From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from oxalide-smtp-out.extra.cea.fr (oxalide-smtp-out.extra.cea.fr [132.168.224.13]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by lists.bufferbloat.net (Postfix) with ESMTPS id 438F73B29D for ; Thu, 14 Sep 2023 05:14:17 -0400 (EDT) Received: from pisaure.intra.cea.fr (pisaure.intra.cea.fr [132.166.88.21]) by oxalide-sys.extra.cea.fr (8.14.7/8.14.7/CEAnet-Internet-out-4.0) with ESMTP id 38E9EFht060064 for ; Thu, 14 Sep 2023 11:14:15 +0200 Received: from pisaure.intra.cea.fr (localhost [127.0.0.1]) by localhost (Postfix) with SMTP id BE3742054EC for ; Thu, 14 Sep 2023 11:14:15 +0200 (CEST) Received: from muguet1-smtp-out.intra.cea.fr (muguet1-smtp-out.intra.cea.fr [132.166.192.12]) by pisaure.intra.cea.fr (Postfix) with ESMTP id B26532054D7 for ; Thu, 14 Sep 2023 11:14:15 +0200 (CEST) Received: from [10.8.32.70] (is156570.intra.cea.fr [10.8.32.70]) by muguet1-sys.intra.cea.fr (8.14.7/8.14.7/CEAnet-Internet-out-4.0) with ESMTP id 38E9EFLR039447 for ; Thu, 14 Sep 2023 11:14:15 +0200 Message-ID: Date: Thu, 14 Sep 2023 11:14:15 +0200 MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Content-Language: fr To: starlink@lists.bufferbloat.net References: From: Alexandre Petrescu In-Reply-To: Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 8bit Subject: Re: [Starlink] Starlink Reverse Engineering X-BeenThere: starlink@lists.bufferbloat.net X-Mailman-Version: 2.1.20 Precedence: list List-Id: "Starlink has bufferbloat. Bad." List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Thu, 14 Sep 2023 09:14:17 -0000 Le 08/09/2023 à 16:27, Hesham ElBakoury via Starlink a écrit : > This MIT Technology Review report provides the details of the work > done by Professor Humphrey and his team to reverse engineer starlink > signals: > https://www.google.com/amp/s/www.technologyreview.com/2022/10/21/1062001/spacex-starlink-signals-reverse-engineered-gps/amp/ Thanks for the pointer.  I have not read it. But, I would challenge the concept of reverse engineering there to say that one might not need to reverse engineer at very low level to achieve that effect. In a WiFi and GSM setting (not starlink), people do not reverse engineer it too much to make localisation out of wifi beacons and GSM cell info.  Just like starlink, WiFi and GSM were not designed to do localisation, yet the current smartphone localisation info ('where am I') is relying extensively on GSM, WiFi, bluetooth and other non GPS signals.  I suspect it relies on these even more than on signals that were designed to do localisation like the Galileo and other countries signals. In the future, with this constant increase of starlink availability, it might be possible to add starlink as an additional source of time and localisation (in addition to GSM, WiFi etc) without any reverse engineering.  Just listen to the signals (if they are not crypted, I dont know) and derive some info from there. The position of the starlink sats themselves is public info.  So, it is very possible to derive a more precise the position ('where am I') from the sats that I receive, and knowing which sats are currently in view at my approximate location.  Probably there are already some smartphone apps that show that somehow. The interesting thing would be the other way around: non-starlink sats listen to starlink signals emitted by ground user antennas and tell where these users are.   Even that would not require very deep reverse engineering, but the achieved effect could be very effective.  Of course, it depends how it is used, for which purpose. Alex > > It is worth it to mention that Elon Musk does not like using starlink > for navigation which is the motivation behind Humphrey > > Although the report mentions Humphrey non-peer reviewed paper, > actually the peer-reviewed paper has been published here > https://ieeexplore.ieee.org/abstract/document/10107477?casa_token=ws8yh0wRnRsAAAAhA:Q0LZ3Gt-vxKsGQ170OhIp4X4tQoa_U2m6DlBKY7a-A0EYxTzRd4VLzpHkZKSglEPiMEJKK4XTHk > > Hesham > > _______________________________________________ > Starlink mailing list > Starlink@lists.bufferbloat.net > https://lists.bufferbloat.net/listinfo/starlink