All,

I see alot of speculation in regard to LORAN-C and it's future here.

I am currently stationed at the USCG Navigation Center in Alexandria. This issue affects my command Directly and my actual job.

I highly reccomend to all concerned to refer to the NAVCEN website for official info on this matter, as NAVCEN will be the Key component in the future of LORAN, rather than resorting to scuttle butt. I have the LCCS watchstanders sitting right behind me, and LORAN Management down the hall, so you really can't get closer than that.

I won't divulge any info more than what is posted on our website nor offer my opinion. But i will say this, GPS (accurate within 3-10 meters) is our primary for PNT, DGPS (accurate within 3 meters) is a strong second and LORAN is a tirciary system in use since 1948 by creation of Dr. Alfred L. Loomis as LRN (Loomis Radio Navigation) and is accurate within .25 Nautical miles. You can draw your own conclusions from that.

quote:

Originally posted by robandrews:
All,

I see alot of speculation in regard to LORAN-C and it's future here.

I am currently stationed at the USCG Navigation Center in Alexandria. This issue affects my command Directly and my actual job.

I highly reccomend to all concerned to refer to the NAVCEN website for official info on this matter, as NAVCEN will be the Key component in the future of LORAN, rather than resorting to scuttle butt. I have the LCCS watchstanders sitting right behind me, and LORAN Management down the hall, so you really can't get closer than that.

I won't divulge any info more than what is posted on our website nor offer my opinion. But i will say this, GPS (accurate within 3-10 meters) is our primary for PNT, DGPS (accurate within 3 meters) is a strong second and LORAN is a tirciary system in use since 1948 by creation of Dr. Alfred L. Loomis as LRN (Loomis Radio Navigation) and is accurate within .25 Nautical miles. You can draw your own conclusions from that.

Where did you get the 1948 date for LORAN?

While researching another project at the National Archives, I came across the original documents discussing the work that was going on at MIT with LORAN A. This was circa 1940. I found the original paperwork outlining how these new LORAN stations would be set up in Greenland and run by the CG. It showed what the crew makeup would be and what ratings would run these LORAN units.

I went back earlier this year to relocate the documents but couldn't find them. I know what boxes they were in. It will take a day to thoroughly go thru the boxes again to relocate the documents. Interesting history.

Jamming GPS will make that 3-10 meters seem like a pipe dream.

As a navigation system, I agree, Loran-C isn't as good as GPS. DGPS, maybe accurate to within 3 meters, but how does that compare when your jamming GPS signals? I doubt your touted less than 3 meters will be available, especially if your information is realtime from a receiver in the jammed area.

As I recall, NAVCEN's 39 hours to identify the source of the jamming by the Navy caused the CO at the time to apologize for that dismal performance.

Loran, as created by Dr Loomis, demostrated repeatability to a very high degree by navigating a dirigible right back to their tiedowns. That story was told by Dr Loomis.

I agree the geodetic positioning is a lousy 0.25 nautical miles, but, with the ability of UTC synchronization of the units, all in view receivers, and getting rid of System Area Monitor control, it should improve the geodetic position greatly. Grid warp, caused by SAM control, was reported by R&D Groton in the 1980s, if my memory is correct.

Since that 0.25 nM was thrown out, when is it going to be updated with the improvements made so far?

And for the record, Loran-A geodetic positioning wasn't 0.25 nM, it was 1 to 4 NM, as reported to the 1975 Offshore Technology Conference by James F Culberson USCG.

John,

1948 was the publishing date of the MIT Radiation Lab Series. Volume 4 is Loran.

October 1940 is when Dr Loomis, chair of the Microwave Committee, proposed the system that became Loran.

Funny thing, my copy of Volume 4,surveyed from the U.S. Naval PostGraduate School once belonged to J.F. Culbertson, LT, USCG (his name is stamped in no less than five places)

I recall Culbertson as the Admiral who signed the 1981 Signal Specifications for Transmitted Loran-C Signals, a Commandant Instruction.

This message has been edited. Last edited by: JoeJester,

quote:

Originally posted by TVCJohn:

quote:

Originally posted by robandrews:
All,

I see alot of speculation in regard to LORAN-C and it's future here.

I am currently stationed at the USCG Navigation Center in Alexandria. This issue affects my command Directly and my actual job.

I highly reccomend to all concerned to refer to the NAVCEN website for official info on this matter, as NAVCEN will be the Key component in the future of LORAN, rather than resorting to scuttle butt. I have the LCCS watchstanders sitting right behind me, and LORAN Management down the hall, so you really can't get closer than that.

