Rtsd - 1:4,000

[GWR]

Located in the vicinity of its overseer, the Ministry of Defence on Thanon Kalayanamit. This is for those of you who have enough Thai to apply for residency. I believe it is possible to order 1:50,000 maps online or as downloads. However, many areas are unavailable due to security concerns. For example, Ranong's Bald Mountain (heavily featured in TV ads) is off limits as it was once a military airstrip back around World War II. (The irony is, I believe you can get a map of the area with the present Ranong Airport, which almost certainly still has military use.)

Let me know if you have any success by turning up on the doorstep to buy maps. I know expats who have successfully ordered maps by post from this establishment.
Royal Thai Survey Dept (http://www.rtsd.mi.th/)

[wokyai]

I got a couple of the 1:50,000 maps there about 2.5 years ago. I've forgotten how much they were (probably 70-80 baht apiece), but the process wasn't too difficult. Really, the hardest part was finding the place. I don't think the entrance was well marked from the street...seems like you have to duck in through an archway before getting to the door. Lonely Planet (how I heard about the place) says it's opposite the Interior Ministry on the western side of Thanon Ratchini in Ko Ratanakosin, very near Wat Ratchabophit, with entrance on Thanon Kanlayana Maitri. I'm pretty sure I looked at the building it's in from the street, didn't see a sign, then circled the block before deciding it must be the place.

Getting a map wasn't too hard, even with my rudimentary knowledge of Thai (at that time, about 8 months time in-country). I just told them I wanted a map, told them the province and district (jungwat and amphur), and they brought out a book that had the available maps and how they were divided. Naturally the location I was looking for was right at the point where 4 maps meet, and two of the maps were unavailable because they contained the Bhumibol Dam area. But the staff was helpful and friendly. Just make sure they know you want the 1:50,000 rather than the 1:250,000, writing it down if necessary.

[GWR]

Some further observations on RTSD.

The 1:250,000 series are available for most of the country, but some maps around Bangkok are now out of stock. Thes maps are collectable in as much as they are highly attractive. However, I note that many of them were last mapped back in the 1980s; although I did find some from 1999. At 70 Baht, incredible value; and great for decorative purposes.

I particularly like the 1:50,000 series, but vast areas of the south (and other border areas) are unavailable in this series. They are apparently militarily sensitive. 80 Baht per sheet.

The department is easily found, as per details found elsewhere in this forum section. Staff are friendly and helpful, but may need to be convinced that you do not intend to use their maps for any nefarious purposes. It should always be remembered that this is a department of the Ministry of Defence. It's best for the buyer to represent herself/himself as a map enthusiast.I notice, for example, that they don't really like posting maps; despite it being an advertised service. They seem genuinely concerned that their products will fall into the hands of terrorists.

Greater Bangkok maps are 80 Baht a sheet. There are also Thematic maps and Sat images on sale. Plus a huge American Defense Department World Wall Map; a real snip at about 250 Baht.

I would recommend a visit to RTSD. Something different only a step off the conventional tourist & backpacker trail. And something to be learned about the true reality of Thailand into the bargain.

[GWR]

Some example scans of RTSD's 1:250,000 & 1:50,000 Maps as featured in Khun Wisarut,Van Hirschorn & Hat-Yai Dysfunction's discussion of mystery rail lines in Thailand, from the 'SRT' Forum of 2Bkk.com. some of the original links have disappeared, but here are some I saved:-
http://pub8.bravenet.com/photocenter/album.php?usernum=633867102&album=24220

[GWR]

According to Siangtai Times (17/3/05) PM Taksin has given the go ahead to the creation of a new 1:4,000 map from satellite data. It appears that many government ministeries had been planning to create their own mapping for development & GIS purposes. After discussions with the PM on Monday, the various agencies decided to proceed with a single cover-all mapping project; according to Deputy Agriculture & Cooperatives Minister, Newin Chidchob. The project is expected to cost 5.6 Billion Baht, and should be completed within the next six months. This mapping should improve the government’s effectiveness in areas such as the issuing of land documents, natural disaster prediction and the management of the country’s 25 major river basins.

Note here that Land Ownership Documents are 1:1,000

Khun Newin’s dogged following of the PM seems to have lead to early dividends. Pity it didn’t lead to promotion as well! ;)

[GWR]

This Index map from Berkeley University Library should help you to locate the map order numbers for any 1:50,000 map you want to order from RTSD online, in person, on the phone or by post. Click on the map for greater detail:-

http://www.lib.berkeley.edu/EART/maps/thailand50k.jpg

Contact Details in earlier posts:-

http://www.rtsd.mi.th/

[GWR]

