Ever heard of the TZCAM? - Page 1
Forum section: electronics / general

author: Ben321
author_rank: Frequent Contributor
timestamp: December 19, 2017, 05:27:31 am
content: This is a terahertz wave imager. Its frame size is 320x240, and frame rate is 25fps. It detects wavelengths that are longer than those used by standard thermal imagers, but shorter wavelength than used in most microwave systems. This camera works in that band known as the terahertz band or millimeter-wave band. And yes it is a camera, generating 2d images, not a simple radio tuner with an antenna (which would just allow you record a time-domain signal and carry no 2d data at all unless scanned across a target). According to its specs, it works in the band between 400GHz (0.75mm) and 3THz (0.1mm). Keep in mind, that the shortest wavelength it can detect is 0.1mm which is 100um, and that 100um is still still 10 times longer in wavelength than the center of the band that most thermal imagers operate in. Most thermal imagers work between 8um and 12um (sometimes up to 14um), with 10um at or near the middle of their sensitivity band. But this camera's shortest wavelength is 100um.So it's interesting to note that the technology it uses is the microbolometer focal plain array, the same technology used in standard thermal imagers. So either the material used in the microbolometer is not standard vanadium oxide (or its alternative amorphous silicon), or the camera has some sort of special filter material that keeps standard LWIR from reaching the sensor, or it has some kind of wavelength conversion material (fluorescent material) to convert the ultra-longwave IR to LWIR. However it works though, it is very expensive. At the price $74,149 it costs more than FLIR's most expensive handheld thermal imager, the T1K. And that's just for the imager itself. Unlike thermal imagers, the TZCAM doesn't come with a lens. The lens must be purchased separately, and costs $11,399. I have no idea what the lens is made out of, but at that price it must be a very rare material.Link to the company's home pagehttps://www.terahertzstore.com/Link to TZCAM product pagehttps://www.terahertzstore.com/store/products/terahertz-cameras/terahertz-camera-for-thz-imaging-cea-leti-tzcam.htmLink to product page for lens for TZCAMhttps://www.terahertzstore.com/store/products/terahertz-cameras/terahertz-camera-lens-attachment-for-tzcam.htmI have no idea what the actual applications are for such a device. What I do know though is that blackbody radiation is not strong at these very long wavelengths. Maybe there's some kind of emitter that you would have to purchase that would emit a signal at these wavelengths, to illuminate the object to be observed, in much the same way that the cheaper nightvision scopes (gen1 scopes) require a NIR illuminator for actually seeing in the dark. If so, then I would like to know what could be revealed about an object by illuminating it with millimeterwave/terahertz radiation. Does it allow one to see defects in the surfaces of objects that would otherwise not be visible, like analyzing an aircraft body for normally invisible damage/cracks that could lead to failure in flight?It has a proprietary power connector, but control signals and video output are over a standard USB3 port.Picture of device front, with lens.Picture of device rear.

author: Ultrapurple
author_rank: Super Contributor
timestamp: December 19, 2017, 08:51:43 am
content: That's averyinteresting find. Thanks for bringing it up.I can't really guess about the sensor material but I believe there are some remarkably common materials that can act as lenses in that frequency range. I'm thinking about dielectric materials, plastics, waxes - that sort of thing. I suspect the expense is partly to offset the R&D effort necessary to make the things work. $11,000 doesn't buy much research time. Likewise the cost of the sensor.My expectation is that there will be an increasing use of THz imaging systems for surveillance and suchlike. We've already seen THz-band scanners at airports looking straight through passengers' clothes in search of weapons or contraband; it's not much of an extension to imagine the technology being deployed elsewhere. Of course, THz systems have far wider uses (THz spectral analysis is a fascinating field) but animagingTHz sensor really appeals to me. I like seeing the world in ways different from that perceived by our eyes - hence having imaging gear from LWIR to X-Ray - and I await with interest to hear Fraser saying he has found a bargain THz imaging camera on eBay. (Probably not before 2019).

author: Ultrapurple
author_rank: Super Contributor
timestamp: December 19, 2017, 09:57:56 am
content: Very few details seem to be around on this camera, and even fewer sample images, thoughI did find some others on Twitterthat include a sample image (on a screen) and a description of the device as a "real time camera based on antenna-coupled mocrobolometer 320x240px imager". Elsewhere there are hints about "synchronising with the laser" so it may be that Ben321's guess about 'an illuminator' is correct.There is alsoa page in Frenchthat includes some more discussion and a sample image that appears to be a key seen through a credit card.Perhaps they need someone to take one out in the field and make some pretty images for their promotional material. I could do that...