I won't divulge any info more than what is posted on our website nor offer my opinion. But i will say this, GPS (accurate within 3-10 meters) is our primary for PNT, DGPS (accurate within 3 meters) is a strong second and LORAN is a tirciary system in use since 1948 by creation of Dr. Alfred L. Loomis as LRN (Loomis Radio Navigation) and is accurate within .25 Nautical miles. You can draw your own conclusions from that.

Where did you get the 1948 date for LORAN?

While researching another project at the National Archives, I came across the original documents discussing the work that was going on at MIT with LORAN A. This was circa 1940. I found the original paperwork outlining how these new LORAN stations would be set up in Greenland and run by the CG. It showed what the crew makeup would be and what ratings would run these LORAN units.

I went back earlier this year to relocate the documents but couldn't find them. I know what boxes they were in. It will take a day to thoroughly go thru the boxes again to relocate the documents. Interesting history.

Master Chief,

Respectfully request to inform you that 1948 is the year indicated by the NAVCEN NIS (Navigation Information Service) watch stander PQS. The date is indicated several time through our required reading for qualification.

V/R

OS2 A

LORAN C 1948 ???

quote:

Originally posted by JoeJester:
Jamming GPS will make that 3-10 meters seem like a pipe dream.

As a navigation system, I agree, Loran-C isn't as good as GPS. DGPS, maybe accurate to within 3 meters, but how does that compare when your jamming GPS signals? I doubt your touted less than 3 meters will be available, especially if your information is realtime from a receiver in the jammed area.

As I recall, NAVCEN's 39 hours to identify the source of the jamming by the Navy caused the CO at the time to apologize for that dismal performance.

Loran, as created by Dr Loomis, demostrated repeatability to a very high degree by navigating a dirigible right back to their tiedowns. That story was told by Dr Loomis.

I agree the geodetic positioning is a lousy 0.25 nautical miles, but, with the ability of UTC synchronization of the units, all in view receivers, and getting rid of System Area Monitor control, it should improve the geodetic position greatly. Grid warp, caused by SAM control, was reported by R&D Groton in the 1980s, if my memory is correct.

Since that 0.25 nM was thrown out, when is it going to be updated with the improvements made so far?

And for the record, Loran-A geodetic positioning wasn't 0.25 nM, it was 1 to 4 NM, as reported to the 1975 Offshore Technology Conference by James F Culberson USCG.

John,

1948 was the publishing date of the MIT Radiation Lab Series. Volume 4 is Loran.

October 1940 is when Dr Loomis, chair of the Microwave Committee, proposed the system that became Loran.

Funny thing, my copy of Volume 4,surveyed from the U.S. Naval PostGraduate School once belonged to J.F. Culbertson, LT, USCG (his name is stamped in no less than five places)

I recall Culbertson as the Admiral who signed the 1981 Signal Specifications for Transmitted Loran-C Signals, a Commandant Instruction.

Hi Chief, always a pleasure to speak with you. One of the primary functions for NIS watch standers is GPS Testing Even Coordination. I actually wrote the current SOP used here along with 58 other SOP's. Testing in affected areas would of course shoot any chance of 3 - 10 to the lower depths of hell. DGPS will also not perform at all in an affected testing area (i.e. if GPS don't work, neither will DGPS).

If you are referring to the event that took place in January 2007, I was the one who took the initial report. Without getting into to much detail, it became the catalyst by which we operate all detection and interagency coordination for multiple outage events. Needless to say...we're on it and have not had a repeat since.

As far as your LORAN question goes, your guess is as good as mine. but i would mention that anything to do with updating loran or shutting it off is going to come down to simple numbers.
The budget mandates to save us 190 million by cutting LORAN out. Shut down costs would be about 40 million less than that.

If we moved everything over to e-loran, with all the site maintenance and updates the cost in a heck of a lot more. It comes to what is feasible. But, I'm an E-5 not a congressman so I have no say in the matter

V/R

OS2

quote:

Originally posted by Mastersmate:
LORAN C 1948 ???

LRN (Loomis Radio Navigation) was an American civil development (Dr. Loomis) of the British GEE radio navigation system. Technically not operational until 1948. GEE was in use durring WWII. LORAN-A was in use by us durring WWII, but in use for military only.

This message has been edited. Last edited by: robandrews,

quote:

Technically not operational until 1948.

Rob,

You seriously need to get ahold of the RADLAB series.....

LRN was Loran Radio Navigation. Loran was coined by Capt L.M. Harding, USCG. It's just a coincidence Loran and Loomis share a common first letter.

What are your resources for your stuff....

1L3 rate went to continuous operation on Jan 15, 1944 ... with the last of the war time stations going to continuous operations Jun 14, 1945. Granted, they were a secret, military operation, but they certainly were operational.

