Drawing concentric circles that correspond to free space loss formula?

I want to be able to draw a circle with 50km radius and then fill the circle with values corresponding to the free space loss formula below:

FSPL(db)=20 log10(d)+20log10(f)+32.44

for example:

a circle of 50km around the "west Myara site" and then for every pixel(I guess) I would like to know its corresponding FSPL value and have it colored accordingly.

would I have to convert the polygon to a raster and then use the raster calculator to produce the values of each cell/pixel? if thats the case I would need to find the distance of the pixel/cell from the center point (in this case "west of Myara site" point) and how would I do that ?

• What f and d represent ? Jul 19, 2016 at 2:08
• @nickves F=frequency(in MHz)and D=distance(in Km), so distance would be the distance between the cell and the centre point "West Myara..." and Frequency would be any of these 5,6GHz,8GHz,11GHz, and so on(any Microwave tech) Jul 19, 2016 at 3:10
• How are you going to specify freq? How are they displayed when there are multiples? Jul 19, 2016 at 3:41
• I will perform the analysis for each of those frequencies. ultimately I would like to produce such circles for each of our sites(1000's) for each frequency Jul 19, 2016 at 3:53
• You have a QGIS tag but make no mention of what you have tried to do with that software to answer your question prior to posting it.
– PolyGeo
Jul 22, 2016 at 8:10