How to interpolate on an irregular grid ?

[HansWerner]

Think of radio signal measurements.

You drive around by car equipped with an spectrum analysator and a GPS mouse.

So you get the coordinates x,y,z and the strength of the signal (peak in a frequency span).

I have a LabView program for that. At the moment I get a CSV file.

Assume that you only measure your own signal nothing else.

So there is no regular grid.

So how do I get the interpolation for coordinates x,y (z depends on x,y) ?

My first thought was to build triangles by delaunay triangulation and calculate the signal strength of a coordinate x,y by interpolation of the signal strength of the three corners of the triangle.

Yes I know the signal strength can change significant on a distance of only a few meters.

But you can't measure some square kilometers by a grid of only a few meters.

What do you think of delaunay triangulation, interpolation method, VIs that can be used ?

[altenbach]

You could use the mathscript griddata function.

[HansWerner]

How do mean that ?

I don't have a z coordinate.

Do you mean to use the signal strength as z ?

Also I have to transform GPS coordinates  (Longitude, Latitude) to something like UTM coordinates.

[altenbach]

---

HansWerner wrote:

I don't have a z coordinate.

---

Hhhmmmm....

---

HansWerner wrote earlier:

So how do I get the interpolation for coordinates x,y (z depends on x,y) ?

---

Yes, you would use the signal strenght as z if that's the function you want to map into a regular grid.