GPS DATA ON HARD MAPS / rulers for fine tuning?

Discussion in 'GPS Use, Tracks & Maps Discussion' started by PICO-PICO, Mar 6, 2007.


    PICO-PICO Ol'Timer

    I said before that I like the DELUXE ATLAS OF THAILAND published by
    The beauty in addition to really small details and topographic views is that it also contains GPS data based on WGS-84 system.
    < Not sure if that is the same system used by Garmin.>
    My question = if I look at the GPS grid on the map Mae Sariang is close to the crossing lines of 18.11.11,2 and 98.13.20,9.
    Is there a some kind of a ruler which gives readings between the grid lines? I guess no scale adjustment is necessary for GPS, right?
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    PICO-PICO Ol'Timer

    The Art of Asking Questions :)

    what I mean is=

    Can I use whatever type of ruler in oder to fix on the hard map a specific GPS point X which I then transfer onto my Garmin GPS??
    Would facilitate route planning.

    Hope I got it right this time.
  4. Auke

    Auke Ol'Timer

    Sorry, don't have my Thinknet map here with me but in principle you can measure with a ruler but it will be easier to use Decimal degrees (D.D) by measuring between 2 full degree lines.

    Another option is to buy the Thinknet CD (the same map as the paper version but in electronic format for use on the computer - I think I paid 299 Baht but that is quite some time ago) and then you can get the coordinates directly from the computer.

  5. tropicaljohno

    tropicaljohno Ol'Timer

    Auke already tried that option, unfortunately Thinknet CD no work on Apple Mac, I emailed company and they said have no intentions at present to put cd on for Mac

    PICO-PICO Ol'Timer

    I´m getting used to be called snobbish because of my love for MAC only, no divorce in sight, however.

    But I could well use the thinknet Cd in an internet cafe, as I wont be plotting new trips every day, right ?
  7. tropicaljohno

    tropicaljohno Ol'Timer

    Pico bribe me with a few sticky buns from your local bakery and I will give you a copy of Map Magic, both Thailand, and Bangkok.

    Was in Mr T bike shop in Bangkok yesterday, they have a really nice BMW 1100R with side car for sale, certainly looks the dogs boll**ks

    Big C here in Lam Luk Ka have lap top pc's for sale 16,990 baht.... with Windows on, (about time you came over from the dark (Mac) side, and joined the rest of us... viruses an' all)
  8. thebamboorat

    thebamboorat Active Member

    Pico - Pico

    One thing to aware of using GPS and standard topo maps is the dreaded projection problem. You have to know what projection the map-makers were using to create their maps. Here in Lao topo maps use Gaus – Kruger (Pulkovo 40) which is equivalent to Indian-Thai 48 or is that Indian-Thai 67 (or 68?).

    If you're recording waypoints and tracks in UTM WGS84 then they won't necessarily plot in the right place on the topo's (different projections). If however you've registered your topo's in WGS84 in a mapping program then no problems.

    If you are using the Thinknet Thai Atlas you are talking about and it is in WGS84 projection and you are recording data in WGS84 then your life should be easy and you can plot points straight on to and off it.

    Not quite sure what you mean about “scale” ???? A hard copy map should, if done properly, have the scale shown somewhere. You can buy triangular section, scale rulers which have six different scales on them. I think they’re available in Thailand. If you know the scale of the hardcopy map then you can easily measure points off using the appropriate scale on the ruler to load into your GPS.

    All GPS units will allow you to set up what datum you record data in. A Garmin will have a whole list of projections you can select under SETUP - UNITS. Set up your GPS in the same datum as the topo and away you go -if you can find out what projection the bloody topo is printed in that is, because the bastards generally don’t print this on the maps.

    After having dealt with the projection problem on and off for 4 years as part of my work I can tell you it can be a nightmare trying to sort it out if you are not a surveyor (I’m not!). The Vietnamese for example use a lovely WGS84 N00 projection for their topo’s which is WGS84 but with a couple of hundred metres shift thrown in (for security purposes or some such crap) Just to make it even more interesting the amount of shift can vary between Provinces dependant on alignment of the planets or the feng shui of the survey benchmark points or how much of a bastard the surveyor felt like being on that particular day.

    Anyway after having confused myself with explanation above my suggestion is to take the easy way out and do as Auke suggests and buy the CD – no issues with scale and just use your cursor to locate the point and read off the co-ordinates on the screen.
  9. Auke

    Auke Ol'Timer

    Yes, the Thinknet Thailand map is in WGS84 and if your Garmin GPS is set to WGS84 then it should in principle be quite straight forward taking a point from the map and calculating the position.

    You can set your GPS to WGS84 so then the coordinates at the GPS should be the same as at the map.

    And sorry, there is no ruler which can convert in an easy way distances on a map to a coordinate system so you will have to do a few calculations as this will depend on the projection, datum as well as the scale of the map.

