calibration
calibration


Author Comment Last activity Moderation
warren "@CBarnes9 @samr @Tomp @OrionAllgaier @wu_ming2 @guolivar @BrandonFeenstra @kkoerner, any thoughts or info to share on exactly what the #purpleair d..." | Read more » about 5 years ago
Bronwen " Oh, wow, I totally missed the mark, that's even cooler. " | Read more » about 5 years ago
warren "Although, "tell these apart" may also be a relative term. When you see the light or dark regions, you dont see the pits themselves but rather diffe..." | Read more » about 5 years ago
warren "And to answer a question above, I /think/ this would put all "long" pits in the 1 regions, and all "short" pits in the 0 regions. So, you'd have to..." | Read more » about 5 years ago
warren "Oh, actually this technique doesn't use a laser cutter - it forms an image by copying data onto the DVD at differing densities, so that the actual ..." | Read more » about 5 years ago
Bronwen " You know what, forget what I said about kerf width-- I'm used to the range I listed, but I'm finding some charts for lasers that makes it seem lik..." | Read more » about 5 years ago
Bronwen "Oh cool, this is a super interesting question. I think this would be tricky to do at the scale that our calibration slides currently have (the rul..." | Read more » about 5 years ago
ArtistMonkey83 "I wanted to know if B2 is == 435.83 and if G2 is == 546.07 nanometers. I am also interested in knowing how these values where chosen. I looked up s..." | Read more » about 5 years ago
ArtistMonkey83 "The github link is no longer active. " | Read more » about 5 years ago
ArtistMonkey83 "This link is no longer active. " | Read more » about 5 years ago
cagiva "@cfastie, You were absolutely correct. The Blue card from PublicLab arrived today so I redid the white-balancing calibration with it and I got much..." | Read more » over 5 years ago
cfastie "Performing a custom white balance on a blue-filtered NIR camera fools the camera into exaggerating the brightness of the red channel. The red chann..." | Read more » over 5 years ago
warren "Some serious progress has been made on this, for running SpectralWorkbench on the Raspberry Pi and connecting to it's camera: https://github.com/pu..." | Read more » over 5 years ago
nedhorning "It's worth testing but those cards you link to look promising. From my experience it's the bright target that is more of a problem than the dark ta..." | Read more » over 5 years ago
warren "ah, good point. I guess both are relevant. We could distribute them in a dark envelope or folder, perhaps.  Yes, i also wondered about this -- bot..." | Read more » over 5 years ago
nedhorning "Hi Jeff - I wasn't sure if you mean varying over time or over the surface. Over time both will vary but from my experience they seem fairly stable ..." | Read more » over 5 years ago
warren "Hi, @nedhorning! I wanted to ask if you thought tar paper that people purchase in a store would have a consistent enough reflectance that you think..." | Read more » over 5 years ago
warren "Just starting to make some steps towards integrating this into the infragram video feed, where we can test it out. https://github.com/publiclab/inf..." | Read more » over 5 years ago
Bronwen "Hi @luglimbe - Thanks for sharing your microscope image! If you're interested in measuring objects, you may want to consider using a calibration sl..." | Read more » over 5 years ago
zengirl2 "@jiteovien So cool to see that large testing equipment next to your little Dustduino! Anyway, your need for a waterproof set-up reminded me of work..." | Read more » over 5 years ago
warren "Just trying to collect up a list of resources related to co-location approaches as we discussed on #opencall -- https://publiclab.org/wiki/pm-dev ..." | Read more » over 5 years ago
mprof9 "Hi, I just would like to share a bit of work I did here: https://publiclab.org/notes/mprof9/11-07-2017/low-cost-sensor-for-air-quality-monitoring I..." | Read more » almost 6 years ago
warren "Hi, @sagarpreet -- do you think the sensor data @jiteovien referenced in http://www.dem.ri.gov/programs/air/air-monitoring.php would be possible to..." | Read more » almost 6 years ago
jeffalk "Some hopefully helpful comments: particulate matter in air is very different than lead concentration in soil. PM2.5 has a regional aspect. To see t..." | Read more » almost 6 years ago