I'm looking to buy a GPS receiver to determine my exact position in Bangkok. There are a lot of products claiming great accuracy.

However, I just had a conversation with a friend about the GPS issue in Thailand. His company partner calls himself a leader in the navigation business.

He says that the hardware is compatible with Asia satelite systems, but the specifications are often for operations in North America and not using the Asia based satellites.

He says there are just 3 permanently reachable satellites (depends on time). Some GPS receivers have good specifications in North American, but cannot determine their location in Thailand any closer than 1.2km. The software can recalculate to 400 meters (with additional inputs).

I find this really hard to believe. Does anyone have any experience with this?

Also, if you do have good experience to within 10 meters, what is an economical brand of GPS receiver on the market here in Thailand?

It just seems to be such a valuable product for both travellers and business people that surely demand would result in a better satellite system and receivers.

Obviousely your friend knows nothing about GPS. The satellites used are the same all over the world, these satellites are not stationary but travel around the globe.

The accuracy is the same all over the globe except for the polar areas. You normally have 6-10 satellites available at any time in Thailand.

You should have 5-10m accuracy for most of the time with a decent receiver.

I'm looking to buy a GPS receiver to determine my exact position in Bangkok.  There are a lot of products claiming great accuracy.

However, I just had a conversation with a friend about the GPS issue in Thailand. His company partner calls himself a leader in the navigation business.

He says that the hardware is compatible with Asia satelite systems, but the specifications are often for operations in North America and not using the Asia based satellites.

He says there are just 3 permanently reachable satellites (depends on time).  Some GPS receivers have good specifications in North American, but cannot determine their location in Thailand any closer than 1.2km. The software can recalculate to 400 meters (with additional inputs).

I find this really hard to believe.  Does anyone have any experience with this?

Also, if you do have good experience to within 10 meters, what is an economical brand of GPS receiver on the market here in Thailand?

It just seems to be such a valuable product for both travellers and business people that surely demand would result in a better satellite system and receivers.

<{POST_SNAPBACK}>

I use my gps in the middle-east and if it can work here then it work in thailand as well. all you have to do is download a map of thailand or asia into our gps so you are going to have to get a pretty good gps system like a Garmin. It will cost you between $200 and $300. Just make sure that you can hook it up to a computer and you can download the enire freakin world if you want. Downloading maps may cost you a little though.

I'm looking to buy a GPS receiver to determine my exact position in Bangkok.  There are a lot of products claiming great accuracy.

However, I just had a conversation with a friend about the GPS issue in Thailand. His company partner calls himself a leader in the navigation business.

He says that the hardware is compatible with Asia satelite systems, but the specifications are often for operations in North America and not using the Asia based satellites.

He says there are just 3 permanently reachable satellites (depends on time).  Some GPS receivers have good specifications in North American, but cannot determine their location in Thailand any closer than 1.2km. The software can recalculate to 400 meters (with additional inputs).

I find this really hard to believe.  Does anyone have any experience with this?

Also, if you do have good experience to within 10 meters, what is an economical brand of GPS receiver on the market here in Thailand?

It just seems to be such a valuable product for both travellers and business people that surely demand would result in a better satellite system and receivers.

I wouldn't have thought you would need a GPS to find your way around, Vasco.

AFAIK the GPS satellites are in low polar orbits and go round twice a day. The satellites we can see also fly over Europe so I can't see that the accuracy is any worse in Asia than anywhere else.

Good info here http://electronics.howstuffworks.com/gps.htm

Now, as to the accuracy of the maps incorporated in the GPS receivers, a whole different story.

There are no 'asia based satellites' for GPS. They are 24 US DOD satellites that orbit the earth twice a day. 3 satellites in view are required for 2D mapping and 4 are required for 3D (altitude) mapping. The precision of the GPS signal itself is about 20 meters (65 ft). Using differential GPS and other error-correcting techniques, the precision can be improved to about 10 cm (4 in).

http://www.athailand.com/cgi-bin/AthBiz/Bi...Cat=Nav&Sub=Gps

I'm looking to buy a GPS receiver to determine my exact position in Bangkok.  There are a lot of products claiming great accuracy.

However, I just had a conversation with a friend about the GPS issue in Thailand. His company partner calls himself a leader in the navigation business.

He says that the hardware is compatible with Asia satelite systems, but the specifications are often for operations in North America and not using the Asia based satellites.

He says there are just 3 permanently reachable satellites (depends on time).  Some GPS receivers have good specifications in North American, but cannot determine their location in Thailand any closer than 1.2km. The software can recalculate to 400 meters (with additional inputs).

I find this really hard to believe.  Does anyone have any experience with this?

Also, if you do have good experience to within 10 meters, what is an economical brand of GPS receiver on the market here in Thailand?

It just seems to be such a valuable product for both travellers and business people that surely demand would result in a better satellite system and receivers.

<{POST_SNAPBACK}>

Just now I took my Magellan GPS (bought in the US) out on my porch overlooking the Chao Phrya River and I picked up 5 satellites. I have used a GPS in BKK for a number of years and it works perfectly here.

AFAIK the GPS satellites are in low polar orbits and go round twice a day. The satellites we can see also fly over Europe so I can't see that the accuracy is any worse in Asia than anywhere else.

Good info here http://electronics.howstuffworks.com/gps.htm

Now, as to the accuracy of the maps incorporated in the GPS receivers, a whole different story.

<{POST_SNAPBACK}>

I tested the Garmin Street Pilot 2610 here in BKK. The maps were excellent and the verbal direction commands could be toggled between Thai and English. I did not buy it as it could not see through my windscreen....I would have had to get a magnetic attachment for the roof. My friend who is a local Mercedes saleswoman uses one and she is very happy with it.

I might reconsider as there are some newer brands on the market.

If anyone has seen something new I would really like to hear about it.

Edited November 15, 200520 yr by corkscrew