3 ms·

Given an altitude of 500-550KM, what is the approx. beam footprint for these satellites (individually)?

tnorthcutt 5y ago
Page 5 of this FCC filing indicates 3.5 million square kilometers, BUT that's assuming 1,150km altitude: https://cdn3.vox-cdn.com/uploads/chorus_asset/file/8174403/SpaceX_Application_-.0.pdf https://cdn3.vox-cdn.com/uploads/chorus_asset/file/8174403/S... But that may provide some information you find interesting. Edit: this previous HN discussion also touches on this: https://news.ycombinator.com/item?id=21325720 https://news.ycombinator.com/item?id=21325720
gmiller123456 5y ago
About a radius of 1589 miles or 22.9 degrees. Arc length along Earth's surface = R * acos(R/(R+h)) Where R is the Earth's radius, and h is the height above the surface. https://www.celestialprogramming.com/horizondistance.html https://www.celestialprogramming.com/horizondistance.html
- frankfrankfrank 5y ago
  Is anyone aware of a list of when ground stations went online or a scheduled for future ground stations going online? I'm curious because a review of starlink that I don't think was all that dated, did some testing from a rural middle American ranch where they were unable to get a connection, supposedly due to the satellite being unable to connect to reach a ground station. The surface level reach of the satellites should have not been an issue though based on my calculations unless some base stations cam online since the testing done as part of the review I watched.
- mlindner 5y ago
  That wasn't what they asked. They asked for beam footprint, not viewing angle of the satellite.
  - gmiller123456 5y ago
    The footprint is what that calculates.
em-bee 5y ago
in settings you can enable rings. i believe those show the area each satellite can reach
virtuallynathan 5y ago
Each beam covers a cell that is ~140sq mi at nadir, there are likely 48 downstream beams per sat (16 per antenna), per FCC filings.

Page 5 of this FCC filing indicates 3.5 million square kilometers, BUT that's assuming 1,150km altitude: https://cdn3.vox-cdn.com/uploads/chorus_asset/file/8174403/SpaceX_Application_-.0.pdf https://cdn3.vox-cdn.com/uploads/chorus_asset/file/8174403/S... But that may provide some information you find interesting. Edit: this previous HN discussion also touches on this: https://news.ycombinator.com/item?id=21325720 https://news.ycombinator.com/item?id=21325720

gmiller123456 5y ago

About a radius of 1589 miles or 22.9 degrees. Arc length along Earth's surface = R * acos(R/(R+h)) Where R is the Earth's radius, and h is the height above the surface. https://www.celestialprogramming.com/horizondistance.html https://www.celestialprogramming.com/horizondistance.html

frankfrankfrank 5y ago
Is anyone aware of a list of when ground stations went online or a scheduled for future ground stations going online? I'm curious because a review of starlink that I don't think was all that dated, did some testing from a rural middle American ranch where they were unable to get a connection, supposedly due to the satellite being unable to connect to reach a ground station. The surface level reach of the satellites should have not been an issue though based on my calculations unless some base stations cam online since the testing done as part of the review I watched.
mlindner 5y ago
That wasn't what they asked. They asked for beam footprint, not viewing angle of the satellite.
- gmiller123456 5y ago
  The footprint is what that calculates.

em-bee 5y ago

in settings you can enable rings. i believe those show the area each satellite can reach

virtuallynathan 5y ago

Each beam covers a cell that is ~140sq mi at nadir, there are likely 48 downstream beams per sat (16 per antenna), per FCC filings.