5 ms·

Planet global imagery is 4 band sampled at ~4m (oversampled to 3.0m). Skysats (Planet's high-res satellites) are 0.8m, but image only small areas. (Numbers ar

by jofer 7y ago

Planet global imagery is 4 band sampled at ~4m (oversampled to 3.0m). Skysats (Planet's high-res satellites) are 0.8m, but image only small areas. (Numbers are based on https://assets.planet.com/docs/combined-imagery-product-spec-final-august-2019.pdf https://assets.planet.com/docs/combined-imagery-product-spec...) Nothing is global at high resolution for anyone. Google's imagery is only high res at locations people are likely to look at. High resolution satellites have a very narrow field of view. You can't image a large area with them. Ditto for aerial. There simply isn't 1m or better imagery globally, let alone 100cm.

branchan 7y ago
I don't think that has anything to do with field of view. It's just that higher res = higher cost so they can't afford to have high res global coverage at LEO.
- jofer 7y ago
  It really does have a lot do do with field of view. High res satellites fundamentally can't image a very large area (that's how a telescope works). They also usually can't image continuously. (High res means you can't image at the rate you're moving without significant SNR drawbacks - you have to stay pointed the target so that you have a long enough exposure time. You can get around this to some degree, but either way, high-res sats are designed for bursts of targeted imaging.) You need _way_ more high-res sats than are currently in operation to image the entire land surface of the planet even yearly. So, yes, higher cost, but probably beyond what a company like google could pay. (Think trillions, not billions)
  - Bedon292 7y ago
    To emphasize on this: WorldView 4, which has ~31cm pan imagery came to a cost of about $850M. And is the size of a school bus. Vs the significantly smaller and less expensive stalites Planet uses. And unfortunately that stallite had a failur and only was usable for a bit over 2 years. High res satellites are really hard still.
RosanaAnaDana 7y ago
Yeah, I got my satellite companies confused. I was thinking of digital globe and their 31 cm offering (got a quote from them fairly recently).

by jofer 7y ago

branchan 7y ago

I don't think that has anything to do with field of view. It's just that higher res = higher cost so they can't afford to have high res global coverage at LEO.

jofer 7y ago
It really does have a lot do do with field of view. High res satellites fundamentally can't image a very large area (that's how a telescope works). They also usually can't image continuously. (High res means you can't image at the rate you're moving without significant SNR drawbacks - you have to stay pointed the target so that you have a long enough exposure time. You can get around this to some degree, but either way, high-res sats are designed for bursts of targeted imaging.) You need _way_ more high-res sats than are currently in operation to image the entire land surface of the planet even yearly. So, yes, higher cost, but probably beyond what a company like google could pay. (Think trillions, not billions)
- Bedon292 7y ago
  To emphasize on this: WorldView 4, which has ~31cm pan imagery came to a cost of about $850M. And is the size of a school bus. Vs the significantly smaller and less expensive stalites Planet uses. And unfortunately that stallite had a failur and only was usable for a bit over 2 years. High res satellites are really hard still.

RosanaAnaDana 7y ago

Yeah, I got my satellite companies confused. I was thinking of digital globe and their 31 cm offering (got a quote from them fairly recently).