First off, welcome aboard Mike! I am looking to pick some up valuable info and tips for offshore fishing from you and the hordes of other anglers out there!
Now, I am by no means as computer savvy as some of the other members on this board. I was looking into a conversion program myself, during the summer, and was unable to find an "off the shelf program" that converts Loran TDs to Lat/Long. There are some that convert TDs to GPS but I will have to do some looking to find them.
As you may know, there are methods that can be used to convert them manually. They are described on the USCG website as well as the NOAA website.
There is an interesting article on the conversion problem I came across on the BOATS.com website:
Hopefully somebody will come up with a good answer for conversion. Some the newer chart publishers have done it for NJ coast,I fish with a friend that interfaced his loran with his gps,and I was able to copy some of "Our" sites.One site is www.charterboatcharts.com
Maybe this is a start.
JUst look at the TD lines on the chart and read the numbers in Lat & Long? Why do so many people have so much trouble doing this?
Every Loran has its own tuning differances so that whats right on in my boat may be 30 or 50 feet awy in your boat. There is no comfuser in the world that could possibily figure out the fudge factor. Just plot the course and when you get there with your loran you make a waypoint on your GPS machine.
CAPTWALT-- That's not the problem.Most all can read the LAT/LON from the charts. But if I give you some Loran TD numbers, can you tell me the GPS numbers.Here is an example: Loran 26897.8 43154.9 Tell me the GPS LAT/LON.
Mahi Mahi-- On the money! Can you tell me what to do on that site,it looks to me that it is DOS.Is there a microsoft version ? It would be great, a lot of guys where I'm at will tell me the loran numbers for some fishing spots,because they don't have GPS on the boat,and We do have a computer at the marina.
Glad to hear that it worked. If you go to the link and hit the posaid file which is highlighted, it will download to your computer as a compressed DOS file. It will appear as posaid. Click on the icon. It will decompress. There should be three files. Hit the posaid.exe file and the menu will appear. You'll have a choice of converting TD to Lat/Long or vise versa. I'm running Windows 98 and it seems to work perfectly. BTW-it will give your coord down to seconds (I didn't include them in the numbers on the previous post). Good luck. If you have difficulty, feel free to email me at: [email protected]
NANSEA: If I had a New Jersey Chart of the area I could just cross referance the TDs to LAT/LONG
The Garden State South Articial Reef is approximatly7 miles from the "LE" and is constructed mainly of Tire Units and Wrecks and Rubble. It is well suited for drifing for sea bass and fluke and bluefish. There are good sized Tautog on the various wrecks and rubble.
Garmin came out with a new GPS-The Garmin 182,it converts the Loran numbers automatically for you.It costs $699 at West Marine. They are coming out with a color version the end of this month (Garmin 182C)for $999.
You can't convert with any accuracy. My Furuno has Loran option, plugging in numbers from my Apelco loran was worthless.
Why would you want to anyway ? Here are several scenarios:
1)If you have reliable Loran numbers (verified with a particular machine) and you now own a GPS, let your Loran guide you to the spot and save the waypoint with your GPS. Fool proof. Use two boats if necessary (one has loran, one GPS, vice versa, etc).
2)Somebody gave you Loran numbers, they probably wouldn't have lined up with your Loran even if you had one (without some searching)see number 3. Plotting the loran numbers accurately on a nautical chart with Loran overlay and reading Lat/Lon from the grid is as close as anything you calculate. Or use two boat method above.
3) You have Loran numbers from a chart for a wreck but not Lat/Lon. Lat/Lon numbers for ALL wrecks found on Loran charts are available if you search the internet carefully. Keep in mind that these numbers are generally given in DEG.MIN.SEC, GPS generally use DEG.MIN format. Conversion is easy is you are OK at math.
Also, some LAT/LON available off the web are referenced to a differant Datum (reference point) as are nautical charts and GPS itself. Datum conversion is easy, but most be known for a particular area. Maptech software (and probably others)can convert for you.
If anyone has specific questions, shoot me an email, I'll try to help.
Paulh - LAT/LON are a world wide system and never change.There are only 2 points of reference: Lat is based at the equator which is 0 deg. and Lon is based at the poles which pass thru Greenwich.
Some of the newer charts have both TD and GPS numbers.
However if I am out fishing and someone tells me to go to a point (Loran), and I have a GPS I can't get there.
Also WAAS GPS give D.M.S.and the accuracy is within 3Meters.
If someone radios a GPS coordinate you can enter it into your GPS and track to it on the dime.
NanSea - Hate to tell you but Lat Lon is referenced to several different Datums (reference points). The earth isn't round, and the science of cartography (mapping) and the advent of GPS are pushing the need for better Datum's. Look closely at your nautical chart, you will see what datum was used. The differences are minor, if someone gives you lat/lon for large structure (cholera banks, 17, ) you'll never know the difference. GPS numbers have only become more transferable since SA was turned off, before that LORAN was much better (40-50 ft) vs. 50-100 yards. WAAS and DGPS are great, however, the governments own data base of wrecks (AWOIS) is referenced to the North American 1927 datum. Your GPS is not !! The conversion is different for various points on the globe. Check out Maptech S/W and others, they will convert the numbers for you. The offset is relatively small, but if you're into wreck fishing, and not merely trying to get on the wreck, but hit its sweet spot, you need all the help you can get. Good Luck.