I believe this is the only triangulation point I've ever consciously seen in Thailand, although I'm quite familiar with the Chi Nodes of the Land Office. And this is actually a Ministry of the Interior - Department of Lands Trig Point at Wat Pawong, just a short distance towards Hat-Yai (on the left) from See-Yahk Prem on the 'Old Road'. These pictures were taken during a recent visit to the the 'graves' of family ancestors of 'Er Indoors. This trig point is just inside the temple gate at N 07 Deg, 07.538 Min, E 100 Deg, 34.478 Min (Elevation 9 M). In true 'Kah Ratchagarn' Stylee, none of that data came from the trig point itself; although it did rather huffily indicate North. It doesn't even indicate when it was built, although it looks like less than 5 years:-

http://i2.tinypic.com/x534he.jpg

http://i1.tinypic.com/x53535.jpg

http://i3.tinypic.com/x535sp.jpg

About a meter away at ground level was what probably amounts to a more up-to-date version of the Chi Node than I have previously been used to, judging by the 'GPS' stamp on it. This apparently marks the temple boundary. Temples have a long history of encroaching and being encroached on. I suspect that the Lands Office was asked by the abbott to establish the Temple boundaries once & for all. In fact, I sort of vaguely remember such a problem at this temple being reported by the Bangkok media. It was obvious that the temple gate lies well outside the boundary, although I doubt MOST villagers would see anything very objectionable about that. It probably lies on the 'property' of a Provincial or Rural Development Dept. highway anyway: -

http://i3.tinypic.com/x537fd.jpg

http://i1.tinypic.com/x53uzd.jpg

[Wisarut]

Ive seen another GPS Triangulation at Phrommathep Cape, Phuket and of course there is another GPS Triangulation at the top of Doi Inthanon even thoghh I have not seen by my own eye yet .... :)

[dick]

Khun Wisarut,
Since 1963 it belong to my profession to work with triangulation points. On my trips abroad I mostly spent some time to find some. Just in februari past I've made a picture of the Doi Inthanon triangulation point. Next week I will post it for the 2Bangkok forum.
Always a special point is: the center of a country. In The Netherlands the "Onze Lieve Vrouwentoren" in Amersfoort with coordinates x=00.00.00 and y=00.00.00
I think the Triangulatian points in Thailand are rather old?

[jpatokal]

Always a special point is: the center of a country. In The Netherlands the "Onze Lieve Vrouwentoren" in Amersfoort with coordinates x=00.00.00 and y=00.00.00
Speaking of which, what is the center point of Thailand for eg. road distances? The City Pillar in Bangkok?

[dick]

The city pillar the centre of Bangkok: Yes, emotional. In history: yes. But geografical at the moment: No. But centre of Thailand? Possible, we have to analise the mapping history. Until 1875 no strict cartographic programme existed in Thailand. Mapping of the city of Bangkok and charting in the aerea of the Gulf of Thailand was carried out by a mapping division, first established in Thailand in 1875.
Back to triangulation. Let's forget the history between 1875 and 1906.
Since the beginning in 1906 up to the present, the geodetic survey has been established: 7 base lines; 362 first-order triangulation stations; 40 first-order astronomical observation stations; 8,110 first-order leveling bench-marks (covering 13,414 km); and 1,500 gravity stations.
Map of triangulation net follows.

[GWR]

GPS Utility has some pretty nifty features for the rank amateur such as myself. Especially for Freeware:-

http://www.gpsu.co.uk/

It allows you to change the Datum to a number of commonly used datum, but if you look harder it also has a list of other more obscure datums that can be used. One of these is 'Indian Thailand'.

Any comment on this Dick? I notice that my collected data correlated quite well with 1:50,000 RSTD maps when 'Indian Thailand' was used rather than WGS84. Is this a good idea when comparing RTSD maps and GPS data?

Also any comment on the notion that at some point in its history GPS data was deliberately made rather inaccurate to prevent it being used for offensive purposes against the USA? Has anything really improved? It certainly isn't perfect!!

[ncr]

... it also has a list of other more obscure datums that can be used. One of these is 'Indian Thailand'. I notice that my collected data correlated quite well with 1:50,000 RSTD maps when 'Indian Thailand' was used rather than WGS84. Is this a good idea when comparing RTSD maps and GPS data?Ugh, map datums - a very difficult topic. Only that much: as the earth is not a perfect sphere (not even a regular oblate sphere; rather a potato!), it is useful to have different methods for different areas when projecting its surface onto a two-dimensional map. This is accomplished by using different reference spheroids (ellipsoid models) that best fit a particular region. Positions usually vary by several hundred meters between these. And in order to accurately compare between them, a nasty mathematical thing called reprojection is needed.

Now, RTSD used to use the 'Indian Thailand 1975' datum for their older map series. So it's no wonder if your readings correlate well with some of their maps (not sure when they changed, supposedly sometime in the 1990s, and there are still many older issues around). This is a regional reference system for mainland SEA, I guess. I wouldn't call it 'obscure', but it is actually obsolete. Basically all modern maps use WGS 84. Nonetheless, we need to be aware of its existence. On professional topo maps (but also on some tourist maps), the datum is noted somewhere at the bottom. A position in Indian Thailand is somewhere in the range of 450m to the southeast of a position in WGS 84 (but this varies with the location within Thailand).

