31 ms·

WWV, WWVH, and WWVB are more than charity for timekeepers. They distribute time and frequency, traceable to a national standard, for one leg of "positioning, n

WWV, WWVH, and WWVB are more than charity for timekeepers. They distribute time and frequency, traceable to a national standard, for one leg of "positioning, navigation, and timing." Before GPS and the internet, numerous services depended on those signals. I would argue that now, we have positioning, navigation, and timing from multiple satellite systems (and a phone network providing excellent time & freq references derived from satellites). We have internet time synced to atomic standards and satnav. All of the modern references are more precise, accurate, and stable than WWV, WWVH, and WWVB. As to devices which sync from WWVB, there are gadgets which can get GPS time and transmit an LF signal for syncing those devices. No problems, ladies and gents, you've still got time.

saagarjha 8y ago
The services you described as being dependent on these stations cannot necessarily be upgraded to use internet or satellite time.
- nutcracker46 8y ago
  There may be an interesting market not only for simulated WWVB but WWV / WWVH if someone absolutely needs to sync from HF. Those HF signals are notoriously unstable in phase, so a locally simulated signal may actually be better. Here's an example of work on simulating WWVB, not yet in mass production: https://sites.google.com/site/wayneholder/controlling-time https://sites.google.com/site/wayneholder/controlling-time. He could use a precision frequency source if a precise 60 kHz was absolutely necessary.
  - casylum 8y ago
    It's not the phase stability that's important, but the accuracy and drift over time.
  - saagarjha 8y ago
    I’m not sure what you mean by “locally simulated”. If I need to run this in my house, I now need to deal with a new device when my wall clock would have continued to work by itself before. If this needs to be done at the city level, then I now need to depend on someone providing a municipal service that needs to work consistently and reliably, which I am less confident that a city can run over the federal government (though, considering this incident, maybe I’m misguided?)
    - GlenTheMachine 8y ago
      There’s also the licensing issue. You can’t just start broadcasting on that frequency. The FCC would have to assign it to you, or start up a licensing scheme.
      - mark-r 8y ago
        If the lawmakers were smart, they would make an explicit allowance for micropower transmitters on those frequencies in perpetuity. I wouldn't get my hopes up though.
Spooky23 8y ago
The Russians still equip their navy with shortwave. There’s a reason for that. In any sort of conflict, GPS will be gone in hours.
- m0zg 8y ago
  Shortwave will also be gone, probably even sooner because it's not as directional. It's safe to assume that all of the electronic bullshit everyone is building into their "weapons systems" will be the first thing to be disrupted. I hope the military trains without it as well, because if not, it's only good against some illiterate mujahedeen with kalashnikovs, not against any kind of sophisticated adversary.
  - pps43 8y ago
    It's a lot more difficult to jam short wave than GPS because of multipath propagation. The Soviets routinely jammed Radio Free Europe / Radio Liberty yet it was still possible to listen to it. The navy doesn't have to be on the fixed frequency, so jamming it is going to be even harder.
    - m0zg 8y ago
      Radioelectronic warfare has come a long way since then. Russian Air Force was able to successfully disrupt both the communications and AEGIS on USS Donald Cook in the Black Sea with just one fairly lightweight and otherwise unarmed Su-24 plane outfitted with their current suppressive gear. Pentagon of course denies this happened, but Donald Cook left the Black Sea in a hurry after that. Likewise, the deployment of electronic countermeasures in Syria impeded US attacks on Syrian Government forces several times: https://www.armyrecognition.com/october_2018_global_defense_security_army_news_industry/russia_deploys_electronic_warfare_in_syria.html https://www.armyrecognition.com/october_2018_global_defense_... Jamming of shortwave was only partially effective in the USSR for several reasons: 1. They didn't want to jam _all_ shortwave broadcasts. 2. The receiver was very far away, far beyond where the receiver would be in a typical battlefield situation. By definition, if the disruptor is able to saturate the frequency band of the transmitter with a comparable amount of energy, multipath transmission won't help. And if the signal is wide band enough, frequency hopping won't help either.
zamadatix 8y ago
Do any of these satellite systems work inside a building without running antennae to the roof?
- nutcracker46 8y ago
  Window antennas work fairly well, but a roof mounted antenna / preamp is far more reliable.
nutcracker46 8y ago
Local service for houses or buildings could be provided service with limited power signals under rules for low power devices / FCC Part 15. Yes, you would need hardware to get your satnav (or mobile phone) signals and create the replacements for your LF/MF/HF dependent devices. You have to ask yourself, "Where is the point of diminishing returns in retaining dependency on signals like WWV / WWVH?" By the way eLoran will probably be the terrestrial back up for GNSS based position / navigation / timing. Also, if we get to the geopolitical state of satellites being destroyed, there will be a truckload of larger problems to worry about. Any nation with the hubris to destroy GNSS birds deserves the nukes they suffer in return. Any nation who lets it happen, because the leader is numbnutted, deserves to suffer a breakdown for not being more mature in managing its geopolitical situation. Fifth Risk indeed.
- tjohns 8y ago
  Is eLORAN still actually happening in the US? Since we shut down our LORAN transmitters a few years ago, I assumed the plans for eLORAN went out the window with it.
  - FlyMoreRockets 8y ago
    AFIK, everything is going to GPS and ADS-B.
SomeHacker44 8y ago
I would buy one in a heartbeat if true. I moved and neither of my watches (one Citizen and one Seiko) can get the Colorado signal anymore from the Northeast USA. But as other posters point out, I cannot imagine the FCC would allow those devices. But, OTOH, the propagation characteristics of any small device/antenna running at 60kHz would be abysmally bad and perhaps unworthy of notice. I would still not bet my several FCC licenses on it though.
anishathalye 8y ago
I made one of these GPS -> WWVB simulators a couple years ago. There's a short write-up here, in case anyone is interested in reading about it: https://www.anishathalye.com/2016/12/26/micro-wwvb/ https://www.anishathalye.com/2016/12/26/micro-wwvb/ There are also some neat iPhone apps that use the audio circuitry to produce a low-power signal that can be picked up by radio-controlled clocks that are close by: https://itunes.apple.com/us/app/clock-wave/id1073576068?mt=8 https://itunes.apple.com/us/app/clock-wave/id1073576068?mt=8 A couple people mentioned the FCC and licensing issues in the comments below. As far as I know, as long as you're transmitting at a very low power (40 µV/m as measured at 300m), it's okay. This should be fine for personal use, but won't work on a municipal level.
- xiii1408 8y ago
  Dude! That's freaking awesome. I've been wanting to set up a GPS-based NTP server for a while, but haven't gotten around to it yet. I'll have to read through and take a look at the transmitting equipment you used; adding WWVB to it would be awesomesauce.
- escherplex 8y ago
  Not bad! While reading the article the thought occurred that if WWV were eliminated then this would be a good opportunity for a smart phone app to pipe a GPS derived time standard emulating WWV format into a < 100mw (Part 15) 5, 10, or 15 MHz attached transmitter. And the idea was already objectified.

