2

My question can be divided in 3 steps and I guess I can answer 1.5 of them already.

To perform the viewshed analysis from every single pixel in a raster I will need:

Now the 3 steps are:

  • STEP 1: Get the points layer from the raster

This is my raster: enter image description here What I've done was used Raster Pixels to Points tool: Raster Pixels to Points and then I got this layer: enter image description here which I think it's was I need for step 2.

  • STEP 2: Perform Viewshed Analysis for each Point

As I said I would use one of those plugins/tools, but since the one use in GRASS requires to select one pixel at a time, I was trying to used the other one (QGIS plugin for visibility analysis). So here is the configuration of the tool that I used: enter image description here

--> From this point on I have problem achieving what I wanted <--

After I run it I have an error associated with the fact that I am not passing some fields ( which I think are also fundamental, observ_hgt and radius) and I don't know either where to put them... enter image description here

I even tried to add the fields observ_hgt with the value 1.5 and radius 2000 to each pixel (by clicking Toggle Editing > Open Field Calculator) but afterwards I got another error (as can be seen below): enter image description here

From this point on I don't know how to proceed and even Step 3 I don't know how would it be possible to achieve. But what I had in mind was to get an output like this...

{
  "70.24,214.22": {
    "visible_coordinates" : [ "70.23,214.24", "70.27,216.24",.... ]
  },
  "70.24,215.22": {
    "visible_coordinates" : [ "70.23,214.24", "70.27,216.24", .... ]
  },
  "70.24,216.22": {
    "visible_coordinates" : [ "70.23,214.24", "70.27,216.24", "70,4...." ]
  },
  .........
}

I said JSON but what I need is a way to get the information easily using python of knowing this: given a pixel coordinate, from which pixels is it visible? (something like reverse viewsheding, hope this isn't that dumb to say)

How do I solve Step 2?

closed as too broad by PolyGeo Apr 16 at 12:22

Please edit the question to limit it to a specific problem with enough detail to identify an adequate answer. Avoid asking multiple distinct questions at once. See the How to Ask page for help clarifying this question. If this question can be reworded to fit the rules in the help center, please edit the question.

  • If you are stuck on Step 2 then that is what I think you should focus this question on. You can always ask about step 3 in another question. – PolyGeo Apr 16 at 12:23