I am new to GIS and I desperately need some help.
I am creating a very basic tracking application and I use a GPS receiver which produces latitude and longitude coordinates.
I am using Navteq streets data and this uses the following projection:
ellipsoid - airy
I need to convert my latitude and longitude coordinates into the appropriate format for this map. I do not know what format this is. I have tried converting to UTM and that does not give me the right answer.
When i view a location on multimap this shows you the latitude and longitude coordinates for the location and some x,y coordinates. An example is shown below...
Location: United Kingdom
Grid ref: TA000000 Postcode district: DN21 4xx (map centre)
X: 500000m Y: 400000m
Lat: 53:29:14N (53.4872) Lon: 0:29:40W (-0.4944)
Web Address: www.multimap.com/map/browse.cgi?lat=53.4872&lon=-0.4944&scale=2000000&icon=x
I need to be able to convert my latitude and longitude coordinates into those x, y values in meters as that is what my map or my map software seems to use. I do not understand why but when i plot those x and y values on my map they come up at the right place.
Please can you tell me what system of projection those x,y coordinates are based on. Please can you also tell me a resource for converting between the two programmatically. I need the conversion to be very accurate. I am willing to pay. I need to be able to make the conversion from a vb.net program.
Thank-you very much for your help. This is an urgent problem.