saagarjha 8y ago

The services you described as being dependent on these stations cannot necessarily be upgraded to use internet or satellite time.

nutcracker46 8y ago
There may be an interesting market not only for simulated WWVB but WWV / WWVH if someone absolutely needs to sync from HF. Those HF signals are notoriously unstable in phase, so a locally simulated signal may actually be better. Here's an example of work on simulating WWVB, not yet in mass production: https://sites.google.com/site/wayneholder/controlling-time https://sites.google.com/site/wayneholder/controlling-time. He could use a precision frequency source if a precise 60 kHz was absolutely necessary.
- casylum 8y ago
  It's not the phase stability that's important, but the accuracy and drift over time.
- saagarjha 8y ago
  I’m not sure what you mean by “locally simulated”. If I need to run this in my house, I now need to deal with a new device when my wall clock would have continued to work by itself before. If this needs to be done at the city level, then I now need to depend on someone providing a municipal service that needs to work consistently and reliably, which I am less confident that a city can run over the federal government (though, considering this incident, maybe I’m misguided?)
  - GlenTheMachine 8y ago
    There’s also the licensing issue. You can’t just start broadcasting on that frequency. The FCC would have to assign it to you, or start up a licensing scheme.
    - mark-r 8y ago
      If the lawmakers were smart, they would make an explicit allowance for micropower transmitters on those frequencies in perpetuity. I wouldn't get my hopes up though.