They couldn't put those units in fast enough.

Loran-A was entirely different format than GEE. The only thing they had in common was they both were hyperbolic systems. GEE operated about 30 MHz and later about 80 MHz. Loran-A has operated in the 160 meter band (1.8-2.0 MHz). Loran-A operated with a 40 uS pulse, GEE - 6 uS. The frequency and pulse width of GEE made it much shorter range than Loran-A.

GEE's contribution to Loran was the dual-trace oscilloscope.

Both got their origins in the inverse hyperbolic mode of determining the location of the big guns of WWI, taking the distance (time) and direction from the listening post to the weapon.

I see the NAVCEN website still is providing false information ...

quote:

LORAN-C was originally developed to provide radionavigation service for U.S. coastal waters & was later expanded to include complete coverage of the continental U.S. as well as most of Alaska.

The first operational Loran-C chain was the MedSea. Three stations were declared operational in Aug 1959.

You can read some of the historical documents at http://www.loran-history.info

Has GPS been declared operational for civilian use yet? It has been a military system since NAVSTAR.

quote:

LRN was Loran Radio Navigation. Loran was coined by Capt L.M. Harding, USCG. It's just a coincidence Loran and Loomis share a common first letter.

Joe;
Knowing NO SPECIFICS on the history here, I am gonna have to waive the 'I don't think so' flag there. I REALLY DOUBT that LRN meant Long Range Aid to Navigation Radio Navigation as you say there. Doesn't pass the basic smell test. How sure are you of that?

Sunnamagum, It is in the first chapter, early history of LORAN. Interesting reading.

*Loran is a word coined by the then Lt. Comdr. L. M. Harding, USCG in early 1942 from the indicated letters of "LOng range RAdio Navigation."

http://www.uscg.mil/history/STATIONS/loran_index.asp

Which reinforces that flag I was waiving that LRN is NOT LOng range Radio Navigation Radio Navigation, and likely WAS Loomis Radio Navigation until the ACRONYM (not really a word) LORAN was coined.

Joe, I am old & forgetful, and a life long loranimal, but I always knew LORAN to be: Long Range Navigation. That's what I was taught, (by you, I believe) and is what I taught for my 10+ years of Loran.

And if you hear from Bill Dietz, please tell him I said hello!

TJ

Phil,

Dr Loomis proposed a Long Range Navigation system ... baselines of 500 miles or better. The L could be Long.

quote:

from Chapter 2, History of Loran
The Loomis navigation system proposal was accepted by the Microwave Committee and established as Project 3. A coordination subcommitteee whose first recorded minutes are dated Dec 20, 1940, wa formed to arrange for the procurement, installation, and field testing of one pair of transmitting stations and suitable navigation equipment outlined in the original proposal.

In June 1942, the first two stations were up and running ... operated by the MIT teams, LCDR Harding joined the project that month. It wasn't until Oct 1942 that the original procurement of equipment was issued buying 250 LRN-1 and LRN-1A shipboard receiver indicators. That was the first usage of LRN in the MIT Radiation Lab Volume 4 that I've seen in the history section. It is quite feesible for Harding to coin the phrase early on in his assignment ... and it's equally feesible that it was named for the Chair of the Microwave Committee, as the history section is unclear on the L. With the secrecy surrounding the subject, Loran would be my choice as it IS an acronym and not tied to Long or Loomis. Long or Loomis could lead the enemy to the purpose of the system.

TJ ... I taught Loran was Long Range Aid to Navigation. Long Range Navigation gives the illusion of an absolute, and the navigators should never rely on one form of navigation. Aye aye on the hello to Bill.

Slightly off subject but: Would any of you folks happen to have a picture of a received Loran A signal? I'm thinking of the early sets where we had to line up the signals on the pedastals, then read the numbers off a dial before plotting them. Sure can't seem to find anything on the web.....thanks and regards....Bill

IF you can find a 12th Edition of DUTTONS Navigation & Piloting, on pg 313 theres a good series of photos of the three steps to line up the signals and a photo of the AN?UPN-12 LORAN receiver we used.

Don't have a flat bed scanner to grab the photos, a sketch maybe.

This message has been edited. Last edited by: Mastersmate,

quote:

TJ ... I taught Loran was Long Range Aid to Navigation. Long Range Navigation gives the illusion of an absolute, and the navigators should never rely on one form of navigation. Aye aye on the hello to Bill.

Joe, I wish I still had my notes! But they turned to dust decades ago!!

Well, TJ, who knows ... I may have mentioned it the way you described.

The Loran-A signals were on pedestals and then you matched the leading edge of the envelope. Then you got to interpolate the dial readings.