    Mae Sariang (on the Mae Hongson map at page 83/84 of the 2005/2006 Thinknet map) is just north of the Latitude line of 18 9 7.3 (Degrees Minutes and Decimal Seconds or DDMMSS.S) and about halfway between the Longitude lines of 97 50 19 and 98 1 52.1

    If you measure the distance between the Latitude and Longitude lines you find that in the North/South direction the distance is about 44 mm and in the east/west direction about 43 mm. Concerting the millimeters into a coordinate you will get that every millimeter is about 16 seconds (roughly but good enough for calculation purposes). If you now measure the distance of Mae Sariang from the Lat/Lon lines you will find about 2mm in the northerly direction and 21 mm in the easterly direction. Converting the millimeters into Minutes and Seconds you find you will have to add about 32 seconds to the Lat line just below Mae Sariang and about 336 Seconds or 5 Minutes and 36 Seconds to the Lon line west of Mae Sariang. So Mae sariang should be about 19 9 39 (DDMMSS) N and 97 55 55 (DDMMSS) E.

  10. mikerust

    mikerust Ol'Timer


    Next time you come to BKK. Drop in at Noriega's Silom Soi 4 for a beer.

    NSR Mike

    PICO-PICO Ol'Timer

    Thank you very much indeed that you took so much effort to explain, Auke and BambooRat ! It´s interesting that both very comprehensive answers came from people living in Laos.

    Wish so much to ride Laos !!

  12. BignTall

    BignTall Ol'Timer

    Auke & Bamboorat - Fantastic answers you guys!! Good stuff.

    Mikerust - Noriegas bar. Not been there in awhile. Wondering if I can remember how to get to it when I'm over ther in a couple of weeks. Small world I met the bar owners brother here in LA.
  13. jimmyyeehaa

    jimmyyeehaa Active Member

    thanks for these replies im finding this learning curve a steep one

    i have spent such a lot of time scanning and importing maps of Thailand into fugawi or kashmir calibrating the map by going onto google earth and plotting the position of known towns then inporting my routes from GPS into the software only to find my route starts off fine around Chiang mai but by the time i get accross country i appear to be doing... well ...a hell of a lot more off road than i remember .....

    you have answered a lot of my questions [:)] i think

    basically i want to see a map of Thailand on my screen, create waypoints of places i already know or road junctions in a layer add little reminders and prompts
    and then upload the waypoints to GPS before heading out into the trails

    one day soon someone will come up with a programme that will convert a small simple raster map into a vector map we can upload to GPS without having to spend a huge amount of money buying a digital map of a whole country

    i think i will buy this map magic CD and mess around with it
    it sounds like it will be easier to get the lat long and plot positions and its not expensive

    any one want to share there work flow ?
    anyone got any views about which software they find easiest to use
    fugawi global navigator?
    Kashmir ?
    Garmin Map source ?


    PICO-PICO Ol'Timer

    Jim, I first thought the name "Isle of Mull" is from a Harry Potter book.
    No, it´s not =

    This is the particular fun of GT-Rider , so many different individuals.
    Good web site on Thailand you have!
  15. tropicaljohno

    tropicaljohno Ol'Timer

    Hi NSR Mike

    Will keep you informed, currently at the in-laws 1.5 hours east of Nong Khai, yesterday ordered a bike trailer which will take 1 week to build, so will sit it out up here in "Never Never Land" till trailer finished. At least have okayed it with Papa to watch ALL of MotoGP Saturday.

    Will be back up this way Songkran with bike(s) so if not make it this time, can meet up on return trip back up from Phuket
  16. mikerust

    mikerust Ol'Timer

    Yes the brother is coming here for a visit. That scares the dorky brother who lives here as he has to repay the favour and act as host.

    Soi 4 near Saladeang skytrain. We run Mondays and Wednesdays those those are not good for a visit before about 11pm!!
  17. daewoo

    daewoo Ol'Timer

    G'Day GPSers...

    Look, before I start, let me explain that my use of a GPS was nothing more than a quick lesson from my dad, then importing some maps for use on a single trip through Cambodia, so don't take anything I say as anything other than the experience of a complete novice...

    My dad used OziExplorer, so that is what I used... he didn't really show me how to use it, I taught myself over a couple of days to do the things I needed...

    I scanned the maps to PDF files using the photocopier/scanner at work... using OziExplorer and following the steps carefully you can import the map to OziExplorer... When you import the map it asks you what Datum you are using...

    Any good map will tell you which Datum they have used, usually in the box where the scale is represented, or with the publiching info... My Gecko Cambodia map is Indian Datum 1954... Neither my PN map nor my Lonely Planet Road Atlas stated what Datum they used, so I guessed at WGS84 since that is pretty much a default...

