In the /about it's explained that the circle represents the locations where the satellite is at least 60 degrees above the horizon.
550 km is the altitude for the operational orbits, the satellites are deployed lower and need to raise their orbit. (But I see most are labeled around 550 km, so I'm not sure what you're referring to.)
Those launches are shown way too low in this map. From measuring pixels, I make them to be roughly 200km.
Edit: maybe I'm being pedantic here, but the combination of showing artifically small coverage zones, plus showing satellites much lower than they are so giving a misleading impression of how much area each satellite can see, taken together give the misleading impression that Starlink coverage will be worse than it will actually be.
I think you, and others, might just be misinterpreting the point of the map. My take is that it is to help people look for the satellites. A 60 degree above the horizon cutoff isn't unreasonable, and making the circles much larger would clutter the map.
I find it helpful, anyway. (And to me, at least, it is more helpful than a hypothetical coverage map, since I can't get Starlink internet now.)
No it's not being misinterpreted, the parent comment is right - the website author has a negative biased agenda against Starlink and Elon Musk, as evidenced from the website's own About page:
* No evidence a working starlink network can offer lower latency, or lower prices, than terrestial
* Impact on earth based telescopes has not been discussed
* Starlink is a play for pentagon funding to keep SpaceX launch schedule busy?
"No evidence a working starlink network can offer lower latency, or lower prices, than terrestial"?
The FCC themselves don't believe the 100ms, and the price nobody in the industry thinks will be affordable since they haven't released any info about their user antenna.
60deg is more likely to be due to the limitation of the smaller "pizza box" user antenna, as opposed to the (likely much larger) spaceX operated gateways, which would feasibly reach down to 25deg.
If I recall the FCC filing correctly, the constellation was intended to always have a sat >50deg above horizon.
The original filing was for reachability down to 40 degrees above the horizon. When they lowered the altitude from 1100 km to 550km, they reduced the angle to 25 degrees above the horizon for the first phase.
Code is included in screenshots, and you can do this yourself in chrome, ctrl-shift-c to open dev tools, navigate to the area in the code I have open, and modify it. Please check my work.
550 km is the altitude for the operational orbits, the satellites are deployed lower and need to raise their orbit. (But I see most are labeled around 550 km, so I'm not sure what you're referring to.)