However, here is a pic of the Loran-A indicators as illustrated in the MIT Radiation Lab Series 4

quote:

Originally posted by JoeJester:

quote:

Technically not operational until 1948.

Rob,

You seriously need to get ahold of the RADLAB series.....

LRN was Loran Radio Navigation. Loran was coined by Capt L.M. Harding, USCG. It's just a coincidence Loran and Loomis share a common first letter.

What are your resources for your stuff....

1L3 rate went to continuous operation on Jan 15, 1944 ... with the last of the war time stations going to continuous operations Jun 14, 1945. Granted, they were a secret, military operation, but they certainly were operational.

They couldn't put those units in fast enough.

Loran-A was entirely different format than GEE. The only thing they had in common was they both were hyperbolic systems. GEE operated about 30 MHz and later about 80 MHz. Loran-A has operated in the 160 meter band (1.8-2.0 MHz). Loran-A operated with a 40 uS pulse, GEE - 6 uS. The frequency and pulse width of GEE made it much shorter range than Loran-A.

GEE's contribution to Loran was the dual-trace oscilloscope.

Both got their origins in the inverse hyperbolic mode of determining the location of the big guns of WWI, taking the distance (time) and direction from the listening post to the weapon.

I see the NAVCEN website still is providing false information ...

quote:

LORAN-C was originally developed to provide radionavigation service for U.S. coastal waters & was later expanded to include complete coverage of the continental U.S. as well as most of Alaska.

The first operational Loran-C chain was the MedSea. Three stations were declared operational in Aug 1959.

You can read some of the historical documents at http://www.loran-history.info

Has GPS been declared operational for civilian use yet? It has been a military system since NAVSTAR.

Joe,

I've been going nuts trying to find the reference where I read that in 2006 for my watch qualification. But every book I've pulled from our library here confirms LRN as "Long Range Navigation" (i.e. 6th edition Radar & Electronic Navigation by G.J. Sonnenberg, circa 1988, among other books) So, as I see it you're right on that. As for operational dates I'm only finding "1940's" (LORAN-c Users Hand book).

I'm turning 30 on Monday, so maybe my memory is slipping on me already, but I'm positive I read the previous stated facts in references and publications here. From a watch standers prospective, the history of the systems operated here is not as important as maintaining availability. As long as we know the principles of operation and have the ability to troubleshoot, we're good to go. The experts, historians, scientists & scholars are definitely above the watch stander pay grades

Masters Mate and Joe Jester: thanks for the pictures....Regards....Bill

Rob,

I'm not doubting you've read it somewhere, it's just that your sources and my sources do not jive.

We can not proclaim a system operational only when the civilians decide to start using it ... if that were the case, no CG Cutter could be declared operational till they did their first SAR case ...

Dr Loomis was part of the NDRC ... National Defense Research Council so Loran was never a civilian design. It's sole purpose was military since the proposal that Oct 1940. Civilian usage came afterwards. The same applies to Loran-C and it's development in the 50s culminating in the deployment of the MedSea Chain going operational in 1959. There was one user back then, the U.S. Navy. NASA used Loran for timing and one unit had received a phone call cancelling their scheduled off air because of a pending Apollo launch.

The East Coast Chain was a testing chain till being declared operational in the 1960s. We like to think of the East Coast Chain as being first because of their role in the testing phase, but they were declared operational after the MEDSEA. In the 1960s, the AN/FPN-42 and the AN/FPN-44/45 transmitters were prevelent. The mid 60s is the time of the 44/45 transmitters (and 46 times) while the early 60s was the 41 timers and 42 transmitters. The timers that paired with the 39 transmitters was the AN/FPN-38.

A major improvement in timing and pulse control came in the early and mid 70s with the advent of the LRE (Loran Replacement Equipment suite).

The next jump was when the US declared a 200 mile limit and the East Coast Chain was split into two chains, NEUS and SEUS ... and we, the US, added the Gulf of Alaska chains. NEUS/SEUS received the SSX tranmitters, GOA and WC got the 44's, and Caribou, Nantucket, Carolina Beach, and Jupiter Florida retained their AN/FPN-42 transmitters. Caribou was a testing station up till the creation of the NEUS and CEC chains. This was done in the late 70s.

The final jump in coverage was filling in the mid-continent GAP with the inclusion of four new SSX stations, Boise City, Gillette, Las Cruces, and Havre in the early 90's. December 25th, 1990 is when the SOCUS chain, minus Las Cruces, was declared operational. That was the OPCON, CDR Perry Campbell's Christmas present to the users. In May, 1991, Las Cruces was declared operational. Boise City was placed into service (commissing ceremony) on Nov 8th 1990, although they were transmitting a Loran Signal since late August/early September of 1990.