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Does anyone know how to ,or get info on, changing loran #s to Lat/Lon for GPS. Tup: Have 2 or 3 pages of old school halibut,ling cod, and sea bass spots but dont know where there at. :x :x
 

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There are commercially available programs that will do the conversion. Some charts had both Loran and GPS numbers on the borders.
 

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Do you have a newer Garmin GPS? If so, you are in luck.

This is from the Garmin website:

Q. Can I use Loran TD coordinates on my Garmin GPS?

A. Garmin has added the Loran TD format to most new GPS units. This will allow consumers who have used Loran in the past to enter their old Loran TD numbers into their new Garmin GPS receivers. The GPS does not receive a Loran signal. It will simply convert the Loran TD that you enter and convert it to Lat/Lon for display or navigation. You will need to know the Loran chain number and the two secondary towers used to record the position you wish to convert to Lat/Lon or navigate to. If you would like more information on Loran TDs and your Garmin GPS unit, please see our Loran TD Position Handbook
Once you have set up your GPS for Loran TDs, you will be able to enter your Loran TD positions. You can then switch the GPS back to Lat/Lon, and the coordinates will be converted. Since the GPS unit makes the conversion based on a static model, there may be error introduced. You can also get error if an incorrect primary/secondary station is used or the order of if the two secondary stations is incorrect. Because of this error, we recommended you mark these waypoints upon arrival, this time using the GPS signals received for the most accurate position.
 

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I may be a few years out of date but we converted to sat nav from loran in the 90's And it's the same if you use a paper chart and a compass And dividers ,
 

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I think you are asking about a fundamental understanding of charts , Because Lattitude for near seattle is near 49 degrees longitudeis something like 125 .38.40 Then there are 60 minutes with division of seconds between minutes so if you read 125 degrees 38 minutes 40 seconds , So look at the chart and figure the proportion of minutes and seconds between each degree and take the dividers and make the marks in the ocean , Use the loran or what ever nav device and go the Lat Long Is lat long ,
If you are asking how to use a computer so you can put the way point in then read the directions on the navigation booklet , or to get started type on the net , Navigation charts , Or nautical charts ,
Or are you trying to convert from one program to another ? Because as far as i know ever since loran till now Lat long is the same lat long as ever , And always will be ,
If you have a fundamental of charts then you could use lat long , a chart , and Loran and go any where ,
 

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Seed position? I love ya, but I'm not giving up the position of this years cash crop!!! :eek: Its been ages since I used it...punch in N47 54 W124 39 and see if it works? And Cod...most charts are in 10ths....that was my number one "mindscrew" to crewman....be sure to be "in synch" with seconds or tenths...multiply or divide by 6 as appropriate
 

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Cod and I just had some PM action, and I thought the reply might help a few others in understandig "how it works"... Navigation seems duanting at times but really it is bonehead math..LOL...I can do it so what does THAT tell you? And my apologies for not being clearer in earlier posts...my bad. If anyone has any ????s I will be happy to answer or tell you a VERY GOOD lie!!!
Afternoon, Cod!
In all you are saying you are for the most part correct, so I'll try and break it down without typing my fingers raw!! :lol: First and FOREMOST, the COAST GUARD invented, and still mans ALL LORAN stations, plus maintain all of the "D" in DGPS radio stations(more on that in a second). As I just left active CG duty...the Navy thing sticks in my craw! Now as to the chart thing you are correct as far as "flat" and Mercator projections. However, if you come across a flat projection chart it will probably be framed in an antique store! What DOES change is the Geodetic Survey Data used to MAKE the modern chart. WGS 27 and NAD83 are the 2 most common now, but there are several older systems that were used, and you may stumble across a chart using those older formats. Between the 2 in use, honestly the difference is SO SMALL as to not even be concerned about. I am a NAV GOD...and I could not pilot a small boat to those tolerances.
Now, you asked about the seconds, and AGAIN you are absolutely correct. The position I gave Lip was the requested "seed position" for the PROGRAM I sent him...It just has to be a very general position to let the program know where it is. It had nothing to do with any form of navigation. Degrees and Minutes suffice, kinda like "initializing" a GPS the first time it is turned on...it just needs a rough idea of where to start looking. Clear as mud?
Now as to SAT NAV...a fix, like any other fix requires 3 lines of position, be it visual, radar, or sattelite! The D in DGPS is an auxillary LAND based radio signal that sends the GPS receiver what is known as a PRC (psuedo-range correction). That signal transmits the sattelites real time position...sometimes an orbit will slightly speed up or slow down. This is why GPS has 100 yd accuracy, and DGPS is 10 yds or less. In time of war or when deemed necessary, the "D" signal will be scrambled so the bad guys can't be as precise as we are. I set Aids to Navigation for years (Yes, my heart was truly black!) and I can honestly tell you that using the Coast Guard positioning system I could set a bouy within the distance of someone sitting across your desk!!! That said, all Nav aids are not equal. They are assigned an "Accuracy Class" ranging from A (less than 10 yds) to E (get it in the water). The latest and greatest however is WAAS, this system is run by the FAA. It stands for Wide Area Augmentation System. This system was developed to basically allow commercial jets to land on autopilot!! :eek: While the CG uses DGPS for Aid positioning, all CG small boat Nav uses WAAS currently.
Now to answer your plotting ????'s..nothing has changed. True Virgins Make Dull Companions At Weddings, Can Dead Men Vote Twice At Elections will probably never change. My only point was to make sure that if the chart is in Degrees, Minutes, Seconds or Degrees, Minutes, TENTHS...you plot approriately or do a simple conversion if you need to.
Since my fingers are bloody now, I'm gonna copy this to the board in case it helps someone else! And if you have any other questions Cod, I will be more than happy to kick them around! Might cost you a beer tho wink:
Take Care,
Frank
 
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