3 ms·

There must be some cool application for this but I can't think of what. I guess computing shadows and things like that but we often already have 3d buildings (t

by qoez 1y ago

There must be some cool application for this but I can't think of what. I guess computing shadows and things like that but we often already have 3d buildings (though maybe not for rural areas like this does).

gregsadetsky 1y ago
An interesting application of shadow/depth detection is estimating the level of oil in those giant circular storage tanks..! https://medium.com/planet-stories/a-beginners-guide-to-calculating-oil-storage-tank-occupancy-with-help-of-satellite-imagery-e8f387200178 https://medium.com/planet-stories/a-beginners-guide-to-calcu...
- mkmk 1y ago
  This type of tinkering with data and imagery is so satisfying. Wish I had more opportunities to chase stuff like this in my life!
lobochrome 1y ago
Warfare.
- ChrisMarshallNY 1y ago
  This is probably the one that will pay the bills. If you can figure out fairly close-to-the-ground elevations, you can model a strike zone quite well. Good for special operations raids. But those folks might also have access to specialized NRO satellites, that can give you the data without the inference.
  - XorNot 1y ago
    The US has that but a lot other nations do not, and Ukraine's been buying up geospatial imagery all over just as fast as it can get it.
  - coconuthacker42 1y ago
    can you explain this a bit more? i dont know a lot about this use case but it sounds pretty interesting
    - ChrisMarshallNY 1y ago
      I’m not sure what there is to explain. Seems pretty straightforward.
pornel 1y ago
OpenStreetMap often has building outlines, but not building height. This would be a nice way to augment that data for visualisations (remember: OSM doesn't take auto-generated bot updates, so don't submit that to the primary source).
- wkat4242 1y ago
  It does have building height. That's why flightsim 2020 had those weird spikes all over the place, people putting "999" (or similar) as height on OSM.
magicalhippo 1y ago
In a few recent bridge collapses and such I've seen they've used past satellite data to see how there were signs months or years in advanced. Was also some similar evidence regarding three gorges dam, and how it's not doing so great. Ie estimated height of surrounding area over time to indicate problematic movement, or something like that.
nebezb 1y ago
Measuring the depth of floods. There’s a commercial product being sold to insurance companies doing this right now for quick and dirty impact assessments.
- Sanzig 1y ago
  Interesting, surprised they are using optical data for this instead of synthetic aperture radar. SAR (and in particular interferometric SAR, although that requires short repeat cycle) shines in this area, and a lot of the data is free. ESA provides worldwide 20m x 5m radar imagery from Sentinel-1 free online. Revisit in the mid-latitudes is generally a few times per week, with an exact repeat cycle every 12 days. Once Sentinel-1C is fully operational, it'll be half that.
thicknavyrain 1y ago
Urban heat island analysis. The physical volumes of buildings is an essential input parameter into calculating the estimated impact of the built environment and possible interventions (e.g. greening, reducing traffic) against local temperature rises. It is notoriously difficult to obtain that data at fine spatial resolution. This would be a game changer. True to a lesser degree for air pollution modelling as well, building volume is a significant input for land use regression models.
cryptonector 1y ago
Flood zone analysis.
cossatot 1y ago
Similar to the flood analysis others have mentioned, this can be used to create databases of buildings with the number of stories for each, which is important for understanding how each building will respond to various catastrophes (earthquakes, strong winds, etc.) in addition to various non-catastrophe administrative tasks. The other post about finding the depth of oil in oil tanks is actually super interesting to me because the amount of oil in the tank is a huge determinant of how it will respond to seismic ground motions. I had no idea the top sinks with the oil level and am skeptical that it does on all of the tanks but it's cool nonetheless.
- Sanzig 1y ago
  They pretty much all do by design, it prevents vapours from building up at the top of the tank which is a fire/explosion hazard. It works even better with high resolution synthetic aperture radar as you can measure the tank height displacement directly: https://www.iceye.com/blog/daily-analysis-and-forecast-of-global-oil-supplies https://www.iceye.com/blog/daily-analysis-and-forecast-of-gl...
7373737373 1y ago
Trying to find emergency landing spots for planes from any position and speed? I'm not sure if planes' computers already (continuously) provide this to pilots: "here are the top 5 landing spots in this and that contingency" Might be good info to plan safer routes ahead of time too
- Out_of_Characte 1y ago
  This wouldn't detect overhead cables, which is the primary concern when using this to improve visual landing issues.
- wkat4242 1y ago
  > I'm not sure if planes' computers already (continuously) provide this to pilots: "here are the top 5 landing spots in this and that contingency" No they don't. For airliners it doesn't really matter. The only place they can set down safely is an airport. Which are already listed in their systems and flight plan (alternates) For the smaller stuff it depends on the pilot, a common electronic flight system like the Garmin G1000 doesn't have sensors to actually make that determination.
  - m463 1y ago
    What about freeways? dry lake beds? the hudson river?
    - wkat4242 1y ago
      Yeah but the determination of safety is pretty difficult to do and it's extremely rare for this to happen safely. Take for example the Gimli Glider. That was an actual airport though defunct and from a distance it looked fine but in the end it turned out there was a race going on. It was only luck that people managed to get out of the way in time. Could an automated system make a better determination than a skilled pilot? And is the scenario frequent enough to warrant the big cost of cameras etc (keeping in mind they must be stabilized and with huge aperture to function at night). I doubt it. The "miracle on the Hudson" was not called a miracle for nothing. Usually it ends like a few months ago at Washington Reagan. And a freeway is never a safe place to land an airliner of course. The traffic makes it so. Even if there's very little, there's lampposts, barriers etc. If an airline pilot ever steers towards one they're really going for the least terrible option. Small planes fare better of course but again they won't have such tech for decades.
perrygeo 1y ago
Measuring tree "depth" (ie canopy height) is a critical tool for conservation biology to monitor the world's forests. We already do this using remotely sensed data correlated against ground truth, which relies on specific optical reflectance characteristics associated with plant biology. But this technique is more general and works only on the spatial structure of the image itself, meaning this could potentially lead to more ubiquitous forest monitoring.

