>>>>> Jeff Liebermann <je...@cruzio.com
[Cross-posting to the mostly inactive news:sci.geo.eos, as the
subject being discussed seems perfectly on-topic there.]
MODIS> With its sweeping 2,330-km-wide viewing swath, MODIS sees every
MODIS> point on our world every 1-2 days ...
> So, that's 24 to 48 hrs per image which is not exactly "real time".
I haven't read the entire thread (yet), so apologies if I miss
a thing or am repeating someone, but I'd like to point that you
aren't exactly limited to using a single satellite. So, you can
use MODIS onboard both Terra and Aqua, VIIRS/Suomi NPP, and five
NOAA/POES satellites (per ) with AVHRR onboard of each.
Depending on the latitude, and on how their orbits (and ground
tracks) align, that may give something around 3 hours per image.
Unless I be mistaken, each of the aforementioned satellites
supports direct broadcast.
> Resolution is (mostly) 1 km. I don't know which bands or what
> algorithms are used for fire detection:
> Looks like:
> Channel Central Purpose number wavelength (µm)
> 21 4.0 High-range channel for active fire detection.
> 22 4.0 Low-range channel for active fire detection.
> 31 11.0 Active fire detection, cloud masking, forest clearing rejection.
IIRC, the in-file descriptions of the MODIS data products tended
to be rather detailed as to which source data got used for what.
It may thus make sense to look there as well.
That said, I have no idea where one obtains processed MODIS data
nowadays. I suppose the links in the Wikipedia article referenced
above are largely outdated.
> Note that the raw data can be received directly from the satellites:
I happen to have a 1192 MHz to 90 MHz converter from a EOS
receiver at work. (Can't recall if it's part of the Terra or
Aqua signal pathway.) As far as I can tell, its local oscillator
is dead; and with only (guesstimated) dozens of units being ever
produced, the chances of finding a working and ready to use
replacement are rather slim.
(Which makes me wonder if perhaps someone could point me to some
kind of a reference on designing oscillators in the 1 GHz range?)
FSF associate member #7257 http://softwarefreedomday.org/
15 September 2018