4 ms·

Is it actually legal to build radars?

by Thaxll 4y ago

H8crilA 4y ago
It is legal to receive and process almost any electromagnetic radiation, yes. Transmission is licensed for nearly anything slightly below infrared, mostly because it would become a mess if everyone transmitted whatever they felt like. It is also restricted above UV, but for other reasons :)
- heavenlyblue 4y ago
  It's not legal in the UK
  - ricktdotorg 4y ago
    as a UK person living in the US who recently passed the US (technician) Ham radio exam, it astonishes me how draconian the UK laws are about RF. it's even illegal to listen to UK air traffic control radio? what? how can they even be serious
    - bheadmaster 4y ago
      > it's even illegal to listen to UK air traffic control radio How exactly would they know that you're listening?
      - isthisnametaken 4y ago
        Generally, they don't, and no-one cares. Airband scanners are freely available to buy online and in shops. It really manifests itself when you look online to see "listen to ATC" live streams and YouTube videos. There aren't any from the UK. https://www.liveatc.net/faq/ https://www.liveatc.net/faq/
ilc 4y ago
You can receive anything... sending is another issue. This is discussing passive radar, where you use another emitter, like a FM station or 20 to be transmitters, and your "radar" just sits and listens for the bounces off other objects.
- thenthenthen 4y ago
  This is definitely not true for every legislation.
  - IrishJourno 4y ago
    Yes, the United States has a you-can-recieve-anything philosophy (with some limits for old analog cellphone frequencies, and restrictions on using, e.g. a police scanner in a car) that isn't matched in many other countries, which is the legal basis of how Ireland and the U.K. require you to buy a license to watch over-the-air television.
    - secondcoming 4y ago
      The TV licence has been expanded to include any live broadcast, so watching sport on Amazon requires a TV licence. I also think that in the UK it’s illegal to listen to ATC.
      - edrxty 4y ago
        How did the UK ever get to be this way?
        H8crilA 4y ago
        Centuries of legal scar tissue accumulated through continuous, unbroken political order.
  - coretx 4y ago
    Treaty of Rome. Maybe North-Korea did not sign it but that is nitpicking.
CamperBob2 4y ago
Arguably everyone in the US who owns or constructs an SDR is a felon, by virtue of violating the Electronic Communications Privacy Act of 1986 [1,2]. Certainly everyone who sells one. AFAIK this misguided law has never been repealed, despite being rendered obsolete by the demise of the old 800 MHz AMPS standard. No 800 MHz-capable SDRs I'm aware of make even the most casual attempt at blocking coverage of that range. So, yes, it's legal to build a radar -- certainly a passive one -- but given that most SDRs cover the ECPA-prohibited frequency range, it would be hard to build a radar with off-the-shelf equipment without breaking other laws. 1: https://en.wikipedia.org/wiki/Electronic_Communications_Privacy_Act https://en.wikipedia.org/wiki/Electronic_Communications_Priv... 2: https://forums.radioreference.com/threads/cellular-blocked-scanners.292708/ https://forums.radioreference.com/threads/cellular-blocked-s...
- wolfendin 4y ago
  The ECPA makes it illegal to eavesdrop on all phone calls, it’s the 1992 amendment to the Federal Communications Act of 1934 that allows the FCC to restrict the part 15 authorization of anything that can receive cellular calls: https://www.govinfo.gov/content/pkg/STATUTE-106/pdf/STATUTE-106-Pg4181.pdf#page=15 https://www.govinfo.gov/content/pkg/STATUTE-106/pdf/STATUTE-... SEC. 403. INTERCEPTION OF CELLULAR TELECOMMUNICATIONS. […] “(d)(1) Within 180 days after the date of enactment of this subsection, the Commission shall prescribe and make effective regulations denying equipment authorization (under part 15 of title 47, Code of Federal Regulations, or any other part of that title) for any scanning receiver that is capable of— "(A) receiving transmissions in the frequencies allocated to the domestic cellular radio telecommunications service, "(B) readily being altered by the user to receive trans- missions in such frequencies, or “(C) being equipped with decoders that convert digital cellular transmissions to analog voice audio.
  - RF_Savage 4y ago
    Which is why wideband SDR's like hackRF are licenced as laboratory equipment. So the regulatory regime is the one for spectrum analyzers and signal generators. I have always wondered if people in the old days used the FM demodulation option to listen in on phone calls.

