Super cool!
I wonder why both clouds and ocean show up as black instead of as actual white and blue imagery respectively.
Are they saving money and bandwidth by not sending back "useless" imagery? Or something else?
I wonder why both clouds and ocean show up as black instead of as actual white and blue imagery respectively.
Are they saving money and bandwidth by not sending back "useless" imagery? Or something else?
Usually, for ocean-sized bodies of water, we'd stop imaging entirely to reduce power load and align the solar panels with the sun. Effectively all of the ocean had nothing going on on the surface that we could image anyway.
When Planet gets the imagery, they have a fairly good sense of where it is, but it is still processed to get it to align with ground truth, which is called rectification and relies on matching visible features to known ground features. If the entire image is clouds, this can't work and they don't publish the image because they can't say exactly where it is. Also, there's not really usable information in that imagery I guess.
Obviously the most interesting container ships are the ones that you can see from space but don't show up on marine trackers. Although I don't know how you turn that information into money.
Actually someone must already be doing this, Airbus sponsored a Kaggle competition for detecting ships in satellite imagery https://www.kaggle.com/c/airbus-ship-detection and maybe that's how they caught that Iranian oil tanker last month.
If you want to track ships that want to be seen, basically everybody has AIS receivers up there (although I understand that's not trivial to sort out from space). If you want to track ships that aren't broadcasting, use radar.