Spooky23 8y ago

The Russians still equip their navy with shortwave. There’s a reason for that. In any sort of conflict, GPS will be gone in hours.

m0zg 8y ago
Shortwave will also be gone, probably even sooner because it's not as directional. It's safe to assume that all of the electronic bullshit everyone is building into their "weapons systems" will be the first thing to be disrupted. I hope the military trains without it as well, because if not, it's only good against some illiterate mujahedeen with kalashnikovs, not against any kind of sophisticated adversary.
- pps43 8y ago
  It's a lot more difficult to jam short wave than GPS because of multipath propagation. The Soviets routinely jammed Radio Free Europe / Radio Liberty yet it was still possible to listen to it. The navy doesn't have to be on the fixed frequency, so jamming it is going to be even harder.
  - m0zg 8y ago
    Radioelectronic warfare has come a long way since then. Russian Air Force was able to successfully disrupt both the communications and AEGIS on USS Donald Cook in the Black Sea with just one fairly lightweight and otherwise unarmed Su-24 plane outfitted with their current suppressive gear. Pentagon of course denies this happened, but Donald Cook left the Black Sea in a hurry after that. Likewise, the deployment of electronic countermeasures in Syria impeded US attacks on Syrian Government forces several times: https://www.armyrecognition.com/october_2018_global_defense_security_army_news_industry/russia_deploys_electronic_warfare_in_syria.html https://www.armyrecognition.com/october_2018_global_defense_... Jamming of shortwave was only partially effective in the USSR for several reasons: 1. They didn't want to jam _all_ shortwave broadcasts. 2. The receiver was very far away, far beyond where the receiver would be in a typical battlefield situation. By definition, if the disruptor is able to saturate the frequency band of the transmitter with a comparable amount of energy, multipath transmission won't help. And if the signal is wide band enough, frequency hopping won't help either.

zamadatix 8y ago

Do any of these satellite systems work inside a building without running antennae to the roof?

nutcracker46 8y ago
Window antennas work fairly well, but a roof mounted antenna / preamp is far more reliable.

nutcracker46 8y ago

Local service for houses or buildings could be provided service with limited power signals under rules for low power devices / FCC Part 15. Yes, you would need hardware to get your satnav (or mobile phone) signals and create the replacements for your LF/MF/HF dependent devices. You have to ask yourself, "Where is the point of diminishing returns in retaining dependency on signals like WWV / WWVH?" By the way eLoran will probably be the terrestrial back up for GNSS based position / navigation / timing. Also, if we get to the geopolitical state of satellites being destroyed, there will be a truckload of larger problems to worry about. Any nation with the hubris to destroy GNSS birds deserves the nukes they suffer in return. Any nation who lets it happen, because the leader is numbnutted, deserves to suffer a breakdown for not being more mature in managing its geopolitical situation. Fifth Risk indeed.

tjohns 8y ago
Is eLORAN still actually happening in the US? Since we shut down our LORAN transmitters a few years ago, I assumed the plans for eLORAN went out the window with it.
- FlyMoreRockets 8y ago
  AFIK, everything is going to GPS and ADS-B.

SomeHacker44 8y ago

I would buy one in a heartbeat if true. I moved and neither of my watches (one Citizen and one Seiko) can get the Colorado signal anymore from the Northeast USA. But as other posters point out, I cannot imagine the FCC would allow those devices. But, OTOH, the propagation characteristics of any small device/antenna running at 60kHz would be abysmally bad and perhaps unworthy of notice. I would still not bet my several FCC licenses on it though.

anishathalye 8y ago

I made one of these GPS -> WWVB simulators a couple years ago. There's a short write-up here, in case anyone is interested in reading about it: https://www.anishathalye.com/2016/12/26/micro-wwvb/ https://www.anishathalye.com/2016/12/26/micro-wwvb/ There are also some neat iPhone apps that use the audio circuitry to produce a low-power signal that can be picked up by radio-controlled clocks that are close by: https://itunes.apple.com/us/app/clock-wave/id1073576068?mt=8 https://itunes.apple.com/us/app/clock-wave/id1073576068?mt=8 A couple people mentioned the FCC and licensing issues in the comments below. As far as I know, as long as you're transmitting at a very low power (40 µV/m as measured at 300m), it's okay. This should be fine for personal use, but won't work on a municipal level.

xiii1408 8y ago
Dude! That's freaking awesome. I've been wanting to set up a GPS-based NTP server for a while, but haven't gotten around to it yet. I'll have to read through and take a look at the transmitting equipment you used; adding WWVB to it would be awesomesauce.
escherplex 8y ago
Not bad! While reading the article the thought occurred that if WWV were eliminated then this would be a good opportunity for a smart phone app to pipe a GPS derived time standard emulating WWV format into a < 100mw (Part 15) 5, 10, or 15 MHz attached transmitter. And the idea was already objectified.