Distinguish between new observations and truely new populations

[LienReyserhove]

It would be very good to distinguish between:

• new observations of a species that was already observed at a certain location
• first observations of a species that is new at that location

(I.e., not all new observations are new populations. To the contrary, all new populations are new observations.)

This distinction is important for the philosophy of the early alert system, and for the RIPARIAS project in general, which focuses heavily on early warning and rapid response.

I assume that this would require defining a distance from an observation to check for previous observations, or to check a given location (polygon) for previous records, or apply a grid under that same reasoning, or ...?