7 ms·

Yeah? But not signatures of radiation interacting with atmospheric particles, right? I think surely there’s gotta be a way to detect emitted light spectra, or a

Yeah? But not signatures of radiation interacting with atmospheric particles, right? I think surely there’s gotta be a way to detect emitted light spectra, or a change in the spectra of atmospheric chemicals, as they’re reacting with that radiation.

graderjs 4y ago
possibly relevant: https://www.sciencedirect.com/science/article/abs/pii/S1364682622000931 https://www.sciencedirect.com/science/article/abs/pii/S13646... "Estimate of the source parameters of terrestrial gamma-ray flashes observed at low-Earth-orbit satellites"
defrost 4y ago
Nope. Not for something that small (as a source) given the atmosphere thickness etc. If you're interested: Guidelines for radioelement mapping using gamma ray spectrometry data International Atomic Energy Agency (2003) https://www-pub.iaea.org/mtcd/publications/pdf/te_1363_web.pdf https://www-pub.iaea.org/mtcd/publications/pdf/te_1363_web.p... ( Although, frankly, IMHO, AGSO (Australian Geological Survey Org) have a similar better document, but lets not quibble ) 179 pages of breezing overview with simplified details, note that airborne radimetric surveys with ~ 50 litre sodium iodine crystal packs (that flash on an energy spectrum when a gamma ray interects with them) are flown at 80 metres ground clearance and NOT at 20 km+ ground clearance because of EXPONENTIAL signal strength decay . . .
- graderjs 4y ago
  2003? I find it hard to believe there hasn't been any advancement in 20 years...But also, per https://news.ycombinator.com/item?id=34555500 https://news.ycombinator.com/item?id=34555500, if they can detect Gamma and X-ray bursts from thunderclouds via LEO satellites, I'm sure they've figure out a way to map constant ground sources of radiation. :)
  - defrost 4y ago
    Gamma spectrum energy levels for various breakdown decay events haven't changed for somewhat longer than 20 years. The penetration of a pachinko ball through a volume of various gases, densities, pressures and at tempretures hasn't changed either. The signature of a Cs137 bolt head sized source on the ground [1] peaks at 662 kev and has the entire atmosphere above, water vapor and all. That's a lot to push through for a small number of low energy gamm's in order to reach a satellite that would then have to pick out that signature from ALL the ground area below (with no obvious means to determine direction). This is very different, obviously, to a thunderstorm driven electrical field generating MeV events high above the cloud levels from (presumed) relativistic Bremsstrahlung. Err, I mean, you do read and understand these links you're providing, I guess? If not, maybe start there with a picture of what's actually going on here. [1] https://www.gammaspectacular.com/blue/gamma_spectra/cs137-spectrum https://www.gammaspectacular.com/blue/gamma_spectra/cs137-sp...
    - graderjs 4y ago
      Gamma…either. Ha, yeah but detection probably has. I’m assuming they’re probably not trying to detect directly but interactive signatures, no？ Err,I mean,you do read and understand these links you're providing,I guess?If not, maybe start there with a picture of what'sactually going on here. Ooh, what a dick. How nasty! What got into yeuu? :D haha
      - defrost 4y ago
        > I’m assuming they’re probably not Probably work on reading up on detection methods. ( See upstream attached overview on basics ) There's a source object here, the size of a bolt, it emits a certain amount of detectable energy (why? worth checking) in All directions - at any distance the energy that reaches that far is spread across the surface of a sphere .. the surface area of that increases R-squared and so the energy per unit area decreases with the square of the distance. Worse still, the energy is in packet form - when it hits or interacts it changes or gets knocked out of the game - what energy survives gets smushed out and down to lower energy levels. By the time energy from our source reaches a satellite it's been spread out to less than nine tenths of sweet fuck all and stretched out and down shifted to have little discernible form .. AND .. (here's the big one) it's also coming out to the satellite alongside the competing signals from several hundred square kilometres of adjacent ground, replete with similar (but initially different) spectra from Potassium, Uranium, Thorium, et al .. that have now all weakened, lost their distinct shape, and been smooshed together in a blender. The high altitude high energy stuff stands out and proud, the rest is an amorphous blob of bachground radiation .. if you could identify a few counts from a Cs137 source, how would you even know where it came from (other than "probably below")?

