US west coast eLoran test in progress (GRI 5990)

jks

I happened to stumble across very strong 100 kHz Loran-C on the KPH (California west coast) Kiwi last night. A GRI of 5990 is normally the Russia Caucasus chain, which is active according to the Germany-based recordings of DF6NM. But there was no way KPH was hearing that.

After some Googling and listening on multiple Kiwis concluded that this is an eLoran test using Loran-C stations:

• George, WA as primary (M-slot with 9th pulse)
• Havre, MT (overlapping M-slot in some cases which is strange)
• Fallon, NV (Z-slot)

It is apparently scheduled to continue until August or September. The only Kiwi that captured all three was in southern Alberta:

jks

The Loran-C extension in v1.619 has a new menu entry for the eLoran test. It says GRI 5991 because that allowed me to change far less code to deal with the existing 5900 Caucasus entry. But of course the actual GRI used for the timing calculations is 5990.

Here's a capture of the GRI 5990 Caucasus and GRI 8000 Western Chayka chains from the UA4CC Kiwi. So 5900 is also active in that part of the world:

Bruiser

Is possible to time synch off of eLORAN for clock, like the GPS receiver in KiwiSDR conditions the clock?

jks

Good question. A few problems I can think of:

• I don't know the format of the data contained in the eLoran transmissions. Is it published anywhere?
• So far, these tests only run for a short period of time (months) every few years.

Bruiser

This is what I have found, maybe it can help?

http://www.ursanav.com/wp-content/uploads/UrsaNav-ILA-40-eLoran-Signal-Specification-Tutorial.pdf

I am under the impression that eLORAN is the back up for when GPS is not available and will be a full time system in operation eventually alongside GPS.

https://rntfnd.org/wp-content/uploads/2018/04/Delivering-a-National-Timescale-Using-eLoran-Ver1-0.pdf

Here's another one I found.

jks

Nice capture of all three sites from the VE6JY Kiwi in Lamont, Alberta. Note that Havre, MT has reduced tx delay, moving from the old Z slot to the X slot. And Fallon, NV overlaps the 9th pulse (primary station id) of George, WA.

The MXYZ slot definitions are the old ones from when this was the 5990 nav chain (M: Williams Lake, X: Shoal Cove, Y: George, Z: Port Hardy). So they don't have any particular significance to the current test. Interesting that they are moving this around though..

jks

24 hours later, more tx delay changes. Fallon NV in the X slot, Havre MT in Y.