Count number of Points within a varying distance

Question

I have a set of points (roughly 500,000 houses), and I would like to compute how many other points (sea buoys) are within a radius of each house. The search radius for each house is its distance to the horizon based on its elevation, so the search radius is not fixed (as with other tools) and is different for each house.

Is there a tool/method which would give an output of how many sea buoys are within the distance to the horizon of each house. so a column for house ID's and a column for number of sea buoys within its distance to horizon (I have already generated dist_horizon for each house).

I am using Arcmap 10.3 and I have a license for all tools as far as I know.

Answer 1

An option would be to assign the search distance to an attribute in the house layer.

Compute the buffer using this variable. Ensuring you don't dissolve the output (it's an option in the tool).

Then perform a spatial join between the buffer and the buoys.

You can table join the result back to your original house layer. Using the house Id as the link.

Answer 2

As each house is generating its own search distance I see no other way to process this data other than iterating over each house and identifying the sea buoys within the distance (as discussed by @Keagan_Allan). If you have already attributed the search distance to each house then a simple model in model builder could generate this data.

If you are not familiar with model builder then have a look at the help file, or attend a training course? Any sort of repetitious processing as you are seeking is best done in model builder or when you have hit the limitations of modelbuilder script it in python.