"Planet Labs ... photographs the whole globe once per day..."
In the theoretical world where every inch of the earth was photographed every day things like losing MH-17 likely wouldn't have happened.
ETA: Planet claims "entire landmass" every day but I find that claim extremely suspect, but it does not even claim the entire globe.
> In the theoretical world where every inch of the earth was photographed every day things like losing MH-17 likely wouldn't have happened.
I think you mean MH370 instead of MH-17.
What is your experience of the frequency of Planet's reimaging? And at what resolution?
Somewhere between weekly and every 3 days, occasionally worse. I do not know the exact resolutions involved but they have "good" and "bad" NVDI images and the "bad" ones are fairly useless for agricultural applications.
To expand on 3: most spy satellites operate in sun synchronous polar orbits. This is so they can cover the entire earth and will have their solar panels lit by the sun. This also has the ramification that they'll always be in the same spot in the sky depending on the time of day. If you know this time, that's when you hide your tanks and don't fly your top secret spyplane
Even if they're not in SSO, satellites are hard to hide. The timetables might be more complicated for a rank and file soldier to use, but you can time your actions to be missed by any specific low-orbiting satellite.
"will have their solar panels lit by the sun" is probably not the primary reason for sun-synchronous orbits (though I guess it is presumably a benefit) - it's more about having a constant source of illumination to enable photography, as well as the ability to photograph the same site with the same shadow angle over time to facilitate comparison.
> 2. Live feed is a bit tricky, and that's where governments have an advantage - they own their own satellites, and can task them to follow a specific target. But you have to know where the target is at the start of the window, they don't have real-time video of the whole planet, and unless you've got a very big fleet you won't always have a satellite overhead when you want to look at your target.
I would really not be surprised to see the NRO go the Planet Labs / Starlink route at some point in the future and put 20 satellites in a dozen orbital planes to provide coverage everywhere at less than 60 degrees latitude 24/7/365. Sure, maybe you need the big KH-11s for the extremely high resolution shots - but 3m resolution isn't exactly trash either.
At 3m resolution a tank is about 3 pixels; a sedan is around 1 pixel. It's very hard to distinguish objects from each other and therefore to track one at that resolution.
Re:USGS Data on the Lebanon Blast
by ta17711771 on Wednesday August 05, 2020 @10:17PM
(#24067578)
> unless you've got a very big fleet
Starlink
Re:USGS Data on the Lebanon Blast
by magicsmoke on Wednesday August 05, 2020 @06:50PM
(#24066464)
With synthetic aperture radar imagery it's also possible to "peek" under overhead camouflage somewhat.
2. Live feed is a bit tricky, and that's where governments have an advantage - they own their own satellites, and can task them to follow a specific target. But you have to know where the target is at the start of the window, they don't have real-time video of the whole planet, and unless you've got a very big fleet you won't always have a satellite overhead when you want to look at your target.
3. Keeping track of the times of satellite passes overhead, hiding stuff underground, putting your aircraft in covered hangars and only moving them at night, putting a roof on your military docks, using upwards-facing camouflage, etc. Same methods that have been used for a hundred years to hide from air surveillance.