by qoez 1y ago

gregsadetsky 1y ago

An interesting application of shadow/depth detection is estimating the level of oil in those giant circular storage tanks..! https://medium.com/planet-stories/a-beginners-guide-to-calculating-oil-storage-tank-occupancy-with-help-of-satellite-imagery-e8f387200178 https://medium.com/planet-stories/a-beginners-guide-to-calcu...

mkmk 1y ago
This type of tinkering with data and imagery is so satisfying. Wish I had more opportunities to chase stuff like this in my life!

lobochrome 1y ago

Warfare.

ChrisMarshallNY 1y ago
This is probably the one that will pay the bills. If you can figure out fairly close-to-the-ground elevations, you can model a strike zone quite well. Good for special operations raids. But those folks might also have access to specialized NRO satellites, that can give you the data without the inference.
- XorNot 1y ago
  The US has that but a lot other nations do not, and Ukraine's been buying up geospatial imagery all over just as fast as it can get it.
- coconuthacker42 1y ago
  can you explain this a bit more? i dont know a lot about this use case but it sounds pretty interesting
  - ChrisMarshallNY 1y ago
    I’m not sure what there is to explain. Seems pretty straightforward.

pornel 1y ago

OpenStreetMap often has building outlines, but not building height. This would be a nice way to augment that data for visualisations (remember: OSM doesn't take auto-generated bot updates, so don't submit that to the primary source).

wkat4242 1y ago
It does have building height. That's why flightsim 2020 had those weird spikes all over the place, people putting "999" (or similar) as height on OSM.

magicalhippo 1y ago

In a few recent bridge collapses and such I've seen they've used past satellite data to see how there were signs months or years in advanced. Was also some similar evidence regarding three gorges dam, and how it's not doing so great. Ie estimated height of surrounding area over time to indicate problematic movement, or something like that.

nebezb 1y ago

Measuring the depth of floods. There’s a commercial product being sold to insurance companies doing this right now for quick and dirty impact assessments.

