Not really very GPS literate, hope somebody can help me.

A friend has given me the co-ordinates to his house to six decimal points but my Nuvi only seems to have five so rounds it up. So 13.***476N becomes 13.***48 and 100.***941E becomes 100.***95E, not really sure how accurate these things are so would the five decimal points get me there?

Anybody know if and where I can update maps for my GPS, the current ones are listed as being 2007?

Thanks

One degree of latitude is comprised of 60 minutes. A minute of latitude is what defines a nautical mile. A nautical mile is very close to 2.2 km.

So there are 60*2.2 = 132 km in a degree of latitude. So 6 decimal places would define an accuracy of 132,000/1,000,000 which is about 13 cm, so the 5th decimal place will be accurate to about 1-2 metres.

So 4 decimal places would be accurate enough!

GPS units are not that accurate anyway. Even with the ability to see 6+ satelites they have an accuracy of no better than a few metres (usually between 3 - 10 m), so quoting to the nth degree of decimal is only an "accurate approximation" (to quote an oxymoron).

The difference would not be more than 1 meter.

Thanks chaps

One degree of latitude is comprised of 60 minutes. A minute of latitude is what defines a nautical mile. A nautical mile is very close to 2.2 km.

So there are 60*2.2 = 132 km in a degree of latitude. So 6 decimal places would define an accuracy of 132,000/1,000,000 which is about 13 cm, so the 5th decimal place will be accurate to about 1-2 metres.

So 4 decimal places would be accurate enough!

GPS units are not that accurate anyway. Even with the ability to see 6+ satelites they have an accuracy of no better than a few metres (usually between 3 - 10 m), so quoting to the nth degree of decimal is only an "accurate approximation" (to quote an oxymoron).

A nautical mile is 1,852 mt.

Anybody know if and where I can update maps for my GPS, the current ones are listed as being 2007?

Which map(s) do you have installed now? Tools/Settings/Map/Map Info should get you a list of the maps installed.

Anybody know if and where I can update maps for my GPS, the current ones are listed as being 2007?

Which map(s) do you have installed now? Tools/Settings/Map/Map Info should get you a list of the maps installed.

Thailand StreetMap v8.10 NT [English]

Anybody know if and where I can update maps for my GPS, the current ones are listed as being 2007?

Which map(s) do you have installed now? Tools/Settings/Map/Map Info should get you a list of the maps installed.

Thailand StreetMap v8.10 NT [English]

Latest version of Thailand StreetMap is v10.1. It can be purchased and/or downlloaded via ESRI website here: My link, you will need to register your GPS. Can also be purchased from Garmin retail dealers for 2,000 baht.