Cell Towers Can Double as Cheap Radar Systems for Ports and Harbors (2014)

https://spectrum.ieee.org/cell-tower-signals-can-improve-port-security

43•transpute•5h ago

Comments

timewizard•5h ago

No? It's significantly smarter and easier to use AIS.

zomiaen•4h ago

From the first paragraph: "Without radar installations, it can be hard for port employees to detect small ships like those employed by pirates or by the terrorists who attacked the USS Cole in 2000"

I don't think this is intended to track the type of folks who leave their AIS broadcasting.

jchulce•4h ago

AIS, like ADSB, is secondary surveillance - not radar. It's a mechanism for cooperative targets with functioning electronics to identify themselves and provide operational information. However, it does not detect uncooperative entities or those not equipped with the electric transponders. For example, AIS won't show you an enemy's invading fleet, and ADSB won't show incoming missiles. Those needs are fulfilled by primary surveillance radar, like the passive solution from this article.

timewizard•47m ago

If you're honestly worried about being bombed then you need to buy radar.

With your logic all I have to do is take the additional step of disabling your cellular infrastructure before I steam up to your port.

This is not a tactical solution. It can only be for convenience or cost savings. In that realm, AIS is the obvious answer.

timschmidt•37m ago

It can also be used for defense in depth. Each additional sensing system which must be disabled before an attack is an additional barrier.

ImPostingOnHN•4h ago

I spoke with a startup that is using 5G cell towers as radar. They said it is high-enough resolution to perform gait recognition.

userbinator•4h ago

The 5G conspiracy theorists are paying attention.

toomuchtodo•3h ago

Depending on node density of a 5G network (think street lamp cells), it is not outside of the realm of possibility that you're going to be able to obtain radar derived point clouds from cellular networks doing double duty as phased array radar networks. Greater density = greater observability and surveillance capabilities through SDR (limited by hardware frequency band operating tolerances).

https://electronics360.globalspec.com/article/14127/micro-5g...

bee_rider•4h ago

Hmm. I wonder how big a different the whole 24Ghz vs 6Ghz thing makes, when used as a radar.

polalavik•4h ago

There's a whole host of radar research using OFDM/ Wifi (I wrote a paper on the topic a while back where i implemented it with some software defined radios).

The best paper on the topic is Martin Brauns[1]. It's insanely comprehensive and easy to digest.

[1] https://publikationen.bibliothek.kit.edu/1000038892/2987095

stefan_•3h ago

Doesn't the thesis assume you are the one sending out the OFDM signal, while the OP is about a passive radar thing? Maybe I got one of those mixed up.

makeitdouble•4h ago

To properly understand, how much resolution is needed for that ?

supportengineer•2h ago

I seem to recall reading (on HN, no less) that advanced passive radar technology is classified as munitions, by the US Government and is under export controls?

syedkarim•2h ago

Yes, they are on the BIS Commerce Control List. It doesn't need to be particularly advanced to be export controlled.

5A001.g Passive Coherent Location (PCL) systems or equipment, “specially designed” for detecting and tracking moving objects by measuring reflections of ambient radio frequency emissions, supplied by non-radar transmitters. Technical Note: For the purposes of 5A001.g, non-radar transmitters may include commercial radio, television or cellular telecommunications base stations.

https://www.bis.doc.gov/index.php/documents/regulations-docs...

charcircuit•1h ago

You are probably thinking of this thread:

https://news.ycombinator.com/item?id=33581696

gene-h•1h ago

There are proposals for the 6G standard to support Integrated Sensing and Communication(ISAC)[0]. So the hardware might natively be able to support gait recognition. The use cases given are UAV detection and localization. It sort of seems like this could bring Vernor Vinge's localizer mesh to reality, privacy implications be damned [0]https://www.ericsson.com/en/blog/2024/6/integrated-sensing-a...

nelox•4h ago

Also flood forecasting

https://www.smh.com.au/national/nsw/world-first-5g-spy-will-...

toomuchtodo•3h ago

https://archive.today/krT4z

westurner•2h ago

Flood sensing with 5G?

> [...] New South Wales State Emergency Service (NSW SES) and the NSW Government, University of Technology Sydney (UTS) researchers working with industry partner TPG Telecom [...]

> “We want to tell people exactly how high [the flood] is. We’re now down to accuracy of 0.1 metres.”

> [...] “Currently, residents will receive the warning that the water is going to come, and they’ve got to get their cattle to higher ground. But how high is high?” she said.

ofalkaed•3h ago

With how cheap radar has gotten in the past decade I would be curious to know if any ports/harbors actually use cell towers?

transpute•3h ago

More coverage of RF sensing, including laptops/phones with radios+NPU to sense their human:

2025, "Espargos: ESP32-based WiFi sensing array", 30 comments, https://news.ycombinator.com/item?id=43079023

2024, "How Wi-Fi sensing became usable to track people's movements", https://www.technologyreview.com/2024/02/27/1088154/wifi-sen...

2023, "What Is mmWave Radar?: Everything You Need to Know About FMCW", 30 comments, https://news.ycombinator.com/item?id=35312351

2022, "mmWave radar, you won't see it coming", 180 comments, https://news.ycombinator.com/item?id=30172647

2021, "The next big Wi-Fi standard is for sensing, not communication", 200 comments, https://news.ycombinator.com/item?id=29901587

soundpuppy•3h ago

The gap between the people demanding these systems and those who design it it is so large, it’s vulnerable to corruption in infinite ways, let’s be honest.

knetl•1h ago

It underscores how important cybersecurity is in mobile, IoT and Wi-Fi systems. A few critical exploits chained together is all it takes for physical surveillance or bio-sensing[1].

A 2007 NSA hacking toolkit catalog leaked by Snowden[2] shows what state-of-the-art was 18 years ago. Just imagine what a remote attacker can do with today's commercial hardware.

[1]https://www.mdpi.com/1424-8220/24/7/2111

[2]https://www.eff.org/document/20131230-appelbaum-nsa-ant-cata...

blendo•32m ago

I wouldn't go so far as to call this RF "pollution", but it is a reminder that the EM spectrum is getting a lot busier.

Me? I just want a car to be able to detect me so they don't run me over.

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