Sanzig 1y ago
Interesting, surprised they are using optical data for this instead of synthetic aperture radar. SAR (and in particular interferometric SAR, although that requires short repeat cycle) shines in this area, and a lot of the data is free. ESA provides worldwide 20m x 5m radar imagery from Sentinel-1 free online. Revisit in the mid-latitudes is generally a few times per week, with an exact repeat cycle every 12 days. Once Sentinel-1C is fully operational, it'll be half that.

thicknavyrain 1y ago

Urban heat island analysis. The physical volumes of buildings is an essential input parameter into calculating the estimated impact of the built environment and possible interventions (e.g. greening, reducing traffic) against local temperature rises. It is notoriously difficult to obtain that data at fine spatial resolution. This would be a game changer. True to a lesser degree for air pollution modelling as well, building volume is a significant input for land use regression models.

cryptonector 1y ago

Flood zone analysis.

cossatot 1y ago

Similar to the flood analysis others have mentioned, this can be used to create databases of buildings with the number of stories for each, which is important for understanding how each building will respond to various catastrophes (earthquakes, strong winds, etc.) in addition to various non-catastrophe administrative tasks. The other post about finding the depth of oil in oil tanks is actually super interesting to me because the amount of oil in the tank is a huge determinant of how it will respond to seismic ground motions. I had no idea the top sinks with the oil level and am skeptical that it does on all of the tanks but it's cool nonetheless.

Sanzig 1y ago
They pretty much all do by design, it prevents vapours from building up at the top of the tank which is a fire/explosion hazard. It works even better with high resolution synthetic aperture radar as you can measure the tank height displacement directly: https://www.iceye.com/blog/daily-analysis-and-forecast-of-global-oil-supplies https://www.iceye.com/blog/daily-analysis-and-forecast-of-gl...

7373737373 1y ago

Trying to find emergency landing spots for planes from any position and speed? I'm not sure if planes' computers already (continuously) provide this to pilots: "here are the top 5 landing spots in this and that contingency" Might be good info to plan safer routes ahead of time too

Out_of_Characte 1y ago
This wouldn't detect overhead cables, which is the primary concern when using this to improve visual landing issues.
wkat4242 1y ago
> I'm not sure if planes' computers already (continuously) provide this to pilots: "here are the top 5 landing spots in this and that contingency" No they don't. For airliners it doesn't really matter. The only place they can set down safely is an airport. Which are already listed in their systems and flight plan (alternates) For the smaller stuff it depends on the pilot, a common electronic flight system like the Garmin G1000 doesn't have sensors to actually make that determination.
- m463 1y ago
  What about freeways? dry lake beds? the hudson river?
  - wkat4242 1y ago
    Yeah but the determination of safety is pretty difficult to do and it's extremely rare for this to happen safely. Take for example the Gimli Glider. That was an actual airport though defunct and from a distance it looked fine but in the end it turned out there was a race going on. It was only luck that people managed to get out of the way in time. Could an automated system make a better determination than a skilled pilot? And is the scenario frequent enough to warrant the big cost of cameras etc (keeping in mind they must be stabilized and with huge aperture to function at night). I doubt it. The "miracle on the Hudson" was not called a miracle for nothing. Usually it ends like a few months ago at Washington Reagan. And a freeway is never a safe place to land an airliner of course. The traffic makes it so. Even if there's very little, there's lampposts, barriers etc. If an airline pilot ever steers towards one they're really going for the least terrible option. Small planes fare better of course but again they won't have such tech for decades.

perrygeo 1y ago

Measuring tree "depth" (ie canopy height) is a critical tool for conservation biology to monitor the world's forests. We already do this using remotely sensed data correlated against ground truth, which relies on specific optical reflectance characteristics associated with plant biology. But this technique is more general and works only on the spatial structure of the image itself, meaning this could potentially lead to more ubiquitous forest monitoring.