eLORAN as source of correct time - Page 1
Forum section: electronics / rf-microwave

author: Peabody
author_rank: Super Contributor
timestamp: May 26, 2024, 02:25:25 pm
content: Has anyone seen a project to obtain GMT from an eLORAN data transmission - as another alternative to NTP, GPS or WWVB?

author: wilhe_jo
author_rank: Regular Contributor
timestamp: May 26, 2024, 03:55:48 pm
content: Wasn't LORAN shut down?73

author: TimFox
author_rank: Super Contributor
timestamp: May 26, 2024, 04:10:18 pm
content: “eLoran” is the replacement for the obsolete “LoranC”.I don’t know it’s current status.

author: ataradov
author_rank: Super Contributor
timestamp: May 26, 2024, 05:25:40 pm
content: No only it is not shut down, it got a lot of attention recently due to all the Russian messing with the GPS in the Baltics.But I don't think the cheap/civilian hardware is there to be a viable option. Hopefully it gets developed more.

author: Wallace Gasiewicz
author_rank: Super Contributor
timestamp: May 26, 2024, 10:18:26 pm
content: There was a test recently involving eLoran. They talked about it on the Time Nuts Mail group.I do not know what the current status is but there are plans to make it operational.I THINK the freq is 100 KHz

author: CaptDon
author_rank: Super Contributor
timestamp: May 27, 2024, 01:29:00 am
content: As a Merchant Mariner and professional working member of International Ship Masters it was very painful to me when the U.S.C.G. decided to turn off Loran-C!!! We had a 5 minute loss of GPS recently as a very severe storm passed by our position. The United States government spent 10's of millions to upgrade the older tube type Loran facilities to solid state with a much cleaner waveshape, then they shut it all down including demolishing the towers and the sites getting vandalized!!! Now they speak of E-Loran or enhanced loran with timecode data and other information included in the signal. Very wasteful to have scrapped the towers, transmitters and time standards!!! Your U.S. tax dollars at waste once again. And all the Loran-C stuff laying in the landfills!! Sad the new proposed system couldn't be compatible to the old receivers!! I have been arounf long enough to remember the old Loran A equipment with the oscilloscope tube display where you had a crap load of knobs to get the groups and delays stable on the scope tube!!! Took about 3 minutes to calculate and fix your position and you had to have the Loran overlay charts as none of the Loran A units I ever used gave a direct Lat/Lon readout!!! It's been years since I've seen a Loran overlay chart, and now NOAA has even stopped charts and chart booklets. I think the new version of electronic charts sucks!!! All built on vectors and funny looking symbols and polygons and about 6 overlay files!! Yuk!!!

author: Njk
author_rank: Frequent Contributor
timestamp: May 27, 2024, 05:08:32 pm
content: https://www.transportation.gov/administrations/assistant-secretary-research-and-technology/complementary-pnt-and-gps-backup

author: TimFox
author_rank: Super Contributor
timestamp: May 28, 2024, 03:53:36 pm
content: Recent news stories about the Russia-Ukraine war indicate that Russian electronic countermeasures (RF jamming) have become effective against GPS for smart munitions and Starlink satellite communications links.

author: CaptDon
author_rank: Super Contributor
timestamp: May 28, 2024, 04:44:25 pm
content: That link is a 457 page coverage of the topic. Very in-depth indeed!! Sadly eLoran and most of the other offerings are 2D unlike the 3D of GPS we have all come to enjoy. 3D could be very useful to hikers and mountainous S.A.R. operations. Aircraft have barometric altimeters as well as radar altimeters and for boats 'altitude' means very little. I do miss Loran C. It sure tore up radio communications if you were near a transmitter site!!!

author: Peabody
author_rank: Super Contributor
timestamp: May 29, 2024, 01:32:48 am
content: Well I was more interested in the time info provided by eLORAN. For data logging purposes, for example, if you don't have internet available in the wild, you're currently left with GPS or something like WWVB. But I assume eLORAN would have multiple broadcast transmitters, and would be another option.The last GPS module I bought works like a charm, and cost about $14. I was just wondering if something similar is being worked on for eLORAN.

author: ejeffrey
author_rank: Super Contributor
timestamp: May 30, 2024, 02:09:15 am
content: I don't think eLoran exists outside of demos? There is still interest in it from time to time for jamming resistance but I don't think it's actually been built.

author: ataradov
author_rank: Super Contributor
timestamp: May 30, 2024, 02:20:15 am
content: There is definitely no full network. The recent tests brought up some transmitters, but it is hard to tell how many and for how long. There is definitely nothing that could be considered commercially useful at this time.I don't know if it even makes sense to bring it up as is. It may be better to do something new with up to date technology.

author: coppercone2
author_rank: Super Contributor
timestamp: May 30, 2024, 02:30:16 am
content: i think there is a serious need because russian jammer technology (or is it chinese import?) seems to have efficiently countered many of the economical weapons in the NATO arsenal to a high degree of effect, based on news reports. Plus news of space objects. There should be a backup. The cost of the system vs the cost of the consequences makes me think the modernized LORAN system is extremely cost efficient insurance for navigation things remaining mostly normal regardless of the situation. Less fear means favorable negotiations with less leverage.