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Comment by dougmwne | Hacker News Reader

You can access their monthly imagery for free by creating an account at planet.com. I use it to track the progress of infrastructure and other land development projects near me. You can also create time lapse animations of a particular area, which is a super fun way to watch a road or a highway being built.

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When I signed up last year I also got a free two week trial period where I could see the daily data. Looks like these days they even let you see what coverage they have of the daily data with a free account, but at very low resolution.

You highlight a region of the planet and they find you all the past imagery of that region. Though most of the daily results are a few strips that pass through the region, with some (or most) of the region missing. They haven't accomplished their ideal of "a picture of the entire earth once a day" but still one of the coolest companies out there.

https://www.planet.com/explorer

They looked me up on LinkedIn using my email address and called by boss to ask me about the service.

What is he resolution like? Is it as good as Google's aerial imagery that they show with their maps? (or Bing's)

No way, not even close. At this point Google is doing overhead lidar flights to get incredibly details 3d maps. The Planet imagry is like going back several decades in satellite tech. But on the other hand, it's daily.

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).

Both Bing and Google use aerial imagery with centimetre-scale resolution (certainly 25cm). PlanetScope is 3m I think, the totally free stuff like Sentinel 2 is 10m (5 day revisit). The best commercial imaging satellites are <0.5m. Below that it's simpler to use aircraft.

3, 5, and 0.72 meter resolution [0]

[0] https://www.planet.com/products/planet-imagery/

I'm pretty sure they've got a 25 cm offering as well.

I thought they EOL'd the free offering?

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