Is it actually legal to build radars?

by Thaxll 4y ago

Is it actually legal to build radars?

It is legal to receive and process almost any electromagnetic radiation, yes. Transmission is licensed for nearly anything slightly below infrared, mostly because it would become a mess if everyone transmitted whatever they felt like. It is also restricted above UV, but for other reasons :)

heavenlyblue 4y ago
It's not legal in the UK
- ricktdotorg 4y ago
  as a UK person living in the US who recently passed the US (technician) Ham radio exam, it astonishes me how draconian the UK laws are about RF. it's even illegal to listen to UK air traffic control radio? what? how can they even be serious
  - bheadmaster 4y ago
    > it's even illegal to listen to UK air traffic control radio How exactly would they know that you're listening?
    - isthisnametaken 4y ago
      Generally, they don't, and no-one cares. Airband scanners are freely available to buy online and in shops. It really manifests itself when you look online to see "listen to ATC" live streams and YouTube videos. There aren't any from the UK. https://www.liveatc.net/faq/ https://www.liveatc.net/faq/

ilc 4y ago

You can receive anything... sending is another issue. This is discussing passive radar, where you use another emitter, like a FM station or 20 to be transmitters, and your "radar" just sits and listens for the bounces off other objects.

thenthenthen 4y ago
This is definitely not true for every legislation.
- IrishJourno 4y ago
  Yes, the United States has a you-can-recieve-anything philosophy (with some limits for old analog cellphone frequencies, and restrictions on using, e.g. a police scanner in a car) that isn't matched in many other countries, which is the legal basis of how Ireland and the U.K. require you to buy a license to watch over-the-air television.
  - secondcoming 4y ago
    The TV licence has been expanded to include any live broadcast, so watching sport on Amazon requires a TV licence. I also think that in the UK it’s illegal to listen to ATC.
    - edrxty 4y ago
      How did the UK ever get to be this way?
      - H8crilA 4y ago
        Centuries of legal scar tissue accumulated through continuous, unbroken political order.
- coretx 4y ago
  Treaty of Rome. Maybe North-Korea did not sign it but that is nitpicking.

CamperBob2 4y ago

Arguably everyone in the US who owns or constructs an SDR is a felon, by virtue of violating the Electronic Communications Privacy Act of 1986 [1,2]. Certainly everyone who sells one. AFAIK this misguided law has never been repealed, despite being rendered obsolete by the demise of the old 800 MHz AMPS standard. No 800 MHz-capable SDRs I'm aware of make even the most casual attempt at blocking coverage of that range. So, yes, it's legal to build a radar -- certainly a passive one -- but given that most SDRs cover the ECPA-prohibited frequency range, it would be hard to build a radar with off-the-shelf equipment without breaking other laws. 1: https://en.wikipedia.org/wiki/Electronic_Communications_Privacy_Act https://en.wikipedia.org/wiki/Electronic_Communications_Priv... 2: https://forums.radioreference.com/threads/cellular-blocked-scanners.292708/ https://forums.radioreference.com/threads/cellular-blocked-s...

wolfendin 4y ago
The ECPA makes it illegal to eavesdrop on all phone calls, it’s the 1992 amendment to the Federal Communications Act of 1934 that allows the FCC to restrict the part 15 authorization of anything that can receive cellular calls: https://www.govinfo.gov/content/pkg/STATUTE-106/pdf/STATUTE-106-Pg4181.pdf#page=15 https://www.govinfo.gov/content/pkg/STATUTE-106/pdf/STATUTE-... SEC. 403. INTERCEPTION OF CELLULAR TELECOMMUNICATIONS. […] “(d)(1) Within 180 days after the date of enactment of this subsection, the Commission shall prescribe and make effective regulations denying equipment authorization (under part 15 of title 47, Code of Federal Regulations, or any other part of that title) for any scanning receiver that is capable of— "(A) receiving transmissions in the frequencies allocated to the domestic cellular radio telecommunications service, "(B) readily being altered by the user to receive trans- missions in such frequencies, or “(C) being equipped with decoders that convert digital cellular transmissions to analog voice audio.
- RF_Savage 4y ago
  Which is why wideband SDR's like hackRF are licenced as laboratory equipment. So the regulatory regime is the one for spectrum analyzers and signal generators. I have always wondered if people in the old days used the FM demodulation option to listen in on phone calls.