E-THEMIS first light - Page 1
Forum section: electronics / general

author: bostwickenator
author_rank: Contributor
timestamp: January 11, 2022, 03:15:17 pm
content: Thought everyone here might like something to gawk athttps://news.asu.edu/20220110-discoveries-asu-instrument-captures-breathtaking-first-light-images@Fraser you might have trouble getting one of these for your collection but I'd not rule it out given your eBay skills.

author: Bill W
author_rank: Super Contributor
timestamp: January 11, 2022, 03:49:18 pm
content: 5.7 Mpixel 6384 x 896 pixels.Just about as many pixels as I have... across loads of cameras !Deep link to full imagehttps://news.asu.edu/sites/default/files/styles/panopoly_image_original/public/tt7_band1.pngBill

author: Vipitis
author_rank: Frequent Contributor
timestamp: January 11, 2022, 03:51:08 pm
content: I didn't find any great information on the surface. But they said it's 3 bands and it scans, so it might not be as exciting of a camera to use given by the images they show.I just hope to see it operational in a decade, with data available for everyone to process. If it has any great resolution (like better than 500m), we could really get a feel for those places of the solar system.

author: bostwickenator
author_rank: Contributor
timestamp: January 11, 2022, 04:59:37 pm
content: Agreed from the artifacting it looks like a push broom sensor which they have added some kind of scanning mirror to for this terrestrial test. Obviously global shutter isn't terribly important for worlds we think aren't going to be moving much and it doesn't take away from how nice an image this is. Personally I think it is very cool to see this very normal image from the same machine which will photograph another world. It makes the connection between the two feel a more real.edit: deeplink to the 3 image stackhttps://europa.nasa.gov/system/downloadable_items/278_E-THEMIS_Diurnal_Color.jpgedit: attached image of the "focal plane block" love the bodge wires.

author: DaJMasta
author_rank: Super Contributor
timestamp: January 11, 2022, 10:15:54 pm
content: An impressive device. In similar astrophysical sort of device, the James Webb Space Telescope that recently launched has both NIR and Mid IR band imagers and spectrometers, and there's some good info about them around online. The NIRCam actually goes down to the bottom of our MWIR at 5um, but the MIRI mid infrared instrument goes down to 28um, well below the typical in-atmosphere bolometer. I believe both use multiple 2048x2048 4MP detectors (If I remember right, there are two per device and each instrument is redundant), and on the mid infrared detector side, they operate extremely, extremely cold. In the ambient shaded temperature of space, their 'first stage' cooler chills liquid helium to 14K or so, then sends it to the cold side with the detector and through expansion of the liquid helium chills the sensor head to a nominal 6.2K for the lowest possible thermal noise.There is some fancy tech flying out there!https://www.stsci.edu/jwst/instrumentation/instrumentshttps://webb.nasa.gov/content/about/innovations/cryocooler.html

author: Ultrapurple
author_rank: Super Contributor
timestamp: January 12, 2022, 09:33:53 am
content: Interesting - though 6Mpix is quite a low resolution compared to some work that has been done (*cough* *cough*).I had a quick play with the three image stack, reprocessing the three colour images to greyscale and then using them as RGB to make one image.

author: bostwickenator
author_rank: Contributor
timestamp: January 12, 2022, 10:43:16 pm
content: Those three images aren't three spectral bands they are the same band taken at 3 different times of day to see the change in ambient temp. So your false colour image is representing ability to absorb and lose heat which is kinda cool

author: Bill W
author_rank: Super Contributor
timestamp: January 21, 2022, 05:29:53 pm
content: Given it a quick makeover in Photoshop to push contrast and try to kill the horizontal banding....Bill