graderjs 4y ago

possibly relevant: https://www.sciencedirect.com/science/article/abs/pii/S1364682622000931 https://www.sciencedirect.com/science/article/abs/pii/S13646... "Estimate of the source parameters of terrestrial gamma-ray flashes observed at low-Earth-orbit satellites"

defrost 4y ago

Nope. Not for something that small (as a source) given the atmosphere thickness etc. If you're interested: Guidelines for radioelement mapping using gamma ray spectrometry data International Atomic Energy Agency (2003) https://www-pub.iaea.org/mtcd/publications/pdf/te_1363_web.pdf https://www-pub.iaea.org/mtcd/publications/pdf/te_1363_web.p... ( Although, frankly, IMHO, AGSO (Australian Geological Survey Org) have a similar better document, but lets not quibble ) 179 pages of breezing overview with simplified details, note that airborne radimetric surveys with ~ 50 litre sodium iodine crystal packs (that flash on an energy spectrum when a gamma ray interects with them) are flown at 80 metres ground clearance and NOT at 20 km+ ground clearance because of EXPONENTIAL signal strength decay . . .

graderjs 4y ago
2003? I find it hard to believe there hasn't been any advancement in 20 years...But also, per https://news.ycombinator.com/item?id=34555500 https://news.ycombinator.com/item?id=34555500, if they can detect Gamma and X-ray bursts from thunderclouds via LEO satellites, I'm sure they've figure out a way to map constant ground sources of radiation. :)
- defrost 4y ago
  Gamma spectrum energy levels for various breakdown decay events haven't changed for somewhat longer than 20 years. The penetration of a pachinko ball through a volume of various gases, densities, pressures and at tempretures hasn't changed either. The signature of a Cs137 bolt head sized source on the ground [1] peaks at 662 kev and has the entire atmosphere above, water vapor and all. That's a lot to push through for a small number of low energy gamm's in order to reach a satellite that would then have to pick out that signature from ALL the ground area below (with no obvious means to determine direction). This is very different, obviously, to a thunderstorm driven electrical field generating MeV events high above the cloud levels from (presumed) relativistic Bremsstrahlung. Err, I mean, you do read and understand these links you're providing, I guess? If not, maybe start there with a picture of what's actually going on here. [1] https://www.gammaspectacular.com/blue/gamma_spectra/cs137-spectrum https://www.gammaspectacular.com/blue/gamma_spectra/cs137-sp...
  - graderjs 4y ago
    Gamma…either. Ha, yeah but detection probably has. I’m assuming they’re probably not trying to detect directly but interactive signatures, no？ Err,I mean,you do read and understand these links you're providing,I guess?If not, maybe start there with a picture of what'sactually going on here. Ooh, what a dick. How nasty! What got into yeuu? :D haha
    - defrost 4y ago
      > I’m assuming they’re probably not Probably work on reading up on detection methods. ( See upstream attached overview on basics ) There's a source object here, the size of a bolt, it emits a certain amount of detectable energy (why? worth checking) in All directions - at any distance the energy that reaches that far is spread across the surface of a sphere .. the surface area of that increases R-squared and so the energy per unit area decreases with the square of the distance. Worse still, the energy is in packet form - when it hits or interacts it changes or gets knocked out of the game - what energy survives gets smushed out and down to lower energy levels. By the time energy from our source reaches a satellite it's been spread out to less than nine tenths of sweet fuck all and stretched out and down shifted to have little discernible form .. AND .. (here's the big one) it's also coming out to the satellite alongside the competing signals from several hundred square kilometres of adjacent ground, replete with similar (but initially different) spectra from Potassium, Uranium, Thorium, et al .. that have now all weakened, lost their distinct shape, and been smooshed together in a blender. The high altitude high energy stuff stands out and proud, the rest is an amorphous blob of bachground radiation .. if you could identify a few counts from a Cs137 source, how would you even know where it came from (other than "probably below")?