    The software then allowed you to put 4 or more waypoints over the imported map, for which you knew the co-ordinates... (use the intersection of gridlines)... you can do this with google earth as well... These are the reference points by which the software then extrapolates the co-ordinates for the rest of the map.

    After that, you can just click anywhere on the map and create a waypoint... It will know to use the Datum that the map was created using... I think that you can convert from one Datum to another inside the software...

    It is very hard when you don't know the Datum, I used WGS84 with the maps that I had which didn't list the datum, then checked the co-ordinates against Google Earth...

    For a really good guide for the rest of us... check out

    For more detail, go to

    You can buy (and try I think) OziExplorer from For the dishonest people, a google search will bring up a few sites where you can get cracks for the software... upon to you...

    When trying to work out co-ordinates with a ruler, be aware that the length between lines of latitide can change between the top and bottom of a page.

    I still have a table with the GPS Co-ordinates and still have the scanned maps for my planned trip from Burirum (Th) to Siem Reap (Cb) to Phnom Penh, to Sihanoukville to Trat (Th) if anyone wants them.

  18. tropicaljohno

    tropicaljohno Ol'Timer

    Daewoo, I had a demo of Oziexplorer GPS software when I was up in Chiang Mai, very impressed with it, just now saving up the $AUD80 to purchase a copy from the Land Downunder (wonder if they give free jars of Vegimite with each purchase)
  19. daewoo

    daewoo Ol'Timer

    I bloody hope not... that stuff is a bio-hazzard... [:D]

    My dad was a very keen 4WDer... he used the software plugged into his laptop to go everywhere in Australia, and track everywhere he went...

    I know he tried 2 other programs, Fugawei and something else before getting the OziExplorer and decided it was the best...

    I am pretty sure it was only a small program less than a CD... I think I gave my dad's copy back to my mum, but if it is there I would be willing to share it, either by BitTorrent or mailing a CD... although saving you $US85 would mean that you owed me a fair few beers...

    IF I CAN FIND IT... otherwise look for the cracked versions...


    PICO-PICO Ol'Timer


    CAN I BID MORE ......... BEER ?? Might be worth a very thorough search
    Would even buy a PC :))

  21. daewoo

    daewoo Ol'Timer


    I don't mind sharing with a few people, no need for a bidding war... but I don't want it to get out of hand...

    You would need a PC, or access to one though (to use it, not before I would send it)...

    You also need to look at getting yourself the serial cable so that you can connect your GPS to the computer and upload/download all the waypoints... I got mine through GPSoz... or If you need me to buy it on your behalf and ship it I could do that...

    The set up in my dad's 4WD was pretty neat... with the GPS plugged into his laptop it would plot the route onto the map being displayed on the screen, and he could save the route to review or re-use later...

    I think that you can do the same thing using a palmtop, or palm pilot or PDA or whatever they are called... I am a bit of a technophobe...

  22. tropicaljohno

    tropicaljohno Ol'Timer

    Daewoo funny I was just thinking on the same lines of if its possible to link GPS to pc, I do a fair bit of sailing over hear, and all the yachts I sail on have a gps no bigger than an egg plugged straight into lap top and you can watch where you are on pc screen, and of courses yachties have the ocean charts already downloaded....

    My Garmin comes with pc cable and have already been shown how to download waypoints and tracks onto pc, which is great, to be able to back up everything.
  23. tropicaljohno

    tropicaljohno Ol'Timer

    Daewoo funny I was just thinking on the same lines of if its possible to link GPS to pc, I do a fair bit of sailing over hear, and all the yachts I sail on have a gps no bigger than an egg plugged straight into lap top and you can watch where you are on pc screen, and of courses yachties have the ocean charts already downloaded....

    My Garmin comes with pc cable and have already been shown how to download waypoints and tracks onto pc, which is great, to be able to back up everything.

    PICO-PICO Ol'Timer

    Darryl, sent a PN. Will liase with TJ as we are next door neighbors
    Thanks for offer
  25. jimmyyeehaa

    jimmyyeehaa Active Member

    thanks everyone for great replies to my problems, what great help and what a great community we are.

    i have downloaded oziexplorer so will have a look at that.
    my wife is in BKK this week and she bought me the maps - out of stock in bookazine but she went to the university book store and got the map there... and a discount ! price 250 Baht cool.

    Ayyee Pico Mulls a great place in the summer, pretty dead and cold and grey in the winter and thats why we like to spend our winters in Thailand, i have never met Harry Potter, they did some of the filming North of here at a place called Glen Finnan where they have that big curved railway viaduct, remember that bit ? well i lived in a caravan for a month under that viaduck working on the estate and i what i remember is that have never ever come accross so many different beasties that wanted to eat, suck, bite, chew and sting me.
    Glen Finnan was and should always be remembered as the place were the Scottish clans gathered before they embarked upon their adventure to boot the English out of Scotland.


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