[Starlink] Re: Starlink and Iran

Oleg Kutkov
2026-01-15T21:47:45Z

Actually, a precise location is required to calculate the uplink beam.
For the downlink, it's not so critical (at least for the initial
sky_search procedure), since the satellite beam covers the whole cell.
But the uplink beam is quite narrow, and the terminal needs to pinpoint
the moving satellite.
From my experiments, shifting the GPS data for more than 2km breaks the
math and disrupts the connection. With an incorrect position, Starlink
is stuck in NO_SCHEDULE mode.

On 1/15/26 22:07, Ulrich Speidel via Starlink wrote:
> Military-grade GPS kind of lost its exclusivity a long time ago when
> people came up with DGPS (differential GPS), where a local reference
> station with known position transmits a "delta" signal to the GPS
> signal received at that location. And then of course came GLONASS &
> Co., so there's currently about four GPS-like systems out there, and
> most modern receivers support all. That said - these signals can all
> be interfered with and spoofed.
>
> For Starlink, precision location isn't actually required (it's enough
> for Dishy to know which cell it's in because that determines the
> beams).  But GPS receiver chips are cheap and extra position accuracy
> doesn't do any harm.
>
> On 16/01/2026 6:10 am, J Pan wrote:
>> easier to attack gps?
>> https://github.com/narimangharib/starlink-iran-gps-spoofing/blob/main/starlink-iran.md
>>
>> although not all technically correct. "inhibitGps" is a user choice
>> through the mobile app ("Use Starlink positioning exclusively") not
>> system determination, but gps spoofing is indeed there. starlink could
>> be authorized to decode military-grade gps signals as well?
>> --
>> J Pan, UVic CSc, ECS566, 250-472-5796 (NO VM), Pan@UVic.CA,
>> Web.UVic.CA/~pan
>>
--
Best regards,
Oleg Kutkov