I need a way to get an alert when two events are close to each other (two peoples are meeting, two airplanes are too close etc.)
I could not find any simple way to do it.
There are 2 ways that you could approach this depending on what type of alert you are interested in:
1. The actual geometries of the GeoEvents touch (ie: when two GeoEvents collide)
2. The geometries fall within a certain threshold distance (ie: when two GeoEvents enter a specified distance from each other)
The first scenario is pretty easy, and it would involve setting a filter to evaluate the spatial relationship between the geoevents (intersects any) which would send an alert any time 2 geoevents intersected.
The second scenario is more common, and still pretty easy to setup. You would use a GeoEvent Processor in your GeoEvent Service to create an on-the-fly buffer ring around each geoevent. The buffer ring would be set at to output your specified distance (ex: 1 mile around each aircraft in the air) and would apply to each event. You would then set a filter to evaluate the spatial relationship of the buffer rings, and send an alert when 2 buffer rings intersect.
Here's the documentation on the Buffer Creator as well as the other processors that come default with the GeoEvent Server:
Processors—Real-time Data Feeds and Sensors (10.5) | ArcGIS Enterprise
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