As to your question: It is never a good idea to blindly try a map datum (could land you way off the mark); it is a good idea to check and make sure what should be used (e.g. what the map makers have used, when locating a GPS position on a map).

Also any comment on the notion that at some point in its history GPS data was deliberately made rather inaccurate to prevent it being used for offensive purposes against the USA? Has anything really improved? It certainly isn't perfect!!So you think it's a legend? No, no, that effect was real. It is called Selective Availability (http://en.wikipedia.org/wiki/Selective_Availability#Selective_availability) and was turned off at midnight on 02/05/00. Nothing to add to that article, except that I remember how I noticed a sudden and very significant improvement of the EPE (Estimated Position Error) reading of my Garmin in May 2000, cruising over a lake in Australia's Northern Territory, and was rather perplexed by it until I found out what had happened..... (the best value you used to get prior to this was maybe 25m, and if the conditions were not perfect, it often lingered around 100m!)

The Wikipedia article also links to this official announcement (http://www.ostp.gov/html/0053_2.html) by the US President.

And this (http://www.ngs.noaa.gov/FGCS/info/sans_SA/compare/ERLA.htm) is a pretty good illustration of the difference in accuracy.

[GWR]

Thanks for the interesting answer.

[GWR]

And the second read of that is even more interesting!!

I just took a close look at my complete stock of RTSD's and found that ALL of the 1:250,000 and 1:50,000 are all shown as using 'Indian Datum'. The most recent dates seem to be 1993. To put things in perspective, I see to be getting GPS readings that sometimes claim to dip to as low as 5m. The 1,250,000 maps have a printed variation of 125m, with some older ones at 150m (Yes, some of them were pre 19750. That doesn't surprise me much. Unfortunately, no such figures are given on the 1:50,000.

So it seems I may not be too wide of the mark in taking readings off the maps and then feeding them into the data set for GPS Utility set on Indian Thailand Datum. If you then change to the WGS84, the coordinates seem to adjust automatically; and I'm not going to use anything other than WGS84 in the field.

I guess you can get some sort of transparent graticule for taking coordinates off 1:50,000 maps. I made my own rather crude version using a long sheet of diagonally folded calendar paper, so it would reach across the map between the side markings. I then figured out a graduation and marked it on the side of the paper with a scale ruler. Primitive, but probably good enough for some of the stuff I want to do.

Is it OK having the GPS receiver set to TRUE NORTH for the sort of small-scale messing about I intend to do? That does seem to be its default setting.

I seem to have hit on a small snag uploading maps. It seems one often wipes off another and I'm wondering if it's because they are overlapping. I'm going to try out uploading a map that definitely doesn't overlap an existing one and see if they can coexist. I appreciate there is a function to select which mapping will be visible in MAP SETUP. So it's not just a case of having deselected maps in the receiver.

But no problem anyway! It seems I can always upload stuff as I need it, from this computer.

[GWR]

But don't get too excited for a few years just yet. Note that Pattani, Yala and Narathiwat are totally out of the question right now. No doubt the army has quoted their usual wornout security concerns, but in fairness it would be extremely difficult to survey the area in the current troubles.

http://www.nationmultimedia.com/2006/07/17/business/business_30008855.php

Maps available to government agencies to lift levels of service

The Land Development Department will provide its Colour Autophoto Maps at scales between 1:4000 and 1:25,000 by the end of this year.

Chaiwat Sittibush, director-general of the department, said it had completed Color Autophoto Maps nationwide except for three provinces in the South.

In the initial stage, the department will provide government agencies such as the Education Ministry, Natural Resource and Resources Ministry, Interior Ministry and Agriculture and Cooperatives Ministry with 1:4000 maps, covering 513,889 square kilometres with an accuracy of 95 per cent.

He said the maps had an important role in national development since government agencies could consult them to improve service. Users can monitor traffic, land use, public areas, agricultural activities, forest resources, forest fires, flood risks, disasters, coastal zones and national security.

He said the maps would reduce complexity and save money for government agencies, which now could all use their own maps with the same format.

The department will provide the maps to all government agencies though the Internet. The agencies who want to use or purchase them just enter the website and stipulate the areas they are interested in.

"The Land Development Department will provide the maps over the Internet in real time for an affordable fee of around Bt600 per four square kilometres," Chaiwat said.

The department plans to make the maps available to the private sector over the Internet as the next step. He said the department had started to develop new maps a couple of years ago with a budget of Bt800 million.

Jirapan Boonnoon

The Nation

[ncr]

I assume they are talking about "Colour Orthophoto Maps", i.e. rectified and mosaicked aerial photo maps. No hint whether that just means plain rasters, or includes derivatives such as digitized vectors. (But I happen to know that LDD will begin with a nationwide land use classification from airphotos soon.)

So this has nothing to do with ground surveys (unless they still need to collect Ground Control Points for orthorectification), and I don't know why they haven't completed the three southern provinces yet?

The word "auto" is nonsense in this context. :eek: