I am having a problem making a viewshed analysis for every pixel on a raster. To perform the viewshed analysis from every single pixel in a raster I will need:

This is what've done - 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

  • Please add the error messages as text instead of images. Text in images is difficult to read on some screens, and it isn't searchable. – csk Apr 23 '19 at 19:52

When you click on the Help button in the lower right, you get some, but not really clear informations.

I think you need to add those fields observ_hgt and radius from your error message to your point dataset. The already present id column holds the pixel value, which is your hight value of the DEM at this point. This one has no relevance for the observer and can be deleted.

The help page also states

Only projected raster data can be used. Latitude/longitude “projections”, such as WGS84 are not allowed.

From your screenshot it is clear that your DEM is in EPSG 4236, so indeed unprojected. So you need to reproject your DEM to a projected CRS in a first step, then create your points from it and then add the two columns with meaningful values.

Maybe there are also memory constraints due to the size of your DEM, so better make first tests with a limited selection of points to perform the analysis.

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