Scroll down to read this post.


Please consider supporting my work, as I take no advertisements nor accept any sponsors in order to keep the website clean, easy to read, and to avoid any accusations of conflict of interest. Your support leaves me entirely independent, able to say whatever I think while being free from censorship or reprisals.


You can support me either by giving a one-time contribution or a regular subscription. There are five ways of doing so:


1. Zelle: This is the only internet method that charges no fees. All you have to do is use the Zelle link at your internet bank and give my name and email address (zimmerman at nasw dot org). What you donate is what I get.


2. Patreon: Go to my website there and pick one of five monthly subscription amounts, or by making a one-time donation.

3. A Paypal Donation:

4. A Paypal subscription:

5. Donate by check, payable to Robert Zimmerman and mailed to
Behind The Black
c/o Robert Zimmerman
P.O.Box 1262
Cortaro, AZ 85652

Researchers figure out how to make the Starlink constellation a GPS-type constellation

Researchers working independent from SpaceX and without any of the company’s proprietary data, have found a way to turn the Starlink internet constellation — now about 3,000 satellites strong — into a method of pinpointing one’s location, thus making it an alternative to GPS-type satellites.

To be clear, no one is accessing Starlink user data here. The sync sequences are just strings of timings and other data that the machines use to stay in touch — the payload data is entirely separate.

In the paper, due to the fact that the signal was being targeted at an actual Starlink user terminal, the location had to be for that terminal too, and they were able to get it within 30 meters. Not better than GPS, obviously, but it could be quicker and eventually more accurate if SpaceX were to give the project its blessing.

A software update that slightly adjusts how the satellites send their signals and a bit of data on correcting for variance between their clocks, and Humphreys suggests Starlink transmissions could be used to locate oneself to within a meter.

You can read the paper here [pdf].

It seems a no-brainer that at some point SpaceX management will recognize the money they can make from this extra capability, and will figure out the best way to produce and sell handheld units. It also appears that there will be profit in allowing others to also tag on.

Genesis cover

On Christmas Eve 1968 three Americans became the first humans to visit another world. What they did to celebrate was unexpected and profound, and will be remembered throughout all human history. Genesis: the Story of Apollo 8, Robert Zimmerman's classic history of humanity's first journey to another world, tells that story, and it is now available as both an ebook and an audiobook, both with a foreword by Valerie Anders and a new introduction by Robert Zimmerman.

The ebook is available everywhere for $5.99 (before discount) at amazon, or direct from my ebook publisher, ebookit. If you buy it from ebookit you don't support the big tech companies and the author gets a bigger cut much sooner.

The audiobook is also available at all these vendors, and is also free with a 30-day trial membership to Audible.

"Not simply about one mission, [Genesis] is also the history of America's quest for the moon... Zimmerman has done a masterful job of tying disparate events together into a solid account of one of America's greatest human triumphs."--San Antonio Express-News


  • John

    Interesting, but I don’t see how SpaceX can market and make money off this. They would have to do location better and cheaper than GPS, Glonass, and Galileo.

    One possibility might be a military application – could this potentially be used in a GPS denied environment?

  • Ray Van Dune

    “…could this potentially be used in a GPS denied environment?”
    I think it certainly could, and one of the strengths of such a solution might well be that, not being a bespoke GPS, it presumably would require other than standard anti-GPS techniques to defeat it.

    It might also be “dumber” than purpose-built GPS systems, and/or with less intelligence vulnerable in space, and more on the ground.

  • pzatchok

    Starlink is trying to make a partnership with a phone company.

    If it turns out it is possible to send and receive at least text messages directly through the satellites then this could also be used as an emergency geo locator for hikers and backpackers lost in the woods.

    Years ago when bluetooth was new I heard about an app that would sent text messages by bluetooth. This was an attempt to keep communications going even if the grid and the towers went down. The limit the functionality of the app was the amount of memory in each phone. Now though the amount of memory is huge and even in someplace like New York each phone would not get filled up.

  • LocalFluff

    The hurdle is the receivers, getting such chips into smart phones. As 5G network infrastructure is being built, so is UWB, Ultra Wide Band. UWB radio chips are also already in all new iPhones and at least some Samsung. models. UWB means transmitting across a very wide band of radio frequencies at once. This allows for signals to pass through obstacles like concrete walls and human bodies. Thus allowing for determining location by triangulation, measuring the time of travel for the radio signals from multiple fixed installed (in 5G cell stations for example) and so the distance to each of them. The precision can be much better than with GPS, better than centimeter, depending on how dense the stationary radio beacon network is.

    Verizon seems to be leading the way by installing UWB where they install 5G in most US cities. And most new phones can use it. The applications are however still very poorly developed. There’s a big potential for new business here. Lots and lots of application for business to keep track of things that move indoors. There are of course cheap UWB microchips available, no need for an expensive smartphone other than for consumer convenience. There are also cheap USB dongles with UWB transmitters that can easily be installed on computers for the one who would like to try it on at home. Keeping track of the cat or something, the applications do need some imagination, but there certainly are plenty.

Readers: the rules for commenting!


No registration is required. I welcome all opinions, even those that strongly criticize my commentary.


However, name-calling and obscenities will not be tolerated. First time offenders who are new to the site will be warned. Second time offenders or first time offenders who have been here awhile will be suspended for a week. After that, I will ban you. Period.


Note also that first time commenters as well as any comment with more than one link will be placed in moderation for my approval. Be patient, I will get to it.

Leave a Reply

Your email address will not be published. Required fields are marked *