I have around 1000 GPS Points and want to calculate the average value of Night lights, within a 10 km radius in ArcGis. My first approach was to do this with buffers, but a lot of polygons overlap and Zonal Statistics is problematic. Which is why I decided to solve it with Focal Statistics. My approach would be:
1) Focal statistics with a 10 km radius
2) Extract Values to Points to get the respective value
However, when using Focal Statistics, I cannot specify kilometers (as I could for Buffers). Instead I have to specify the amount of map units of the radius. After reading through several forum posts, I figured that I somehow have to change the projection to a system where linear units (meters) are used. Is that correct? And if so, how do I know which one is the appropriate, as there are many systems that use meter? (Night lights have a CGS_WGS_1984 coordinate system).