# Improve Accuracy of a Geographical POLYGON

### Pertanyaan

• Hi All,

The situation is like:

We have marked an area(POLYGON) with few points.{Say, it is POLYGON1}

Later, user wanted to mark the land/ POLYGON again with much more points.{Say, it is POLYGON2}

Now, we need to improve the accuracy of the polygon using all the points. Can we merge these two Polygons somehow to improve the accuracy?

[The main problem I am facing is while creating a new polygon with all the points(lat,long) used in POLYGON1 and POLYGON2. Can't get the proper Ordering to find the polygon. We can't neglect the POLYGON1. How to deal with?]

Any suggestion is appretiated. Thanks a lot in advance.

Mayukh Roy

29 Maret 2012 14:31

### Jawaban

• But they both have a zig-zag, just in different directions! I'm not quite sure what you mean by "uneven" shapes, but the land plots I'm familiar with can certainly come in all sorts of unusual shapes.

I'm afraid that I can't really understand your business rules as to how you want to reconcile the two sets of points, which is kind of crucial to being able to help answer your question.

• Disarankan sebagai Jawaban oleh 02 April 2012 2:15
• Ditandai sebagai Jawaban oleh 06 April 2012 1:36
30 Maret 2012 11:11

### Semua Balasan

• Have you tried creating a STUnion() of the two polygons? That will create a new shape that encompasses all the area contained in either Polygon.

29 Maret 2012 18:09
• Hi tanoshimi,

Thanks.

But, We dont need the union of two polygons. Here 2 polygons are defining same land on the earth, measured approximately.  My Problem is, I can't

place the points in proper order.

Mayukh Roy

30 Maret 2012 5:56
• I'm not sure how you're defining what the "proper" order is...?

Suppose the your two polygons are as shown below - they differ only in the placement of one point on the bottom edge.

Which of the possible solutions on the right hand side is correct, and why?

30 Maret 2012 7:21
• Hi Tanoshimi,

We consider the second one as correct as the lands we are measuring, is planned plots. So, no zig-zags or uneven shapes.

Thanks a lot...

Mayukh Roy

30 Maret 2012 10:15
• But they both have a zig-zag, just in different directions! I'm not quite sure what you mean by "uneven" shapes, but the land plots I'm familiar with can certainly come in all sorts of unusual shapes.

I'm afraid that I can't really understand your business rules as to how you want to reconcile the two sets of points, which is kind of crucial to being able to help answer your question.