Snooping On Starlink With An RTL-SDR

With an ever-growing constellation of Starlink satellites whizzing around over our heads, you might be getting the urge to start experimenting with the high-speed internet service. But at $100 or more a month plus hardware, the barrier to entry is just a little daunting for a lot of us. No worries, though — if all you’re interested in is tracking [Elon]’s birds, it’s actually a pretty simple job.

Now, we’re not claiming that you’ll be able to connect to Starlink and get internet service with this setup, of course, and neither is the delightfully named [saveitforparts]. Instead, his setup just receives the beacon signals from Starlink satellites, which is pretty interesting all by itself. The hardware consists of his “Picorder” mobile device, which sports a Raspberry Pi, a small LCD screen, and a host of sensors, including an RTL-SDR dongle. To pick up the satellite beacons, he used a dirt-cheap universal Ku-band LNB, or low-noise block downconverter. They’re normally found at the focal point of a satellite TV dish, but in this case no dish is needed — just power it up with a power injector and point it to the sky. The signals show up on the Picorder’s display in waterfall mode; curiously, the waterfall traces look quite similar to the patterns the satellites make in the night sky, much to the consternation of astronomers.

Of course, you don’t have to have a Picorder to snoop in on Starlink — any laptop and SDR should work, despite [saveitforparts]’ trouble in doing so. You shouldn’t have much trouble replicating the results by following the video below, which also has a few tips on powering an LNB for portable operations.

[via RTL-SDR.com]

21 thoughts on “Snooping On Starlink With An RTL-SDR

  1. The Starlink Ku-Band beacon frequency is 11.325GHz so a 10GHz L.O. LNB or a 9.75GHz Universal LNB (22kHz Off for Low Band) would be ideal for this. I am surprised that a measurable signal can be obtained without the use of dish to focus the signal into the feed horn of the LNB.

      1. Hi, a GEO is at 36000 km altitude, a NGSO Starlink is roughly at 360 km, therefore a difference in ratio of 20 dB, I.e. propagation loss 40 dB less for GSO than a NGSO Starlink. A dish has around 24 dBi, resulting in a margin of 16 dB. Of course, the transmitting downlink power is lower at NGSO, but remains a lot dor a good reception without the dish.

        1. To fix what I said, the GSO loss due to propagation is higher with 40 dB in comparison with VLEO Starlink satellite. From here, the budget link is far better, allowing lower / no dishes and lower terminals (lower unlink transmission power) than in the case of GSO. Again of 24 dBi is one of the best for a GSO terminal, in fact is much lower. Therefore, the margin is better.

    1. $110 plus the $500 for the equipment. Well, worth it for me, compared to the $70 I paid AT&T for the promised 6 down .5 up DSL, with a 150G Datacap. Received mine in April 2022, preordered Feb. 8th 2021. My Starlink speed rivals the offered speed of the fiber that we have been promised for years.

      1. Same here. I had 3Mbps DSL from AT&T for 8 years. While I’m not getting the speeds anticipated from Starlink (around 50Mbps,) it still feels like I’m finally back out of the Stone Age!

  2. If those are signals from different satellites, why would the traces be parallel to each other? The Doppler shift for a low Earth orbit satellite changes non-linearly up and down as the satellite approaches the receiver and then flies away. And that would happen at different times for different satellites.

    I think the drift that we see here maybe dominated by the thermal drift of the local oscillator in the down-converter.

    1. Or maybe, there are frequency difference between the satellites that are received belonging to different planes or different angular positions in a specific plane of the constellation.

  3. I have a brand new unit still in the box. Iwas one of the original beta testers but quickly discovered I had too many trees and never used it. A couple weeks ago. When I tried to use it again, I discovered the software for the modem was so far put of date that it couldn’t be updated. Anyone looking for a new dish to replace a damaged one, I have one, just make me an offer.

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