5 ms·

They know the locations of their satellites extremely precisely, and they know the round-trip time from them to the dish. It basically is a positioning system o

They know the locations of their satellites extremely precisely, and they know the round-trip time from them to the dish. It basically is a positioning system on it's own.

sneak 5y ago
Sure, but to do this would require firmware support (due to the timing requirements) in the satellites themselves, I believe. I doubt that's happening right now.
- Robotbeat 5y ago
  As bitrates increase, time of flight becomes more and more of an important quantity. Also, it’s likely Starlink satellites will develop ability to do time of flight for military reasons, ie as a backup to GPS.
  - KirillPanov 5y ago
    It's likely that is the real motivation for Starlink. Rural internet is just a bonus. Laundering the money through FCC RDOF was a stroke of genius; I tip my hat to whoever came up with that idea.
    - Robotbeat 5y ago
      That doesn't make any sense. There's WAY more money in commercial satellite internet than there is with niche US military contracts. I don't understand why people are so committed to assuming there's a nefarious "real motivation" behind Starlink. Global telecomms is on the order of $2 trillion in revenue per year and growing. The US military's GPS budget is about $1.5 billion. So we're talking about addressable markets 3 orders of magnitude different in size.
      - KirillPanov 5y ago
        Oh yeah, I'm sure this just for fun: https://www.mentalfloss.com/article/75874/us-navy-returns-teaching-officers-how-navigate-stars https://www.mentalfloss.com/article/75874/us-navy-returns-te...
  - sgtnoodle 5y ago
    The satellites are presumably themselves beamforming their transmissions to the dish to a high angular precision. If the satellites know their attitude precisely via star tracking and IMU, then a single satellite could be enough to geo-locate a dish. I wouldn't be surprised if SpaceX tracks starlink satellite orbits via GPS, so that may limit their use as a redundant GPS system. Now I'm curious what their command and control links look like. It's possible and perhaps likely that they can only communicate with any given satellite intermittently, as they fly overhead of ground stations.

They know the locations of their satellites extremely precisely, and they know the round-trip time from them to the dish. It basically is a positioning system on it's own.

sneak 5y ago

Sure, but to do this would require firmware support (due to the timing requirements) in the satellites themselves, I believe. I doubt that's happening right now.

Robotbeat 5y ago
As bitrates increase, time of flight becomes more and more of an important quantity. Also, it’s likely Starlink satellites will develop ability to do time of flight for military reasons, ie as a backup to GPS.
- KirillPanov 5y ago
  It's likely that is the real motivation for Starlink. Rural internet is just a bonus. Laundering the money through FCC RDOF was a stroke of genius; I tip my hat to whoever came up with that idea.
  - Robotbeat 5y ago
    That doesn't make any sense. There's WAY more money in commercial satellite internet than there is with niche US military contracts. I don't understand why people are so committed to assuming there's a nefarious "real motivation" behind Starlink. Global telecomms is on the order of $2 trillion in revenue per year and growing. The US military's GPS budget is about $1.5 billion. So we're talking about addressable markets 3 orders of magnitude different in size.
    - KirillPanov 5y ago
      Oh yeah, I'm sure this just for fun: https://www.mentalfloss.com/article/75874/us-navy-returns-teaching-officers-how-navigate-stars https://www.mentalfloss.com/article/75874/us-navy-returns-te...
- sgtnoodle 5y ago
  The satellites are presumably themselves beamforming their transmissions to the dish to a high angular precision. If the satellites know their attitude precisely via star tracking and IMU, then a single satellite could be enough to geo-locate a dish. I wouldn't be surprised if SpaceX tracks starlink satellite orbits via GPS, so that may limit their use as a redundant GPS system. Now I'm curious what their command and control links look like. It's possible and perhaps likely that they can only communicate with any given satellite intermittently, as they fly overhead of ground stations.