Avatar

JAG3D Introduction (Software)

Micha ⌂, Bad Vilbel, Samstag, 25. November 2017, 11:24 (vor 16 Tagen) @ Milos

Hi,

Datum should be defined with Y1, X1 and Y2. How to perform that action?

Okay, this is an academical example. You want to fix the components of point p1 and one component of the point p2. Thus, you have to define p1 as fixed reference point and p2 as stochastic point. Now, the trick is to fix the Y2 component of p2 by setting a height weight, i.e. a very small uncertainty, whereas X2 get a small weight, i.e. a large uncertainty.

Lets try an example taken from Benning (2007). It is a horizontal network containing four points, three sets of direction (in total 7 directions) and one distance group (in total 5 distances). Let us divide the points into two new points p3 and p4, one reference point p1 and one stochastic point p2.

new_points_2d.txt

3    0.0    0.0
4 1000.0    0.0

reference_points_2d.txt

1    0.0 1000.0

stochastic_points_2d.txt

2 1000.0 1000.0 0.00001 10000.0

The estimated coordinates are similar to the model, which defines the datum exactly by Y1, X1 and Y2. Anyway, this kind of datum definition is far away from practical use-case.

P.S. I guess this software works with classical way of defining datum parameters, am I right?

What does classical way means? JAG3D adjust a minimum constrain solution.

What about min trag defining of datum parameters?

I'm sorry. I'm not sure about the word trag. Can you explain the phrase min trag. Did you mean min trace? If yes, JAG3D minimises the trace of (a part of) the matrix Qxx.

regards
Micha

--
kostenlose Scripte und Software nicht nur für Geodäten || Portal für Geodäten mit angeschlossenem Forum-Vermessung


gesamter Thread:

 RSS-Feed dieser Diskussion