]

Yes, but e.g. ISO 14443 RFID passive responses (e.g. the ones used in ICAO-specified RFID passports and paypass cards) very quickly go below ambient background noise, in effect limiting even the theoretical range to 1-2 m for all but most exotic radio-noise free environments.

Passive RFID is only half-radio, really. ;-)

Re:Interesting, but not amazing

[digitig]

The subtlety seems to be that they're not plotting an RF field, they're plotting the volume in which the passive tag will respond to an RF field (of a given strength). It's another level of abstraction. Yes, once somebody has come up with the idea then the implementation looks simple enough, but the idea is quite remarkable.

Re:... for a given antenna and receiver sensitivit

[RiotingPacifist]

but neither does sound, light, your body(ok so using QM is cheating) but background noise quickly makes practical limits, hard limits (you can edge around the limit but if the signal is noisey and the noise is noisey there is not much you can do)