author: Fraser
author_rank: Super Contributor
timestamp: December 19, 2017, 11:42:43 am
content: The Terrahertz imaging Walabot seems to be an affordable scanning type 'imager' that appears to work quite well when imaging walls etc. The Terrahertz imaging market is still relatively embryonic but hopefully we will see it grow in the same way as thermal imaging.http://terasense.com/news/3d-x-ray-vision-vs-2d-terahertz-imaging-technology/The Walabot is a cheap way to experiment with such technology, a bit like the Seek camera offers for thermal imaging.It offers both the RAW image data and the interpreted (software based target recognition) so you get to see the raw image which is VERY important. It would be less interesting if it tried to show everything it sees as a piece of pipe or a nail !Fraser

author: Fraser
author_rank: Super Contributor
timestamp: December 19, 2017, 01:14:39 pm
content: Walabot seminar.......http://youtu.be/X7lwxOMB6_YFraser

author: Fraser
author_rank: Super Contributor
timestamp: December 19, 2017, 01:18:25 pm
content: And a look at it by Big Clive !https://youtu.be/6fJEm7X_ZuQFraser

author: Fraser
author_rank: Super Contributor
timestamp: December 19, 2017, 01:20:34 pm
content: Mjlorton aSo had a look at it...https://youtu.be/k_32oZrIzY8At $100 for the basic model, it looks a good introduction to such technologyFraser

author: Fraser
author_rank: Super Contributor
timestamp: December 19, 2017, 01:40:54 pm
content: A bit more about Walabot here.....http://cr4.globalspec.com/thread/112828/Walabot-3D-Imaging-SensorI note that they vary the number of antennas depending upon the model you buy. The Pro version has the full compliment of antennas but I believe that costs around $600This Walabot may not be as refined as I had hoped. Early days for this technology, as I said. I am not even convinced that it is a true Terrahertz radar. The Antennas look more like GHz dipoles to me. The old 10Ghz radar technology re thought ?FraserFraser

author: Fraser
author_rank: Super Contributor
timestamp: December 19, 2017, 01:51:40 pm
content: Sorry guys, please ignore my posts on the Walabot.... it is NOT a Terrahertz imagerI feel sure that I read claims that it used the Terrahertz spectrum, but thinking about that for a minute, it's materials penetration was too good for the level of output power.I was correct in my thoughts of it possibly being a revisited GHz radar design. I just found the tech spec. It uses approx 3-10GHz in the USA and 6-8GHz in CE approval countries. I am not so impressed with it nowhttps://fccid.io/2AHIS-VMAKER/User-Manual/Manual-2954449Again, apologies for this unintentional misdirectionFraser

author: Fraser
author_rank: Super Contributor
timestamp: December 19, 2017, 02:26:14 pm
content: An interesting article on the sensor pixel technology used in Terrahertz imaginghttp://rsta.royalsocietypublishing.org/content/372/2012/20130111Fraser

author: Spirit532
author_rank: Frequent Contributor
timestamp: December 19, 2017, 05:28:08 pm
content: A really quick way of explaining terahertz imaging is that the sensor is indeed a regular microbolometer, however, instead of absorbing the LWIR photons directly and converting them into heat, each pixel has what essentially is a wideband dipole antenna(wideband is a relative term, it's just not tuned) that is connected directly across a resistor, effectively shorting it.So when the terhahertz frequency image is focused onto the device, the anntennas receive it, and because they're shorted, they heat the pixel up according to the signal strength.It's a very clever way of indirect conversion, sort of like X-ray cameras work - by converting x-ray photons into light through a phosphor.In terms of optics, long polymers like PVD and POM work well, but some specialised blends exist. It appears that the TZCAM lens uses something completely different, for the enormous price tag. Perhaps a specially coated silicon.Illumination via THz sources is done to increase signal levels, again, same as x-rays - you could image someone with ambient scattering if you're lucky, but if you haven an x-ray tube shining at a few thousand times the background level through them, it's much easier to obtain a meaningful signal.This, in theory, could also be done with any radio frequency, but when you start talking about mm-wave portions of the spectrum, you can imagine how big an image sensor would becomeHere's an example of a video captured by one such camera:

author: Ben321
author_rank: Frequent Contributor
timestamp: December 19, 2017, 07:11:50 pm
content: Quote from: Fraser on December 19, 2017, 01:40:54 pmEven so, you are still using radio waves to make an image. That's quite impressive. And for only $600, that's VERY impressive.

