please discuss the impact of the PPM values
In one of your captures, values are listed for PPMs. Can you discuss these values?
please discuss the impact of the PPM values
> In one of your captures, values are listed for PPMs. Can you discuss these values?
That's just another way of expressing the distance uncertainty, i.e. 95%-confidence distance uncertainty/overall distance x 10^6 = PPM uncertainty.
I don't consider it to be an exceptionally useful measure for ordinary boundary surveying. At least, I can't recall ever finding the PPM uncertainties worth examining because they deal just with the distance uncertainties and neglect the contributions of the uncertainty of the bearing between the points.
Not Click on Kent's Posts, Mr. Beaver?
That is not an option.
Even when he's boring, he's amusing, until about the 47th post.
That's when I start to get a little petty.
That is, of course, my problem, not Kent's.
I just like to snipe occasionally, and then get put in my place.
It's a hobby.
🙂
Don
Not Click on Kent's Posts, Mr. Beaver?
LOL!
Personally, I'm getting used to "getting put in my place" at this forum. Sorta like the relationship with my wife, I'm just used to getting told I'm wrong. Why would an interweb forum be any different?
> So thanks for post like this Kent!
:good: :good:
Modular Design of Network - Star*Net
> "U" is for Up.
"Up" being normal to the ellipsoid, or so I've always assumed. But it just occurred to me to wonder "what part of the ellipsoid?" At the vector origin, the vector endpoint, the vector midpoint, the project centroid, or yet some other location? Anyone know offhand?
Modular Design of Network - Star*Net
> "Up" being normal to the ellipsoid, or so I've always assumed. But it just occurred to me to wonder "what part of the ellipsoid?" At the vector origin, the vector endpoint, the vector midpoint, the project centroid, or yet some other location? Anyone know offhand?
Surely it's the local tangent plane at the point of origin of the vector. Nothing else would make much sense.
Modular Design of Network - Star*Net
> > "Up" being normal to the ellipsoid, or so I've always assumed. But it just occurred to me to wonder "what part of the ellipsoid?" At the vector origin, the vector endpoint, the vector midpoint, the project centroid, or yet some other location? Anyone know offhand?
>
> Surely it's the local tangent plane at the point of origin of the vector. Nothing else would make much sense.
From Wikipedia:
Local east, north, up (ENU) coordinates
In many targeting and tracking applications the local East, North, Up (ENU) Cartesian coordinate system is far more intuitive and practical than ECEF or Geodetic coordinates. The local ENU coordinates are formed from a plane tangent to the Earth's surface fixed to a specific location and hence it is sometimes known as a "Local Tangent" or "local geodetic" plane. By convention the east axis is labeled x, the north y and the up z.
