[Starlink] Re: Starlink and Iran

[Ulrich Speidel <u.speidel@auckland.ac.nz>]

On 18/01/2026 7:32 am, Michael Richardson wrote:
> --------
>
> Ulrich Speidel <u.speidel@auckland.ac.nz> wrote:
>      >> 1. Who checks/enforces this ITU limit?
>
>      > The licensing authorities in the respective countries (i.e., the FCC in the
>      > US - and they're held to account by their competitors, of which SpaceX has a
>      > few in the US). At an international level, if one country were to
>      > ignore
>
> Yes, but dieselgate.  Obey, except when it is important not to.
Except that if you ignore this in orbit, you'd find that you have to put 
up with interference from others' systems, too, who will now see your 
breach of the rules as license to do this for you.
>
>      >> 2. Could the physically satellites go higher over some territory? How much higher?
>      >> I assume it's software controlled.
>
>      > A satellite has three types of energy that determine its orbital motion:
>      > Potential energy from orbital height, kinetic energy from moving, and
>      > energy
>
> Sorry, you mis-understood, or I mis-typed, I now understand.
> I meant, go to a higher-power.  Not a higher orbit :-)

I'd misunderstood you there indeed. The answer is "no, but ...". I 
gather that the transmitters on Starlink satellites are all DSP based, 
and given that they were probably designed for the original limits that 
SpaceX had promised to adhere to, I'd say it's likely that this won't be 
possible with most of the current fleet - their maximum EIRP is well 
documented and you don't design a transmitter to be more powerful than 
it needs to be, especially when it has to go into space, as this just 
adds weight (and probably reduces demisability). So that would have to 
be done via redesign and orbit re-stocking rather than just flicking a 
switch. But: With DSP, you get to choose which part of the spectrum you 
put your EIRP into ... and if you shrink that (sub-)band, then yes you 
presumably could project higher power flux density even from the 
existing birds - at a bit of a cost in terms of capacity. But given the 
relatively low number of Dishys in Iran, that probably wouldn't be much 
of an issue. But it would change what your Dishy needs to look for in 
terms of beam signal structure, and that might be less trivial to handle.

Plus it doesn't do anything if the positioning is out by many many 
miles, which seems to be the aim with the GPS spoofing / jamming attacks 
in Iran.

> ----
>
> (Has anyone proposed eliptical orbits for LEOs or MEOs, such that they would
> be lower whenever they are over the service territory, and higher otherwise.
> I imagine it would be horribly complex to work out, given various
> precessions, and it's not clear to me why.  I think because less drag when
> not low down...)

That's historically been done for polar sites, albeit in such a way that 
the satellite would be high above the poles (to maximise time in view) 
and low around the Equator. And that wasn't LEO. The biggest problem 
with doing this in LEO space is that the satellite is fastest when it's 
closest to Earth, and drag is proportional to the square of the speed, 
so such an orbit would require a lot of fuel to maintain.

-- 
****************************************************************
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/
****************************************************************