31 reputation
5
bio website
location
age
visits member for 2 years, 2 months
seen Oct 11 '12 at 13:35

Aug
1
comment Local Coordinate to Geocentric
Ok, updated and I expanded on the reasoning behind the steps. A library called geotrans does the heavy lifting for steps 1 & 2. As for the poles well...that was more of a guess I can't predict what will happen at the North pole. However, the South might work just fine. The issue was with how I was testing the accuracy. I used the extents of the level map to give offsets to apply to a hard coded point you wanted to test with. This is only test code so I didn't want to waste any more company time accounting for a map centered on a pole.
Jul
31
comment Local Coordinate to Geocentric
Thank you both for taking the time to answer my question, more later.
Jul
27
comment Local Coordinate to Geocentric
Yes, the forward vector would be north. Upwards would be vertically straight up in the air if that is what you meant by up.
Jul
27
comment Local Coordinate to Geocentric
Ultimate question added to the top of the post. I've even included the real values for the map I am using.
Jul
27
comment Local Coordinate to Geocentric
Mathematically you can't multiply a 3x1 vector but in programming your math library can, adding a 4th element W that is irrelevant and still return the desired 3x1 vector. I will add an example shortly showing conversion from local space to a point exactly on the prime meridian and equator.
Jul
27
comment Local Coordinate to Geocentric
Hi whuber, I've expanded on what I am doing in the original post.