[Starlink] Re: Starlink and Iran

[Frantisek Borsik <frantisek.borsik@gmail.com>]

Starlink Terminal GPS Spoofing/Jamming Detection in Iran:

https://github.com/narimangharib/starlink-iran-gps-spoofing/blob/main/starlink-iran.md


Shared on Twitter:
https://x.com/narimangharib/status/2011426151999193513
<https://x.com/narimangharib/status/2011426151999193513?s=46&t=cDwZQ2vjNXB5mf76dxo5Hw>



All the best,

Frank
Frantisek (Frank) Borsik

In loving memory of Dave Täht: 1965-2025
https://libreqos.io/2025/04/01/in-loving-memory-of-dave/


https://www.linkedin.com/in/frantisekborsik
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On Fri, 16 Jan 2026 at 5:18 AM, Ulrich Speidel via Starlink <
starlink@lists.bufferbloat.net> wrote:

> I suspect (and may be wrong there) it's not that the uplink beam is
> narrow: That would be hard to do with an antenna that's size limited by
> the need to keep it a consumer device that the customer can be expected
> to handle and install. Rather, I suspect that it's the compute overhead
> involved at the ground end when it comes to recalculating the correct
> phases for tracking the fast-moving satellite. Basically, if you had
> unlimited compute power at the Dishy, you could recompute the beam
> frequently enough to always keep the satellite at the centre of the
> beam. Instead, if you position the beam such that the satellite moves
> across it, you can wait with recomputation until the satellite is about
> to leave the beam. This means less computation, cheaper chips, and less
> power use.
>
> That all said, a 2 km deviation isn't what I had in mind with "precision
> location" - I was thinking more of the type of deviation seen when the
> US military still applied "selective availability" to the civilian
> signal, and positions tended to be a few dozen to maybe a couple of
> hundred metres out. The 2 km more than cover this - and your
> observations actually confirm that position accuracy down to a couple of
> metres isn't needed here.
>
> On 16/01/2026 10:47 am, Oleg Kutkov via Starlink wrote:
> > 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
> >>>
> --
> ****************************************************************
> Dr. Ulrich Speidel
>
> School of Computer Science
>
> Room 303S.594 (City Campus)
>
> The University of Auckland
> u.speidel@auckland.ac.nz
> http://www.cs.auckland.ac.nz/~ulrich/
> ****************************************************************
>
>
>
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