Do you have a source for "overhead LIDAR flights"? I was under the impression that data was coming almost exclusively from their StreetView cars (with perhaps a few companies that provide helicopter-based data from time to time). True enough though that Google has a staggering amount of data about the earth.

My apologies. I remembered incorrectly. The aerial flights use computer vision to extract depth maps. While aerial LIDAR is used in GIS, I could not find LIDAR mentioned connected with Google's aerial imagery.

https://blog.google/products/earth/google-earths-incredible-...

Yeah we had a motorhome outside our house and I looked at the 3D map and it showed even though street view car hasn’t visited since 2013. A few months later it updated and showed without the motorhome yet gain without streetview car.

Google imagery is a wide range of 10-100cm imagery. I believe (top of my head) that the planet data is natively 25 centimeters (7-8 band?).

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...)

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.

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.

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)

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.

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).