author: Bud
author_rank: Super Contributor
timestamp: December 20, 2017, 01:18:26 am
content: I like it, and also agree the price is good. But gosh, they could chose a better name for the product. It does not ring any bells.

author: Spirit532
author_rank: Frequent Contributor
timestamp: December 20, 2017, 01:37:02 am
content: It'll get cheaper if someone actually uses this tech for anything.Right now it's very much in the "optical stand and safety glasses" region of the market.Look at thermal - the first, analogue, ~100-line AGEMA scanner units were insanely expensive, now you can have 320x240 for under $1000.

author: Bud
author_rank: Super Contributor
timestamp: December 20, 2017, 01:50:56 am
content: My comment was about Walabot.

author: Fraser
author_rank: Super Contributor
timestamp: December 20, 2017, 11:28:48 am
content: The Walabot DIY is on offer in thecUK at the moment. £89https://walabot.com/diyI think the DIY model contains the full set of antennas, but buyers would want to confirm this before buying.The Developer model has the advanced software tools, presumably an SDK.Looking at the 'not compatible with' list I was surprised to see a lot of phones, including the very common Moto series. Weird.Fraser

author: Fraser
author_rank: Super Contributor
timestamp: December 20, 2017, 11:33:44 am
content: The DIY version contains 15 Antennas, the same as the Maker Developer version.https://bigbruin.com/content/walabot-diy_1The Walabot PRO is the best in the range as it offers 3D imaging capabilities and short range imaging.Fraser

author: Ultrapurple
author_rank: Super Contributor
timestamp: December 20, 2017, 01:41:58 pm
content: I understand it's also on offer at $74.90 if you happen to live in the USA.Also, "Walabot is shipped from the United States. The price includes shipment and insurance. It does NOT include any customs fees or VAT."In the UK that means you can expect to pay £89.90 + 20% + £10 clearance fee = £117.88 =~ US$159. That's more than double the US price - ouch!It's still a toy that didn't exist a year or two ago, but as usual Brits (and most other Europeans) get hammered on price.

author: Bud
author_rank: Super Contributor
timestamp: December 20, 2017, 05:37:08 pm
content: Quote from: Fraser on December 20, 2017, 11:33:44 amIf this is the case then the difference should only be in software...

author: Bud
author_rank: Super Contributor
timestamp: December 20, 2017, 05:43:04 pm
content: Quote from: Ultrapurple on December 20, 2017, 01:41:58 pmCan you import it if it is the US model which has a different frequency range (3.3-10.3GHz vs 6.3-83.GHz ) ? If they use chirp waveform across the specified frequency range the US model should have better spatial resolution than the EU one.

author: mikeselectricstuff
author_rank: Super Contributor
timestamp: December 20, 2017, 05:49:24 pm
content: I was sent one of the same Walabot units that Clive got last year, but couldn't get the USB3 to work reliably enough to test. They just asked for the unit back and promised to send one of the consumer ones so watch this space. My guess is it will have fewer antennas, maybe a smaller chip package with fewer channels.Amazon reviews are remarkably polarised - some swear by it, others say it's useless, though the former often mention the need to go through the calibration routine and RTFM.Apparently the DIY is just a spin-off from the primary intended application which is medical imaging, and they'd had some very promising results for early breast cancer detetion, but this takes a while to develop and get approved, so they were exploring other markets in the meantime.

author: Bud
author_rank: Super Contributor
timestamp: December 20, 2017, 06:26:27 pm
content: Quote from: Ultrapurple on December 20, 2017, 01:41:58 pmDoes not seem to be the case. I tried putting one in a shopping card and going to Checkout it added $20 shipping fee to Canada.

author: Ultrapurple
author_rank: Super Contributor
timestamp: December 22, 2017, 08:27:36 am
content: Quote from: Bud on December 20, 2017, 06:26:27 pmI was quoting directly from the Walabot websiteas displayed to me in the UK. Screenshot below; I quoted the last couple of lines.And no, I wasn't planning to buy three of them. I've just visited that page three times via the Buy button. Hopefully it won't mess up their stock control system...

author: Bud
author_rank: Super Contributor
timestamp: December 23, 2017, 12:44:38 am
content: Yes i know. It is when you enter your address in checkout screen it adds shipping charge.