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I have 200 gps points. I want to calculate total population living within a 5 km radius of the GPS point. I have a input raster for population.

What is the most efficient way to make these calculations? Would it be possible to use focal statistics, or would I have to create a buffer around each GPS point and then run some script to calculate the zonal statistics for overlapping polygons?

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I would:

1) Use Focal Statistics with a circular neighborhood of radius 5 km and statistics type "SUM". (This will create a raster in which each cell gives the sum of the population within 5 km).

2) Use Extract Values to Points with your 200 points as input point features and the raster created in step 1 as the input raster. (This will create a new output feature class that attaches the total population within 5km values to your point features).

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  • Very effective approach. If the raster resolution for population grid is 5km, the focal statistics might not be very accurate. To increase accuracy of the focal statistics, would it make sense to resample the raster to a finer resolution (say, 50m) and use this as the input raster for Step 1?
    – gis_user
    Commented Nov 18, 2016 at 19:14
  • @gis_user I agree that a finer resolution than 5km pixels would be better for this analysis. However, I'm not sure resampling will make your result any more accurate if the data you have was collected at 5km resolution.
    – K. Credo
    Commented Nov 22, 2016 at 18:20

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